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Soil science labs from Vernier (lots of great ideas in this video!!!!)

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Soil science labs from Vernier (lots of great ideas in this video!!!!)

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The Dirt on Soil Science: Engaging Experiments with Go Direct Sensors

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https://serc.carleton.edu/eslabs/carbon/1b.html?fbclid=IwAR2cYu_KYYWExtRW__9Ntz-zVFcwy4sBodKXHQGakuftTuCuHgLYb5vXh4I

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Submit a Google Doc for ease of comments (you can tag Ms. Kleven in a comment for feedback during the writing process too!).

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Submit a Google Doc for ease of comments (you can tag Ms. Kleven in a comment for feedback during the writing process too!).

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Research question (RQ) approved by October 9th

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Research question (RQ) approved by October 9th

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https://docs.google.com/document/d/1WhgvoyL8xmeXOjkzfUudOa8WeihVUgkexQ8s5fsxNQg/edit?usp=sharing

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https://www.biologyonline.com/dictionary/net-primary-productivity

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Biology Articles, Tutorials & Dictionary Online

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Net primary productivity
n., plural: net primary productivities
[nɛt ˈpɹaɪməɹi ˌprɒdʌkˈtɪvɪtɪ]
Definition: difference between gross primary productivity and the respiratory rate

In order to keep the biosphere running, different organisms play different roles and functions. Some help in oxygen production while others consume it for survival. Some die and decay, so that some others can absorb the nutrition and feed on them. There are innumerable interlinks and interconnections that keep the biosphere running in a loop year after year, era after era, and from times immemorial to the times to come.

The primary fuel for running the biosphere is sourced from the autotrophs ( primary producers) of a system. In this context, two topics become of significant importance - gross primary productivity (GPP) and net primary productivity (NPP). Let's learn what each of these terms stands for and how one should define NPP and GPP.

Net Primary Productivity Definition

Let's first understand what's productivity and the different types of productivity. Then, we will move ahead and try to decipher the meaning and differences between NPP and GPP.

1. Productivity (ecology) stands for the rate of biomass generation/energy addition/carbon fixation/organic matter addition.

2. Primary productivity (ecology) stands for the production of biomass from inorganic molecules. Here the main conversion is of inorganic minerals to organic biomass. This duty is performed by the "autotrophs" of the ecosystem.

3. Secondary productivity (ecology) stands for the production of biomass from organic molecules. Here the main conversion is of organic molecules to some other form of organic molecules. This duty is performed by the "heterotrophs" of the ecosystem.

4. Gross primary productivity (ecology) stands for all the carbon that's fixed by the primary producers of the ecosystem i.e., the main product of photosynthesis.

5. Net primary productivity (ecology) stands for the difference between all the carbon that's fixed by the primary producers of the ecosystem and the part of that fixed carbon that the primary producer utilizes for its own cellular respiration needs.

In biology, net primary productivity is defined as the difference of the energy that's fixed by the autotrophs and their own respiration losses. It is the net primary productivity that provides the channel for secondary productivity. For all the activities of consumers and heterotrophs, it's the NPP that provides the energy and biomass source. And that is how NPP is converted to secondary productivity in the form of heterotrophic tissue. Another point to note here is that secondary productivity is " always " limited by the NPP. So, when asked what is net primary productivity, one can explain it and the significance associated with it.

Biology definition:
Net primary productivity is s the difference of the energy that's fixed by the autotrophs and their own respiration losses. It is the rate at which an ecosystem accumulates energy or biomass, excluding the energy it uses for the process of respiration. This typically corresponds to the rate of photosynthesis, minus respiration by the photosynthesizers.

How Do You Calculate NPP?

Now, as you have become familiar with the NPP meaning, what is NPP, and the importance of net primary production, let's move ahead and learn the net primary productivity formula.
NPP = GPP - RR
Where,
NPP= Net primary productivity
GPP= Gross primary productivity
RR= Respiratory Rate

This formula is important as it diligently associates GPP to NPP and also makes the metabolic losses and respiratory losses of autotrophs/producers count.

Generally, NPP is calculated and measured at the level/scale of "ecosystem" and over relatively longer frames/intervals of time(such as a year/s).

Some Important Pointers Related to NPP

NPP is very commonly associated with the increase in biomass per unit time and surface area (land).
In a way, NPP can be calculated by relating it to photosynthesis. The rate of anabolic photosynthesis reactions can be measured and used to quantify NPP.

Common query: how does oxygen production relate to the rate of photosynthesis? And the answer to it is this: oxygen is the product of anabolic photosynthesis reactions, hence it's a product of NPP.

Not all the light energy captured by plants during photosynthesis contributes to NPP as parts of it get converted to organic matter, some other parts are lost as metabolic costs; others are dissipated as heat. Only the fixed organic matter that goes in the food chains, food webs, and in the subsequent trophic levels contribute to NPP.

Human colonies and societies are a part of the global NPP cycle but influence it in an inordinate way.

There are many factors on which NPP depends like:

Humidity

Temperature

Nutrient availability

Precipitation

Climate

Plant species and management

Initial biomass of the ecosystem (carbon-fixing plants/photosynthetic tissues)

The rate at which new biomass is assimilated

Net Primary Productivity Example

Some examples of net primary productivity are:

1. As we already know that the NPP is dependent on the "Initial biomass of the ecosystem (carbon-fixing plants/photosynthetic tissues)", hence the "stands" or "ecosystems" with extensive-standing biomass will always have higher NPP. So, when asked what is a high NPP, one can answer That- "stands" with high initial biomass and higher rates of biomass production. Example: Production forests are having higher NPP than stable forests.

2. Legume-rich agricultural fields and pastures tend to have higher NPP than legume-deficient pastures as legume biomass accumulation is never hindered due to nutrient deficiency (especially nitrogen).

3. Temperate forests have higher NPP than temperate grasslands.

Try to answer the quiz below to check what you have learned so far about net primary productivity.
References

Diaz S. (2013). Ecosystem Function Measurement, Terrestrial Communities. Encyclopedia of Biodiversity (Second Edition), 72-89.

DellaSala D.A. (2021). Imperiled Terrestrial Ecosystems: Nature in Retreat. Reference Module in Earth Systems and Environmental Sciences. https://doi.org/10.1016/B978-0-12-821139-7.00089-1

lark, D.A.; Brown, S.; Kicklighter, D.W.; Chambers, J.Q.; Thomlinson, J.R.; Ni, J. (2001). "Measuring net primary production in forests: Concepts and field methods". Ecological Applications. 11 (2): 356-370. doi:10.1890/1051-0761(2001)011[0356:MNPPIF]2.0.CO;2. ISSN 1051-0761

Sigman, D.M.; Hain, M.P. (2012). "The Biological Productivity of the Ocean" (PDF). Nature Education Knowledge. 3 (6): 1-16.

Wright R.T., Boorse D.F. Environmental Science: Toward a Sustainable Future (11th Edition) 11th Edition. ISBN-13: 978-0321598707

©BiologyOnline.com. Content provided and moderated by Biology Online Editors.

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Net primary productivity - Definition and Examples - Biology Online Dictionary

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Net primary productivity is the difference between the total energy that is fixed by the autotrophs and the energy expensed as their own respiration losses.

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Use this template! Delete the descriptions and add your information!!!

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Use this template! Delete the descriptions and add your information!!!

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https://docs.google.com/document/d/1btEhzIcapPt_neU1naviwqBKceXfxvZGS1cajY9cfA4/edit?usp=sharing

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CITE everything ... FROM THE BEGINNING OF THE IA PROCESS!!!!

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CITE everything ... FROM THE BEGINNING OF THE IA PROCESS!!!!

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https://docs.google.com/spreadsheets/d/1kSfxG6bTYmzob0Cqdrj537kj1Wj9sifDWHp5KEAwaz8/edit?usp=sharing

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https://docs.google.com/document/d/1eqaukL3gwV8rlU0UhG6XoQKitma0DqjSYixcJfRKyo0/edit?usp=sharing

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https://teachingapscience.com/water-quality-testing-lab/

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Water Quality Testing is essential for AP® Environmental Science students. Every released exam has water quality test questions. Water quality is usually covered in Unit 8, but some teachers cover in Unit 1 with aquatic ecosystems so they can do water testing before surface water sources freeze in the winter.

Ideally, taking kids to a stream or pond is best, but testing water quality in the field is not possible for my students in arid Southern California. Surface water is seasonal and often too far away. Instead, my students bring in water samples to the lab.

Water quality testing in the lab is the "elaborate" part of my Water 5E lab. Before they do this part, students do a "virtual" portion with 3 Explains/Explores that can be found on this link.

Next, students do real water testing. Click for the handout for students. You will need to change the handout to match the items you have for testing. Also, there is a link for our local water quality reports. Find your own local report and change the link.

These are my reference sheets-you will need to add or subtract by editing for the tests and devices you have in your lab. All links above are free. If you are looking for more resources for water pollutants, tests and a river pollution diagram, you can purchase here.

I demonstrate how to take a water sample for students. This year, I made a video which they enjoyed more than my demonstration.

Any empty bottle (water, Gatorade etc) works. Rinse out a little with the sample water and then fill under the water. Interesting water sources include rivers, creeks, ponds, lakes, well water, the ocean and fountains.

Ideally, students should wear gloves to collect the sample. But, if they forgot to bring gloves, they can throughly wash with warm water and soap after collecting the sample.

Students should cap the bottle under the water to prevent air at the top from skewing the dissolved oxygen (DO) results. Sometimes, this isn't possible (with a small creek or heavy waves in the ocean) so I tell them to do the best they can. There is some error as Biological Oxygen Demand will decrease the DO reading, but we discuss this.

Students need to label the bottles and bring to class on the day we do water quality testing.

I used a LaMotte water quality testing kit the first year I taught APES, but soon realized that probeware was more economical in the long run with the quantity of students I have. I was accepted for grant funding to purchase my initial probeware and have used science funds and donation money to replace items as needed. Read where to find science funding.

I use a variety of water quality testing devices that are easy to use. This is a folder with instructions for my various probes and test strips.

Reviews of wireless probes for the lab. I use a variety of probes and test strips (pictures below).
Hanna pH Meters
Pasco Sensors
Vernier Sensors

The collection below is what I currently use-requires little prep work on my part and works for an entire day-5 sections of APES students.

I rotate baskets instead of kids going to stations. This is easier with 36 kids in lab and then they don't have to travel with their water sample. I give kids about 4 minutes per basket and then they rotate clockwise. Kids also spend that time using reference sheets to see what the test measures and what are the levels for safe drinking water and for healthy aquatic life.

This is the LaMotte Testing kit I used before I received grant money to purchase my initial probeware 12 year ago.

Today, I use a variety of items that are reliable, economical for 165 kids in APES and easy to use. They've been acquired over a dozen years through various means and I've changed a few items over time. Most of them have links to Amazon if you want to read more about the item.

Fecal Coliform Bacteria is also very important, but also very expensive. If you have the funds, its great for kids to do in lab. If not, make sure they learn about it. This year, I made an instructional video instead of purchasing $100 worth of tests.

In years past, I have purchased Coliscan Easy Gel which works well and is easy to use. I've also used Petrifilm which is a little more economical for large classes.

Students also record odor and color, but those are observations.

Click for my water quality lab handout for students. You will need to change the handout to match the items you have for testing. Also, there is a link for our local water quality reports. Find your own local report and change the link.

These are my reference sheets. Again, you will need to add or subtract for the tests and devices you have.

Have fun water testing!

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Water Quality Testing in the Lab - Teaching AP® Science

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Water Quality Testing is essential for AP® Environmental Science students. Every released exam has water ...

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https://www.iucnredlist.org

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How to measure an ecosystem's resilience 

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How to measure an ecosystem's resilience 

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https://crowtherlab.com/how-to-measure-an-ecosystems-resilience/

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If you take a walk in a forest, you observe many details of that landscape: it might feature a wide variety of green colors, it might be home to many different species of trees, flowers, shrubs, moss - if you bend over, you can touch the soil and feel if it's compact or spongy and wet. By visiting a forest only one time, you won't aren't be able to observe how the forest changes over time. What happens to that forest if there is a wildfire? What happens if its major water spring dries up? What happens if an invasive species starts to take over the forest?

All of these questions lead us to question how resilient an ecosystem is. In order to understand how resilient any ecosystem is, you would have to visit it many times to observe how it changes over time.

Scientists at Crowther Lab are working to understand how ecosystems, like forests, change through time; especially how they change in response to particular disturbances. In light of climate change and biodiversity loss, this is particularly critical. Understanding ecosystem resilience is key to creating the scientific foundation for the protection and restoration of nature.

What is resiliency? From physics to ecology

The concept of resilience comes from studying how ecosystems change through time. Resilience is a complex concept which has impacts on many different topics and research areas - including in ecology. You might be surprised to learn that this concept originates from material physics - how raw material can be disturbed and still recover its original properties. Ecologists applied that same concept to the study of ecology.

The same principle applies to ecosystems: although ecosystems are much more complex because there are many different attributes to examine. Ecological attributes, also referred to as ecological characteristics, are features of a taxon such as its geographical distribution, climate tolerance, habitat types, soil carbon, water cycle, and so on. To understand an ecosystem, scientists first have to have a clear understanding of its attributes. What we study at Crowther Lab in particular is plants: it's possible to use data that shows how green an ecosystem is from space! This proxies plant photosynthesis, plant cover - and how green a place is in particular. It's this feature - greenness - that allows us to measure resilience.

How much time does an ecosystem take to recover from a disturbance?

So how do we measure the resilience of an ecosystem? Scientists measure this through time! But first, scientists have to define a stable state of an ecosystem as a benchmark. What is a stable state? This is the state to which the ecosystem will return when the system fluctuates naturally or because there is a disturbance. Scientists then measure how much time it takes to recover to that original stable state. This time of recovery depends on many things, for example, drylands and deserts are particularly slow at recovery; but more biodiverse ecosystems tend to recover faster than less diverse ecosystems. This concept is termed " the basin of attraction ".

What are alternative stable states in ecology?

But what if there is more than one stable state? Ecologists also understand that for certain systems, an ecosystem can have two alternative stable states. This means that under the same environmental conditions, the ecosystem can have two different states.

These states are separated by an unstable equilibrium that marks the border between the ' basins of attraction ' of the states. This pattern, in which the forward and backward switches occur at different critical conditions, is known as hysteresis.

What is a catastrophic shift in nature?

When an ecosystem has alternative stable states, it may shift or tip between those states. This transformation between alternative states is known as catastrophic shift or critical shift. This is a very important process because of several reasons.

Characteristics of catastrophic shifts

The transformation is usually drastic, meaning that the alternative states are fundamentally different states. Think for example, about a forest shifting into a grassland.This type of transformation may force the people living there to accommodate drastically to a new way of life. These shifts usually occur very abruptly with almost no time to adapt and because of hysteresis, transforming the ecosystem back to the previous state may be very complicated (or virtually impossible). This recovery to the original state does not usually occur spontaneously when the disturbance that caused the first transformation stops.

This happens in nature more often than one might expect. Take for example, the acidification of coral reefs or desertification of drylands. Many attributes can be affected by this catastrophic shift - but it is almost impossible for that ecosystem to recover its original properties.

Resilience and catastrophic shifts

The existence of catastrophic shifts has two major consequences for resiliency. When we define resilience as the time that it takes an ecosystem to get back to a "stable state", we anticipate that ecosystems will recover from disturbances. Because of catastrophic shifts, the time it can take an ecosystem to recover is - forever. This is especially the case if the ecosystem crosses into a different alternative state.

In fact - resilience is so important for the health of ecosystems that scientists have redefined this term . Now, we understand it as the ability of an ecosystem to absorb disturbances without changing its state. This was done to explicitly put the concept of states in the definition of resilience; this is how important the relationship between resilience and catastrophic shifts is!

When an ecosystem loses resilience, it opens the pathway to a catastrophic shift. Some researchers have suggested that if we note a loss of resilience in a system that we think may have alternative states, we should consider this an early warning sign that the system may transform into the alternative state. So systems that may tip between alternative stable states are simply systems with lower resilience than ecosystems that are less likely to change states.

What are the impacts of resiliency for restoration efforts?

Understanding ecosystem resilience helps scientists to understand the larger environmental context. If the critical work to restore nature does not consider the larger environmental context and stable ecosystem attributes, then they are unlikely to be successful. Understanding global ecosystems' resiliency is critical for restoration efforts or conservation measures to be successful in the long-term.

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How to measure an ecosystem's resilience? - Crowther Lab

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Time is critical to understanding resilience. We think nature changes slowly; it doesn't always. If you take a walk in a forest, you observe many details of that landscape: it might feature a wide variety of green colors, it might be home to many different species of trees, flowers, shrubs, moss - if you bend [...]

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Microbial growth and pH changes in five parks (scored a 7)

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Use a sampling strategy that you learned in 2.5!

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Use a sampling strategy that you learned in 2.5!

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Label every figure, image, table, and graph with a title and description. THE LABEL IS ABOVE!

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Label every figure, image, table, and graph with a title and description. THE LABEL IS ABOVE!

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ie Image 1: Cross streets of via Ripamonti and via Izonzo where carbon dioxide concentration was collected.

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Include both qualitative and quantitative data.

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Include both qualitative and quantitative data.

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Graph should include correct scale to visually understand the data.

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Graph should include correct scale to visually understand the data.

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Include equipment uncertainties in the materials list, raw data tables, processed data tables, and graphs.

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Include equipment uncertainties in the materials list, raw data tables, processed data tables, and graphs.

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Share FIRST DRAFT via Google Docs with Ms. Kleven

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Share FIRST DRAFT via Google Docs with Ms. Kleven

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Convert FINAL DRAFT into a .PDF and post on Schoology. This is to ensure formatting is correct.

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Convert FINAL DRAFT into a .PDF and post on Schoology. This is to ensure formatting is correct.

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Use Ms. Kleven's template instead of looking on Google for examples - they're probably wrong!

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Use Ms. Kleven's template instead of looking on Google for examples - they're probably wrong!

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Use My Maps to create or view your own maps.

Create a map

1. On your computer, sign in to My Maps.

2. Click Create a new map.

3. Go to the top left and click "Untitled map."

4. Give your map a name and description.

Open a map

1. On your computer, sign in to My Maps.

2. You'll see maps you've made or viewed as well as maps shared with you.

3. Optional: To see popular maps and staff picks, click Explore.

Change how a map looks

1. On your computer, sign in to My Maps.

2. Open a map you can edit or create a map.

3. Next to "Base map" in the bottom of the left panel, click the Down Arrow .

4. To choose a style, click one of the images.

View maps you can't edit

If you can open a map but can't edit what's on it, you're in the map viewer. While in the map viewer, you can still:

Search the map contents

Show or hide layers

View the map with satellite imagery

Share, export, and print the map

If you own a map and want to see how it looks in the map viewer, click Preview .

To ask for edit access for a map you don't own, contact the map's owner.

Related articles

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Create or open a map - Computer - My Maps Help

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Use My Maps to create or view your own maps. Create a map On your computer, sign in to My Maps. Click Create a

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Put the stats you learned in math class to work! Pearson's, chi squared, ANOL, etc. Do more than mean and standard deviation.

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Put the stats you learned in math class to work! Pearson's, chi squared, ANOL, etc. Do more than mean and standard deviation.

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Microplastic pollution and diversity (scored a 7)

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Buffer strips widths impacting nitrates and macroinvertebrates

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Don't include an appendix (they won't read it)!

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Don't include an appendix (they won't read it)!

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Identifying the context, planning, method & materials list approval by October 15th

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Identifying the context, planning, method & materials list approval by October 15th

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Submit Google Doc on Schoology.

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https://docs.google.com/forms/d/e/1FAIpQLSf6WypA-z35PUBWH8irIwgb1-zsnZpauHAs3T0kA8dk3rFhTA/viewform?usp=sf_link

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Complete at least one trial to see if you need to tweak your method.

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What is NOT included in your word count:

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What is NOT included in your word count:

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Headings, image/graph/table titles, data, and works cited page.

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Don't include processed data in raw data tables (such as mean or SD).

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Don't include processed data in raw data tables (such as mean or SD).

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https://ess.sciencesauceonline.com/the-ia/

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The individual investigation for internal assessment (usually just called "The IA") is a practical assignment that all ESS students will complete. This series of videos covers all aspects of the assignment from start to finish.

The ESS IA Video Guide Series

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Resources for IB ESS: Environmental Systems and Societies.

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https://www.sciencefriday.com/educational-resources/diy-groundwater-model/?fbclid=IwAR21nOwJ2GiG_iXPpwlET6mzu-DCJUzlHQmJEe5FUKbT_JpZ3oOjsSHNsU4

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In 2015, the Gold King Mine, a historic mine that was a toxic waste site, was being excavated by the EPA to begin the long process of cleaning up acid waste that had collected within the historic mine. Then the unthinkable happened: A major spill occurred, unloading millions of gallons of metal-contaminated acid mine drainage into a nearby river in a pollution event that would ultimately affect three states, and multiple Indigenous tribes in the region.

Hydrologist Karletta Chief stepped in, insisting on more careful analysis of water and sediment to ensure that the water was eventually going to be safe for the hundreds of ways that members of the Navajo Nation, her own Indigenous community, use the water.

Watch this video to learn about the Gold King Mine spill, and the efforts of one scientist to understand and mitigate its impact on the region.

Why do events like the Gold King Mine spill influence so many individuals, in so many ways? How does water travel above and below ground, and how can we use that information to predict who is affected by surface and groundwater contamination? To find out, you'll create a model of a shared natural underground water supply-a shared aquifer-and experiment with how simulated contaminants move through the aquifer by conducting your own water testing.

Educators, fear not: We've got DIY Groundwater Model Instructions that with a little elbow grease and $60 in parts will make 10 working groundwater models (for groups of three students) that you can use year after year!

Students will:

Model how a shared aquifer is affected by precipitation and acid mine drainage

Participants will monitor the acidity of water over time to ensure their simulated water supply meets National Secondary Drinking Water Regulations (NSDWRs) of 6.5-8.5 pH

Participants will use their data to map contaminant plume movement over time

Extension: Create and test a remediation solution

An Introduction To Groundwater

After a heavy rain, you'll likely see some standing water and a few puddles that collect on the surface of the ground. You might even see water flowing along roads and sidewalks into storm drains. But what you probably don't see is the incredible amount of water that is absorbed directly into the ground.

In most places that aren't covered by rock or asphalt, there are spaces between bits of rock and particles of clay and soil that provide pathways for water to travel after it rains. Thanks to all of these small spaces, the ground can absorb a lot of water. Beneath the ground we walk on, sometimes miles below the surface, large amounts of water can collect as groundwater. Wells, springs, and pumps make it possible for us to extract groundwater for many uses, including drinking and household use, agriculture, and manufacturing.

Groundwater doesn't always stay in one place, it can diffuse, drift, and flow from place to place underground. Similarly, when pollution spills onto the ground or leaks from a common source of pollution (called a point source) into lakes, streams, the groundwater that gets contaminated can move the pollution from place to place.

In order to understand how water, and water pollution, move through groundwater, it helps to master a little vocabulary:

Aquifer

An underground body of permeable rocks or sediments that is saturated with groundwater, which can be brought to the surface by a well or spring. Water can move from place to place within an aquifer. Aquifers can be very large, spanning many, many miles and providing drinking and irrigation water for multiple states.

Recharge

When it rains and water permeates into the soil, water can be added back into an aquifer. This is called recharge. In places where it is periodically dry and where aquifers are depleted by human activities, recharge can be essential for ensuring that water remains available for irrigation and drinking.

Porosity

The percentage of open space (pore space) in a rock or sediment sample. Sediments like sand, silt, and clay usually are very porous and can store lots of groundwater in the pore spaces. Many igneous and metamorphic rocks have very low porosity unless they are fractured.

Permeability

The rate at which water can flow through porous rocks or sediments. Permeable rocks and sediment allow well pumps to withdraw much greater volumes of water per hour than less permeable rocks or sediments and are recharged more quickly by rainfall.

Pollution Plume

A body of polluted groundwater. A pollution plume may flow and diffuse within an aquifer, affecting different areas over time.

Groundwater Checks For Understanding-With Graphics!

Answer each of the following questions, annotating and incorporating diagrams in your answers. Print out this worksheet version which includes diagrams to help you ( docx version).

1. Why would pollution contamination of an aquifer be potentially more serious (put more people at risk) than contamination of a small surface pond?

2. How do you think porosity affects the amount of surface water that will be absorbed and stored as groundwater following a rain storm? Why?

3. How would a recharge event, such as a series of rainstorms, affect the direction that a pollution spill at the surface might travel if the soil had high permeability? What if the soil had low permeability?

4. If there is a pollution plume on one side of an aquifer, and someone pumps water from the opposite side of the aquifer, do you think the pollution plume will move towards the pump, away from it, or stay in the same place? Why?

5. Explain how the porosity of soil might affect its permeability. If it helps, you can annotate the diagram below as a part of your explanation.

Groundwater And Coal Mines: Acid Mine Drainage

When underground water and air come into contact with the sulfur- and iron-containing rocks (for example pyrite) commonly found in coal mining operations, a chemical reaction can occur which forms sulfuric acid and iron dissolved in water. Through this process, old mining sites can become reservoirs of highly acidic, iron-rich groundwater that can leak out of the mine slowly (or in the case of the Gold King Mine be released and flush out quickly) and contaminate nearby aquifers, lakes, and streams. This pollution, called acid mine drainage, can turn lakes and streams yellow or orange, as occurred during the Gold King Mine spill described by Karletta Chief in the Science Friday video above.

Though water acidity is hazardous for plants and wildlife in its own right, it poses particular risk to humans because of its ability to dissolve heavy metals. As contaminated acid mine drainage comes into contact with rocks and minerals that naturally contain heavy metals such as lead, copper, arsenic, and mercury, those metals dissolve and are added to the water, resulting in highly toxic pollution that can contaminate drinking water and harm plants and wildlife.

Build A Groundwater Model

A good groundwater system should accomplish a few things: It should integrate porous sediment (sand), be rechargeable with water from above (to model precipitation), and incorporate one or more wells and/or pumps (to simulate human extraction of water from aquifers). You can purchase Groundwater Model Kits from various online providers ($200-$900 per model), however building your own using a plastic shoebox and condiment/shampoo pumps is reasonably straightforward and significantly less expensive ($70 for a set of 10 that works with 30 students). These models work year after year, so they are worth the up-front time investment of building them yourself.

Download the guides below, pioneered and perfected by veteran California earth science educator Ryan Hollister:

Each finished groundwater model should work and function like this:

The Groundwater Model Simulation: A Shared Aquifer

In this modeling exercise participants will experience the use dynamics of a shared aquifer system. Because this activity models a shared aquifer system, students will work in groups of three, each "living" on a simulated plot of land with its own "well" (pump). Students will pump water out of their wells to simulate withdrawal needs for the water users in a given month.

Groundwater Model Setup

Split students into groups of three "well owners," and provide each group with a groundwater model setup and three beakers with at least a 100ml capacity.

Fill each groundwater model with water until the water sits 1 - 2 cm above the surface of the sand.

Assign the students in each group to one of the three plots of land (each student should have their own pump).

Make up a recipe of acid mine drainage simulant for each student group using this acid mine drainage simulant recipe.

Have each group download a copy of the digital Well Monitoring Data Spreadsheet to track their pumping and contamination data throughout the simulation. Note: The virtual spreadsheet has cell calculations pre-populated to account for rainfall variability and generate rainfall and water pumping totals after each simulated month.

Provide a pH probe to each group OR set of 30 (3 x 10) pH indicator strips to test the pH of each well for 10 pumping simulation rounds.

Provide copies of the Printable Groundwater Simulation Instructions to walk students through each "month" of the simulation, described below.

Month 1: Typical Monthly Use

In this simulation, each month of use is represented by 60 seconds of active pumping. To maintain their quality of life, each well owner must pump between 90 and 100 ml of water from each well in a 60-second month. Once the month is over, no more pumping is allowed until the next month's rainfall.

1. All well owners: At the start of the timer (60 seconds), begin pumping steadily (not fanatically!) Stop as soon as your 60 seconds are up.

2. Measure and record the volume of groundwater pumped in "Month 1" of the "mL Pumped" column in the Well Monitoring Data Spreadsheet.

3. Use pH paper or pH probe to test the pH of each well's water and record the data in "Month 1" of the "pH" data table. This will be your baseline pH for the system.

4. Dump the pumped water down the sink after pH has been recorded.

You'll notice that when you add your pump volumes to the Well Monitoring Data Spreadsheet, it will automatically calculate the " Amount of Surface Water for Recharge " that will be contributed to the system's aquifer the following month. Recharge of aquifers happen when water from the surface of the earth infiltrates the pore spaces of the soil, sediments or rocks. Since monthly rainfall amounts in the simulation region are highly variable, the amount of recharge calculated each month will reflect that variability. The amount of surface water for recharge will also reflect the pumped volumes from the previous month to account for variability in the pumping efficiency of each pump and well owner.

Month 2: Recharge And Acid Mine Drainage Contamination Event

Owners of Well #2 and #3:

1. Use tap water to fill graduated cylinders with the amount of water needed for recharge calculated by the spreadsheet.

2. Slowly pour out the water to "make it rain" over each well's parcel of land. The water should drain through the box-top's holes.

Owner of Well #1

1. Oh no! Acid mine drainage has contaminated the land and surface water is infiltrating and recharging the aquifer under Well #1. Using the acid mine drainage simulant (citric acid), measure and fill graduated cylinder with calculated amount of water needed to recharge the land of Well #1 found in your spreadsheet, being careful not to cross-contaminate

2. Slowly pour out the acid mine drainage water to "make it rain" over the parcel of land.

All Well Owners:
Make predictions about how the acid mine drainage will affect the shared aquifer system. Be sure to address the following questions in your prediction, citing evidence from the simulation, the video, your research, and the evidence below to support your claim.

What effects might the acid mine drainage have on the aquifer system, and the owners of each of the three wells over a period of four months?

Which parcel(s) of land will be affected the most?

How do you think the effects of the acid mine drainage will change over the course of four pumping and recharge cycles?

Some evidence to consider while making your reasoned predictions:

The National Secondary Drinking Water Regulations (NSDWRs) considers safe drinking water to have a pH of 6.5-8.5.

Many plants cannot survive in soils that are too acidic.

Sand is a very porous and permeable sediment.

Month 2: Pumping

1. Communities and farms that use wells #1, #2 and #3 require 90 - 100 ml of safe water each month (60 seconds) to maintain their way of life. Start a timer and pump water for 60 seconds.

2. Record the amount of water pumped from each well in Month 2 in the data table.

3. Measure and record the pumped water's pH level in Month 2 in the data table.

4. Dump the pumped water down the sink after the pH has been recorded.

Months 3-10: Hooray! The Cause Of The Acid Mine Drainage Was Stopped At Its Source!

The source of the acid mine drainage was contained, so recharge water is no longer acidic!

1. Use tap water to fill graduated cylinders with the calculated amount of surface water for recharging the aquifer.

2. Slowly pour water over the assigned parcels of land. Wait 45 seconds.

3. Start a timer for 60 seconds to begin the next "month" and pump water from wells #1, #2 and #3.

4. Record the amount of water pumped from each well in the appropriate month row of the data table.

5. Measure and record the pumped water's pH level in the appropriate month row of the data table.

6. Dump the pumped water down the sink after the pH has been recorded.

7. Repeat steps 1 - 6 until you've completed 10 simulation months of recharge-pumping cycles.

Data Analysis

Create a line-graph depicting the pH levels of all three wells over time.

To create the graph:

1. Place "pH" on the vertical axis, data range from 2 to 9.

2. "Months" should be on the horizontal axis and range from 0 to 10

3. Use a different color to depict each well, and provide a key (Example: Well 1 = red, Well 2 = blue, Well 3 = Green).

Simulation Inferences:

1. What trends or patterns did you notice in the pH data and resulting graph?

2. How did acidity change over time at each well?

3. Why did the acidity of the well water change over time?

4. How might the porosity and permeability of the sediments contribute to observed patterns?

5. What questions do you have as a result of looking at the data and graph?

Visualizing The Plume Through Time

With enough data points, a plume of contaminated groundwater can be monitored over time to determine the size of the region it affects and to predict directions it may flow in the future. In this simulation, there are only three data points for each month so a detailed map of the plume and its movement isn't possible. However, we can visualize how the acidity across the three-pump aquifer system changes over time.

Look at the " Pollution Plume Data Visualization " worksheet. The small diagrams represent a birds-eye view of the shared aquifer model.

1. For each month, write the corresponding pH levels at each well in small writing. (Wells are represented by circles in the diagram.)

2. Using the color scale appropriate for the pH you are using, draw a small swatch of color that represents the pH on top of the numbers you wrote in the previous step.

3. Your final data visualization should be a solid gradient of colors that changes based on the observed pH in well water. To fill-in the blank areas between the color swatches you'll need to make assumptions about the pH in the water between wells that you didn't directly measure. For this model you can assume that the distance halfway between the wells will be the average of the pH in the two wells. For example, if Well #1 has a pH of 4.8 and Well # 2 has a pH of 6.8, we will assume that the pH of the water between the wells will change at equal intervals from 4.8 (dark orange) to 5.0 (yellow) to 6.0 (light green) to 6.8 (darker green very similar to 7.0). The "halfway" point between pH 4.8 and pH 6.8 can be assumed to be the average of Well #1 and Well #2 which would be 5.8.
(4.8+6.8)/2 = 5.8.

4. Use the visualizations to answer the questions on the Pollution Plume Data Visualization Worksheet.

Final Questions

In this simulation, the acid mine drainage came from a long-abandoned mine that has been in disrepair for over 100 years, a scenario that is fairly typical of acid mine pollution events.

1. Who was affected by the AMD in your aquifer system model? How does your simulation compare to the actual effects detailed in the story? Cite specific data from your studies to support your argument.

2. In your group's opinion, who should be responsible for making sure the groundwater in the aquifer is suitable for human consumption? Be sure to support your claim with a well-reasoned explanation.

3. With your group, list and describe at least two ideas that could be used to remediate the contamination in real life. That is, what could be done to clean up the acid mine drainage or protect the aquifer so that the groundwater being pumped is safe for human consumption? Consider searching for examples of successful acid mine remediation.

4. Optional: Plan a remediation simulation for the model using your recommendations from #3, and then implement your remediation plan with your groundwater model.

Next Generation Science Standards

HS-ESS2-2. Analyze geoscience data to make the claim that one change to Earth's surface can create feedbacks that cause changes to other Earth systems.

HS-ESS3-4. Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.

Credits:

Groundwater model, simulation, and student materials by Ryan Hollister
Resource and penny demo written by Ariel Zych
Production: Xochitl Garcia, Ariel Zych
Editing and revisions: Ariel Zych, Brian Soash, Ryan Hollister

Educator's Toolbox

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Build a model aquifer using a plastic shoebox, PVC pipe, and condiment pumps, then use it to model groundwater contamination by acid mine drainage.

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https://www.youtube.com/watch?v=1xLFOQQy7_o

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https://www.youtube.com/watch?v=J5oMwgXNq8s&fbclid=IwAR0OhOulke9AGZPdgkGRe_HjdxurGGetcc7Jt-bK0IiJv35YsI6wPmZQJso&app=desktop

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BabyLegs: a DIY research trawl for monitoring ocean plastic

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https://microplasticsurvey.org/?fbclid=IwAR0Vz7oE3NwAj_VhN702VZ9KMuVXg-VL2mLUy6Mvt4Fpf8jNmikcMz_dNrY

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https://www.youtube.com/watch?v=In1Foq4l43A

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https://www.youtube.com/watch?v=v33CgWJ2TZ0

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BOD (biological oxygen demand) - The water quality indicator

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https://www.youtube.com/watch?v=MmeFcCFvKEU

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How to find the Biochemical Oxygen Demand BOD Using Winkler's Direct Method

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https://patrickrwells.blogspot.com/2017/04/ocean-acidification-inquiry-activity.html

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Ocean Acidification Inquiry Activity (Grades 7-12)

An iceberg covered with gulls in Conception Bay, NL, Canada.

The first lesson I would like to post on my blog is an Ocean Acidification Activity. Ocean Acidification is a serious matter. Each year human combustion activities pump 50 million metric tonnes of carbon dioxide into the atmosphere (Schnoor, 2013). Carbon dioxide in the air dissolves freely into the oceans (Byrne, 2014, p. 5352) and this is creating problems with ocean chemistry (Schnoor, 2013). For the oceans, "the massive amount of CO 2 absorbed, about 1 million tonnes per hour, generates large-scale changes in seawater chemistry that are collectively referred to as anthropogenic ocean acidification" ( Gattuso, Mach, & Morgan, 2013, p. 726). The acidification result from processes that convert carbon dioxide into carbonic acid (Byrne, 2014) and results in pH changes in the ocean (Schnoor, 2014; Schnoor, 2013).
Watch the video!
Not many students are aware of the ocean facts related to this phenomenon:

1. If it were not for the sea's ability to absorb carbon dioxide the planet would likely be much warmer - thank you ocean!

2. Carbon dioxide dissolves into the ocean and forms carbonic acid.

3. The pH of the ocean is currently above pH 8. It was 8.2 but has decreased to 8.1, not acidic but becoming more acidic. Many studies suggest the pH of the ocean is decreasing (by 25% in the past 200 years).

4. The current level of pH of the ocean allows organisms to make shells using calcium carbonate (due to the low solubility of CaCO ₃ above pH 8). A decrease in pH diminishes some species ability to make their shells. Many of these organisms are the bottom of the food chains or base of ecosystem energy pyramids.

5. If the pH of the ocean decreases many organisms will be impacted, and it may change the balance of the ecosystems in the oceans.

6. We are the cause of the problem. However, we are also the solution to this issue (keep it positive, we need students to help our oceans!).

The goal of the lesson is to help students make connections between the physical change in ocean water and the over production of carbon dioxide by burning fossil fuels. The trick to making the lesson "turn the tide" of realization of the human impacts on our planet. I suggest you start with a simple task - examining basic the pH of an ocean water sample and seashells. This will require two sessions, one to conduct activities and a second for evaluation and discussion. It is possible to piece together the events in another order: this is your choice, and I would be interested to hear how it goes (I love changing things up).

Materials Required: 1L of seawater or artificial seawater (see recipe*), 100 or 200 ml beakers, clean drinking straws, safety goggles, seashells (not snail shells and they must be free of allergens), Vinegar, Bleach, LabQuest2 with pH and CO2 probes, or Litmus paper (red and blue) or bromothymol blue solution (there are three different strategies to collect data for pH change).

*If you have no access to seawater you can make a sample with tap water and table salt. A tested recipe is 1 teaspoon NaCl per 200 ml of tap water (this makes a sample of about 30-35 ppt). If you have some limewater you could add 30-40ml to the 200 ml of salt solution. The pH will not be 8 but the water should be alkaline (you may also raise the pH by adding drops of bleach until you get the pH you desire). Once you have your sample prepared and tested, set it aside until required.

Steps of the lesson (steps 1 and 2 may be switched):

1. Break into lab groups and answer an information question related to the carbon cycle. The intention is to start a discussion about the problems of excess carbon dioxide.

2. Introduce a discrepant event and use POE (follow this link for an explanation of POE - https://arbs.nzcer.org.nz/predict-observe-explain-poe).

3. Use the discrepant event to make a connection to the ocean and have student lab groups conduct investigations that relate to the carbon problem.

4. Students report their data to the class. Discuss how they results relate to the problem of CO2 levels and ecological changes on Earth. Class analysis and recommendations.

5. Conduct an extension activity (another POE) and ask students to make recommendations based upon the results of the experiments.

1. Group questions and examining the problem (10 minutes)

Start the class by breaking into lab groups and ask students to think about the carbon cycle. Pass out some seashells (make sure they are clean and dry, if not, students with shellfish allergies may react). My students will have investigated the cycles using the "mini-earth" (that is a later blog) so I remind them of the principles of cycling demonstrated by our previous investigations. Ask the student groups or lab groups one of these questions:

This line of inquiry by lab groups may not lead to the idea of ocean acidification. Students should know they produce carbon dioxide and that it is able to dissolve in water. Next, you need to use some pH indicator magic to hook the students.

2. Discrepant Event (POE) (10 minutes)

Put 100 ml of your seawater sample into a beaker. Add bromothymol blue indicator (it should remain blue if the pH is 8, make sure you test it!). Tell the students what you seawater and then ask the student lab groups "What will happen if I blow bubbles in this beaker of seawater?" Allow them to record answers and predict, then demonstrate the process. As you slowly bubble air through the water the solution, the students will observe it turn blue-green then yellow. Ask the students, what happened and why? Since the class is full of oxygen, could it be oxygen? What else could it be? Nitrogen? In groups, suggest what gas caused this change? You must ask them, what will happen if we leave this beaker overnight? (this solution will turn blue overnight as the CO ₂ dissolves out of solution - you can observe this the next day).

Students may make the connection to an acid being formed. If not you can tell them seawater changed because of the carbon dioxide. When you exhale CO ₂ into water it forms carbonic acid and this acid reduces the pH of the water, making it more acidic. You could explain pH, but I prefer to let them conduct one of two experiments and the need for knowing pH will arise from their investigations.

3. Experiments with Seawater (20-30 minutes)

Ask the lab groups to conduct an experiment and report their findings to the class. There are two experiments: 1. Measuring the pH of seawater as CO ₂ is bubbled through it; 2. Exposing seashells to tap water, an acid, and a base. The experiments are complementary and it is useful to have different lab groups collect observations then pass them on the other groups (using a grouping strategy that has students going to other groups to report their group's results or by posting the results in some manner, such as on the wall again).

Experiment 1 - Bubble experiment: Each lab groups, now called the bubble groups, must obtain a straw, goggles, a beaker, and a pH-measuring device (litmus paper, calibrated pH meter (LabQuest 2 with pH probe) or bromothymol blue indicator). Ask the student to devise a protocol to examine the change in acidity. Let them struggle with the procedure and report the steps to you before they start. They must consider safety and their data must include a baseline reading, time of the bubbling, and have a "bubbling protocol" (good science controls variables to isolate the one of interest - CO ₂ impact on pH). For example, they should take a baseline pH reading then bubble for thirty seconds, then record pH again. They should record the pH every 30 seconds and bubble for about 2-3 minutes (exhaling normally - no need to pass out!). The pH should drop by a whole unit on the pH scale or be noticeable with the Litmus paper. This is a great opportunity for them to examine the pH scale of pH and is an opportunity to explain the logarithmic scale as you travel around visiting the lab groups. Have the groups graph the data, pH versus time (or colour versus time), and prepare to report their results for next day.

While the students conduct this experiment connect the pH probe to the LabQuest2. Run an experiment overnight to graph the pH over 24 hours - acidity will give way to a pH of over 8 once the CO2 gases off!

Experiment 2 - Seashell experiment: This experiment will examine the effect of pH on seashells. For the shell experiment lab groups, now called the shell groups, will use three beakers, three similar sized seashells, seawater solution, vinegar, bleach (diluted to 25%) and a balance for mass determination. Ask the students to determine the protocol for exposing shells to three different liquids; safety is important as they are handling acids and bases. Procedures should involve determining the initial mass of seashells and recording the result (the mass should be ± 0.01g if possible). Have students note the features of the shells (visual and tactile inspection); pictures are advised. The shells should be dropped into the respective solutions and observations documented. Again, circulate around the groups - a gas may be evolved, the solution may get cloudy, reinforce that all these observations are important. Ask the students to consider allowing the experiment to continue overnight (the reaction is not vigorous with a weak acid). If they do, at the beginning of the next class the must rinse the shells off with water, make visual observations, dry then and obtain the mass of each shell. The group must add the data to the prepared table to report their findings to the other groups. The 'bubble groups' could watch the shell groups finish their data collection and this is a time to explain procedures used by the shell groups.

4. Reporting the Findings (Next day, 20 minutes)

The student scientists now need to report their data. It is exciting to start with the results, then open the floor for the students to question each other in terms of procedures, safety considerations and standardization of measuring practices. This activity can be conducted in a smaller, safer environment by matching a 'shell group' with a 'bubble group'. They will describe their data to each other and then clarify if the data was collected in a sound manner with minimal sources of error. Both groups then combine to produce two recommendations to the class based upon their observations. These will be posted on the wall for the whole class to see (counting down time is useful to urge groups to be efficient).

5. Discrepant Event Number 2 (another POE, 20 minutes or more)

Once the two recommendations are posted, have the students gather around and predict what will happen if you drop a seashell in an acid solution (your solution will be a strong acid - all students should "goggle up" before they approach you). They will be expecting small bubbles. Instruct them to watch as you drop a seashell into a strong acid solution (200 ml beaker with 50 ml of 1M HCl works well). This reaction will be vigorous and produce a significant amount of gas (CO ₂ but do not tell them). Ask them: what gas is being produced? How can you prove that? Let them figure it out.

Since the shells are composed of CaCO ₃ this must be CO ₂. Have students suggest answers. Then demonstrate that the gas will extinguish a flame - proof that is CO ₂. Next, comes this big question: What is the connection between acidity, shells dissolving and global warming?
One the students have tried this redo this and connect the CO2 probe to the LabQuest2. The graph produced will be an exponential spike in CO2. If you allow this to run over night the CO2 levels return to normal!

Use this question and all the student recommendations to develop a focus on the problem with ocean acidity. Many school labs do not permit stressful examination of organisms and these experiments take months. However, evidence suggests CO ₂ is the cause of global warming. Have groups must consider the following (thanks, Bill Nye): What if the pH of the ocean decreases and the CO ₂ storage ability of the ocean decreases? How will a warmer ocean store CO ₂? Now you can have a meaningful investigation and discussion - ask the lab groups to reform. The task of the lab groups to use the evidence collected to convince the government we have a significant problem. Write a letter to the Minister of the Environment and express your concerns and use your experimental evidence to support your claims. The letters can be reviewed by the class and if possible, emailed or posted to the Minister of the Environment (federal and provincial).

These experiments generate a lot of discussion and conflict with student conceptions about many things such as - the fragility of the powerful ocean, problems with rising temperatures, and direct connections to their behaviours and our planet's geochemical cycles.

Below are useful Sites to build your knowledge or for student investigations. There are some great videos and the content is grades 7-12 appropriate.

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Ocean Acidification Inquiry Activity (Grades 7-12)

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Ocean Acidification Inquiry Activity (Grades 7-12) An iceberg covered with gulls in Conception Bay, NL, Canada. The first lesson I would like to post on my blog is an Ocean Acidification Activity. Ocean Acidification is a serious matter. Each year human combustion activities pump 50 million metric tonnes of carbon dioxide into the atmosphere (Schnoor, 2013).

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https://leafpacknetwork.org

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PocketMacros features nine orders of aquatic insects, plus other benthic macroinvertebrates commonly used in water quality biomonitoring and environmental education, with 150 taxa total.

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Welcome to the Leaf Pack Network - Leaf Pack Network

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The Leaf Pack Network® is an international network of teachers, students, and citizen monitors investigating their local stream ecosystems. Through the Leaf Pack Experiment, monitors use tree leaves and aquatic insects to determine the health of their stream and to understand its ecology.

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Lincoln index and Simpon's diversity index

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Lincoln index and Simpon's diversity index

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https://www.youtube.com/watch?v=R80LsxKV9uc

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https://www.youtube.com/watch?v=M51AKJqx-7s

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https://www.youtube.com/watch?v=gFRHIb0wDLI

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https://www.youtube.com/watch?v=zHHRmqWuTDo

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Vernier Optical DO Probe - Tech Tips with Vernier

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https://www.youtube.com/watch?v=hQcCRJisz9U&t=78s

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https://www.youtube.com/watch?v=WrmdOHXIN7w&list=PLLeqFNk92vRxOiD9fIfX_Pg4F0OBpyx3w&index=12

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https://app.thepocketlab.com/resources?filters=%5B%22sensor.air%22%5D

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https://app.thepocketlab.com/lab-report/nMpyRcWP0001ud_Y?ro=1&ref=%2Fresources%3Ffilters%3D%255B%2522sensor.air%2522%255D

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https://en.wikipedia.org/wiki/Biosphere_2

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Biosphere 2 is an American Earth system science research facility located in Oracle, Arizona. Its mission is to serve as a center for research, outreach, teaching, and lifelong learning about Earth, its living systems, and its place in the universe. It is a 3.14-acre (1.27-hectare) structure originally built to be an artificial, materially closed ecological system, or vivarium. It remains the largest closed ecological system ever created.

Constructed between 1987 and 1991, Biosphere 2 was originally meant to demonstrate the viability of closed ecological systems to support and maintain human life in outer space as a substitute for Earth's biosphere. It was designed to explore the web of interactions within life systems in a structure with different areas based on various biological biomes. In addition to the several biomes and living quarters for people, there was an agricultural area and work space to study the interactions between humans, farming, technology and the rest of nature as a new kind of laboratory for the study of the global ecology. Its mission was a two-year closure experiment with a crew of eight humans. Long-term it was seen as a precursor to gaining knowledge about the use of closed biospheres in space colonization. As an experimental ecological facility it allowed the study and manipulation of a mini biospheric system without harming Earth's biosphere.

Its seven biome areas were a 1,900-square-meter (20,000 sq ft) rainforest, an 850-square-meter (9,100 sq ft) ocean with a coral reef, a 450-square-meter (4,800 sq ft) mangrove wetlands, a 1,300-square-metre (14,000 sq ft) savannah grassland, a 1,400-square-meter (15,000 sq ft) fog desert, and two anthropogenic biomes: a 2,500-square-meter (27,000 sq ft) agricultural system and a human habitat with living spaces, laboratories and workshops. Below ground was an extensive part of the technical infrastructure. Heating and cooling water circulated through independent piping systems and passive solar input through the glass space frame panels covering most of the facility, and electrical power was supplied into Biosphere 2 from an onsite natural gas power plant.

Biosphere 2 was only used twice for its original intended purposes as a closed-system experiment: once from 1991 to 1993, and the second time from March to September 1994. Both attempts ran into problems including low amounts of food and oxygen, die-offs of many animals and plants included in the experiment (though this was anticipated since the project used a strategy of deliberately "species-packing" anticipating losses as the biomes developed), group dynamic tensions among the resident crew, outside politics, and a power struggle over management and direction of the project. The second closure experiment achieved total food sufficiency and did not require injection of oxygen.

In June 1994, during the middle of the second experiment, the managing company, Space Biosphere Ventures, was dissolved, and the facility was left in limbo. Columbia University assumed management of the facility in 1995 and used it to run experiments until 2003. It then appeared to be in danger of being demolished to make way for housing and retail stores, but was taken over for research by the University of Arizona in 2007. The University of Arizona took full ownership of the structure in 2011. Research continues at the facility while also being a place that is open to the public.

The Biosphere 2 project was launched in 1984 by businessman and billionaire philanthropist Ed Bass and systems ecologist John P. Allen, with Bass providing US$150 million in funding until 1991. Bass and Allen had met in the 1970s at the Synergia Ranch, a counterculture community led by Allen, who advocated Buckminster Fuller's " Spaceship Earth" concept and explored the idea of biospheres as a refuge from disasters such as nuclear war. Several other former members of Synergia Ranch also joined the Biosphere 2 project.

Construction was carried out between 1987 and 1991 by Space Biosphere Ventures, a joint venture whose principal officers were John P. Allen, inventor and executive chairman; Margaret Augustine, CEO; Marie Harding, vice-president of finance; Abigail Alling, vice president of research; Mark Nelson, director of space and environmental applications, William F. Dempster, director of system engineering, and Norberto Alvarez-Romo, vice president of mission control.[citation needed ]

It was named "Biosphere 2" because it was meant to be the second fully self-sufficient biosphere, after the Earth itself ("Biosphere 1").

The glass and spaceframe facility is located in Oracle, Arizona at the base of the Santa Catalina Mountains, about 50 minutes north of Tucson. Its elevation is around 4,000 feet (1,200 m) above sea level.

The above-ground physical structure of Biosphere 2 was made of steel tubing and high-performance glass and steel frames. The frame and glazing materials were designed and made to specification by a firm run by a one-time associate of Buckminster Fuller, Peter Jon Pearce (Pearce Structures, Inc.). The window seals and structures had to be designed to be almost perfectly airtight, such that the air exchange would be extremely low, permitting tracking of subtle changes over time. The patented airtight sealing methods, developed by Pearce and William Dempster, achieved a leak rate of less than 10% per year. Without such tight closure, the slow decline of oxygen which occurred at a rate of less than % per month during the first two-year closure experiment might not have been detected.

During the day, the heat from the sun caused the air inside to expand and during the night it cooled and contracted. To avoid having to deal with the huge forces that maintaining a constant volume would create, the structure had large diaphragms kept in domes called "lungs" or variable volume structures.

Since opening a window was not an option, the structure also required a sophisticated system to regulate temperatures within desired parameters, which varied for the different biomic areas. Though cooling was the largest energy need, heating had to be supplied in the winter and closed loop pipes and air handlers were key parts of the energy system. An energy center on site provided electricity and heated and cooled water, employing natural gas and backup generators, ammonia chillers and water cooling towers.

First mission crew member Mark Nelson measuring soil moisture next to CO2 efflux device in 1993

External videos

Odyssey in Two Biospheres - documentary film with historical footage of the first mission of Biosphere 2, reflections from three of the original mission members, and their life after re-entry into Biosphere 1 (full episode)

The first closed mission lasted from September 26, 1991, to September 26, 1993. The crew were: medical doctor and researcher Roy Walford, Jane Poynter, Taber MacCallum, Mark Nelson, Sally Silverstone, Abigail Alling, Mark Van Thillo, and Linda Leigh.

The agricultural system produced 83% of the total diet, which included crops of bananas, papayas, sweet potatoes, beets, peanuts, lablab and cowpea beans, rice, and wheat. Especially during the first year, the eight inhabitants reported continual hunger. Calculations indicated that Biosphere 2's farm was amongst the highest producing in the world "exceeding by more than five times that of the most efficient agrarian communities of Indonesia, southern China, and Bangladesh".

They consumed the same low-calorie, nutrient-dense diet that Roy Walford had studied in his research on extending lifespan through diet. Medical markers indicated the health of the crew during the two years was excellent. They showed the same improvement in health indices such as lowering of blood cholesterol, blood pressure, enhancement of immune system. They lost an average of 16% of their pre-entry body weight before stabilizing and regaining some weight during their second year. Subsequent studies showed that the biospherians' metabolism became more efficient at extracting nutrients from their food as an adaptation to the low-calorie, high nutrient diet.

Some of the domestic animals that were included in the agricultural area during the first mission included: four African pygmy goats and one billy goat; 35 hens and three roosters (a mix of Indian jungle fowl (Gallus gallus), Japanese silky bantam, and a hybrid of these); two sows and one boar Ossabaw dwarf pigs; and tilapia fish grown in a rice and azolla pond system originating millennia ago in China.

Biosphere 2, viewed from the thornscrub, a transition zone between Savannah and Desert (foreground) and Ocean (background) sections

A strategy of "species-packing" was practiced to ensure that food webs and ecological function could be maintained if some species did not survive. The fog desert area became more chaparral in character due to condensation from the space frame. The savannah was seasonally active; its biomass was cut and stored by the crew as part of their management of carbon dioxide. Rainforest pioneer species grew rapidly, but trees there and in the savannah suffered from etiolation and weakness caused by lack of stress wood, normally created in response to winds in natural conditions. Corals reproduced in the ocean area, and crew helped maintain ocean system health by hand-harvesting algae from the corals, manipulating calcium carbonate and pH levels to prevent the ocean becoming too acidic, and by installing an improved protein skimmer to supplement the algae turf scrubber system originally installed to remove excess nutrients. The mangrove area developed rapidly but with less understory than a typical wetland possibly because of reduced light levels. Nevertheless, it was judged to be a successful analogue to the Everglades area of Florida where the mangroves and marsh plants were collected.

Biosphere 2, because of its small size and buffers, and concentration of organic materials and life, had greater fluctuations and more rapid biogeochemical cycles than are found in Earth's biosphere. Most of the introduced vertebrate species and virtually all of the pollinating insects died, though there was reproduction of plants and animals. Insect pests, like cockroaches, flourished. A globally invasive tramp ant species, Paratrechina longicornis had come to dominate other ant species. The planned ecological succession in the rainforest and strategies to protect the area from harsh incident sunlight and salt aerosols from the ocean worked well, and a surprising amount of the original biodiversity persisted. Biosphere 2 in its early ecological development was likened to an island ecology.

Group dynamics: psychology, conflict, and cooperation

Much of the evidence for isolated human groups comes from psychological studies of scientists overwintering in Antarctic research stations. The study of this phenomenon is " confined environment psychology" ( environmental psychology); according to Jane Poynter, it was known to be a challenge and crews often split into factions.

Before the first closure mission was half over, the group had split into two factions and, according to Poynter, people who had been intimate friends had become implacable enemies, barely on speaking terms. "Appreciation of the value of biosphere interconnectedness and interdependency was appreciated as both an everyday beauty and a challenging reality," Walford later acknowledged, "I don't like some of them, but we were a hell of a team. That was the nature of the factionalism... but despite that, we ran the damn thing and we cooperated totally."

The factions inside the bubble formed from a rift and power struggle between the joint venture partners on how the science should proceed, as biospherics or as specialist ecosystem studies (perceived as reductionist). The faction that included Poynter felt strongly that increasing research should be prioritized over degree of closure. The other faction backed project management and the overall mission objectives. On February 14, a portion of the Scientific Advisory Committee (SAC) resigned. Time magazine wrote: "Now, the veneer of credibility, already bruised by allegations of tamper-prone data, secret food caches and smuggled supplies, has cracked ... the two-year experiment in self-sufficiency is starting to look less like science and more like a $150 million stunt." The SAC was dissolved because it had deviated from its mandate to review and improve scientific research and became involved in advocating management changes. Some SAC members chose to remain as consultants to Biosphere 2. The SAC's recommendations in their report were implemented including a new Director of Research Jack Corliss, allowing import/export of scientific samples and equipment through the facility airlocks to increase research and decrease crew labor, and to generate the lacking formal research program. Some sixty-four projects were included in the research program that Walford and Alling spearheaded developing.

Undoubtedly the reduced oxygen and the calorie-restricted, nutrient-dense diet contributed to low morale. The Alling faction feared that the Poynter group were prepared to go so far as to import food, if it meant making them fitter to carry out research projects. They considered that would be a project failure by definition.

In November 1992, the hungry Biospherians began eating seed stocks that had not been grown inside the Biosphere 2. Poynter made Chris Helms, PR Director for the enterprise, aware of this. She was promptly dismissed by Margret Augustine, CEO of Space Biospheres Ventures, and told to come out of the biosphere. This order was, however, never carried out. Poynter writes that she simply decided to stay put, correctly reasoning that the order could not be enforced without effectively terminating the closure.

Isolated groups tend to attach greater significance to group dynamic and personal emotional fluctuations common in all groups. Some reports from polar station crews exaggerated psychological problems. Although some of the first closure team thought they were depressed, psychological examination of the biospherians showed no depression and fit the explorer/adventurer profile, with both women and men scoring very similarly to astronauts.

Challenges

The fog desert biome of Biosphere 2 in 2005

Among the problems and miscalculations encountered in the first mission were unanticipated condensation making the "desert" too wet, population explosions of greenhouse ants and cockroaches, morning glories overgrowing the rainforest area blocking out other plants, and less sunlight (40-50% of outside light) entering the facility than originally anticipated. Biospherians intervened to control invasive plants when needed to preserve biodiversity, functioning as " keystone predators". In addition, construction itself was a challenge; for example, it was difficult to manipulate the bodies of water to have waves and tidal changes.

There was controversy when the public learned that the project had allowed an injured member to leave and return, carrying new material inside. The team claimed the only new supplies brought in were plastic bags, but others accused them of bringing food and other items. More criticism was raised when it was learned that, likewise, the project injected oxygen in January 1993 to make up for a failure in the balance of the system that resulted in the amount of oxygen steadily declining. Some thought that these criticisms ignored that Biosphere 2 was an experiment where the unexpected would occur, adding to knowledge of how complex ecologies develop and interact, not a demonstration where everything was known in advance. H. T. Odum noted: "The management process during 1992-1993 using data to develop theory, test it with simulation, and apply corrective actions was in the best scientific tradition. Yet some journalists crucified the management in the public press, treating the project as if it was an Olympic contest to see how much could be done without opening the doors".

The oxygen inside the facility, which began at 20.9%, fell at a steady pace and after 16 months was down to 14.5%. This is equivalent to the oxygen availability at an elevation of 4,080 metres (13,390 ft). Since some biospherians were starting to have symptoms like sleep apnea and fatigue, Walford and the medical team decided to boost oxygen with injections in January and August 1993. The oxygen decline and minimal response of the crew indicated that changes in air pressure are what trigger human adaptation responses. These studies enhanced the biomedical research program.

Managing CO ₂ levels was a particular challenge. Daily fluctuation of carbon dioxide dynamics was typically 600 ppm because of the strong drawdown during sunlight hours by plant photosynthesis, followed by a similar rise during the nighttime when system respiration dominated. As expected, there was also a strong seasonal signature to CO ₂ levels, with wintertime levels as high as 4,000-4,500 ppm and summertime levels near 1,000 ppm.

The crew worked to manage the CO ₂ by occasionally turning on a CO₂ scrubber, after realizing that activating and de-activating the desert and savannah through control of irrigation water, cutting and storing biomass to sequester carbon, and utilizing all potential planting areas with fast-growing species to increase system photosynthesis, wouldn't be enough to sustain human life. In November 1991, investigative reporting in The Village Voice alleged that the crew had secretly installed the CO ₂ scrubber device, and claimed that this violated Biosphere 2's advertised goal of recycling all materials naturally. Others pointed out there was nothing secret about the carbon dioxide device and it constituted another technical system augmenting ecological processes. The carbon precipitator could reverse the chemical reactions and thus release the stored carbon dioxide in later years when the facility might need additional carbon.

The soils were selected to have enough carbon to provide for the plants of the ecosystems to grow from infancy to maturity, a plant mass increase calculated to be 20 short tons (18,000 kg). The release rate of that soil carbon as carbon dioxide by respiration of soil microbes was an unknown that the Biosphere 2 experiment was designed to reveal. Subsequent research showed that Biosphere 2's farm soils had reached a more stable ratio of carbon and nitrogen, lowering the rate of CO ₂ release, by 1998.

The respiration rate was faster than the photosynthesis (possibly in part due to relatively low light penetration through the glazed structure and the fact that Biosphere 2 started with a small but rapidly increasing plant biomass) resulting in a slow decrease of oxygen. A mystery accompanied the oxygen decline: the corresponding increase in carbon dioxide did not appear. This concealed the underlying process until an investigation by Jeff Severinghaus and Wallace Broecker of Columbia University's Lamont-Doherty Earth Observatory using isotopic analysis showed that carbon dioxide was reacting with exposed concrete inside Biosphere 2 to form calcium carbonate in a process called carbonatation, thereby sequestering both carbon and oxygen.

After Biosphere 2's first mission, extensive research and system improvements were undertaken, including sealing concrete to prevent the uptake of carbon dioxide. The second mission began on March 6, 1994, with an announced run of ten months. The crew was Norberto Alvarez-Romo (Capt.), John Druitt, Matt Finn, Pascale Maslin, Charlotte Godfrey, Rodrigo Romo and Tilak Mahato. The second crew achieved complete sufficiency in food production.

On April 1, 1994, a severe dispute within the management team led to the ousting of the on-site management by federal marshals serving a restraining order, and financier Ed Bass hired Steve Bannon, then-manager of the Bannon & Co. investment banking team from Beverly Hills, California, to run Space Biospheres Ventures. The project was put into receivership and an outside management team was installed for the receiver to turn around the floundering project. The reason for the dispute was threefold. Mismanagement of the mission had caused terrible publicity, financial mismanagement and lack of research. People[who? ] alleged gross financial mismanagement of the project, leading to a loss of $25 million in fiscal year 1992. Some crew members and staff were concerned about Bannon, who had previously investigated cost overruns at the site; two former Biosphere 2 crew members flew back to Arizona to protest the hire and broke into the compound to warn the crew members that Bannon and the new management would jeopardize their safety.

At 3 a.m. on April 5, 1994, Abigail Alling and Mark Van Thillo, members of the first crew, allegedly vandalized the project from outside, opening one double-airlock door and three single door emergency exits, leaving them open for about 15 minutes. Five panes of glass were also broken. Alling later told the Chicago Tribune that she "considered the Biosphere to be in an emergency state ... In no way was it sabotage. It was my responsibility." About 10% of the Biosphere's air was exchanged with the outside during this time, according to systems analyst Donella Meadows, who received a communication from Alling saying that she and Van Thillo judged it their ethical duty to give those inside the choice of continuing with the drastically changed human experiment or leaving, as they didn't know what the crew had been told of the new situation. "On April 1, 1994, at approximately 10 AM ... limousines arrived on the biosphere site ... with two investment bankers hired by Mr. Bass ... They arrived with a temporary restraining order to take over direct control of the project ... With them were 6-8 police officers hired by the Bass organization ... They immediately changed locks on the offices ... All communication systems were changed (telephone and access codes), and [we] were prevented from receiving any data regarding safety, operations, and research of Biosphere 2." Alling emphasized several times in her letter that the "bankers" who suddenly took over "knew nothing technically or scientifically, and little about the biospherian crew".

Four days later, the captain Norberto Alvarez-Romo (by then married to Biosphere 2 chief executive Margaret Augustine) precipitously left the Biosphere for a "family emergency" after his wife's suspension. He was replaced by Bernd Zabel, who had been nominated as captain of the first mission but who was replaced at the last minute. Two months later, Matt Smith replaced Matt Finn.[citation needed ]

The ownership and management company Space Biospheres Ventures was dissolved on June 1, 1994. This left the scientific and business management of the mission to the interim turnaround team, who had been contracted by the financial partner, Decisions Investment Co.

Mission 2 was ended prematurely on September 6, 1994. No further total system science has emerged from Biosphere 2 as the facility was changed by Columbia University from a closed ecological system to a "flow-through" system where CO ₂ could be manipulated at desired levels.

Steve Bannon left Biosphere 2 after two years, but his departure was marked by an "abuse of process" civil lawsuit filed against Space Biosphere Ventures by the former crew members who had broken in. Leading managers of Biosphere 2 from the original founding group stated both abusive behaviour by Bannon and others, and that the bankers' actual goal was to destroy the experiment. During a 1996 trial, Bannon testified that he had called one of the plaintiffs, Abigail Alling, a "self-centered, deluded young woman" and a "bimbo". He also testified that when the woman submitted a five-page complaint outlining safety problems at the site, he promised to shove the complaint "down her throat". Bannon attributed this to "hard feelings and broken dreams". At the end of the trial, the court ruled in favor of the plaintiffs and ordered Space Biosphere Ventures to pay them $600,000.

A special issue of the Ecological Engineering journal edited by Marino and Howard T. Odum and published in 1999 as "Biosphere 2: Research Past and Present" represents the most comprehensive assemblage of collected papers and findings from Biosphere 2. The papers range from calibrated models that describe the system metabolism, hydrologic balance, and heat and humidity, to papers that describe rainforest, mangrove, ocean, and agronomic system development in this carbon dioxide-rich environment. Though several dissertations and many scientific papers used data from the early closure experiments at Biosphere 2, much of the original data has never been analyzed and is unavailable or lost, perhaps due to scientific politics and in-fighting.

The historian of science Rebecca Redier has claimed that because Biosphere 2's creators were perceived as outsiders to academic science, the project was scrutinized but poorly understood in the media, and that this scrutiny ceased after Columbia University assumed management, because it was assumed they were "proper" scientists.

Praise and criticism

One view of Biosphere 2 was that it was "the most exciting scientific project to be undertaken in the United States since President John F. Kennedy launched us toward the moon". Others called it " New Age drivel masquerading as science". John Allen and Roy Walford did have mainstream credentials. John Allen held a degree in Metallurgical-Mining Engineering from the Colorado School of Mines, and an MBA from the Harvard Business School. Roy Walford received his doctorate of medicine from the University of Chicago and taught at UCLA as a Professor of Pathology for 35 years. Mark Nelson obtained his Ph.D. in 1998 under Professor H.T. Odum in ecological engineering further developing the constructed wetlands used to treat and recycle sewage in Biosphere 2, to coral reef protection along the Yucatán coast where the corals were collected. Linda Leigh obtained her PhD with a dissertation on biodiversity and the Biosphere 2 rainforest working with Odum. Abigail Alling, Mark van Thillo and Sally Silverstone helped start the Biosphere Foundation where they worked on coral reef and marine conservation and sustainable agricultural systems. Jane Poynter and Taber MacCallum co-founded Paragon Space Development Corporation which has studied the first mini-closed system and the first full animal life cycle in space and assisted in setting world records in high altitude descents.

Questioning the credentials of the participants (despite the contribution in the preparation phase of Biosphere 2 of worldwide top-level scientists and among others the Russian Academy of Sciences), Marc Cooper wrote that "the group that built, conceived, and directs the Biosphere project is not a group of high-tech researchers on the cutting edge of science but a clique of recycled theater performers that evolved out of an authoritarian-and decidedly non-scientific-personality cult". He was referring to the Synergia Ranch in New Mexico, where indeed many of the Biospherians did practice theater under John Allen's leadership, and began to develop the ideas behind Biosphere 2. They also founded the Institute of Ecotechnics.

One of their own scientific consultants was earlier critical. Ghillean Prance, director of the Royal Botanical Gardens in Kew, designed the rainforest biome inside the Biosphere. Although he later changed his opinion, acknowledging the unique scope of this experiment and contributed to its success as a consultant, in a 1983 interview (8 years before the start of the experiment), Prance said, "I was attracted to the Institute of Ecotechnics because funds for research were being cut and the institute seemed to have a lot of money which it was willing to spend freely. Along with others, I was ill-used. Their interest in science is not genuine. They seem to have some sort of secret agenda, they seem to be guided by some sort of religious or philosophical system." Prance went on in the 1991 newspaper interview to say "they are visionaries ... And maybe to fulfill their vision they have become somewhat cultlike. But they are not a cult, per se ... I am interested in ecological restoration systems. And I think all sorts of scientific things can come of this experiment, far beyond the space goal ... When they came to me with this new project, they seemed so well organized, so inspired, I simply decided to forget the past. You shouldn't hold their past against them."

Poynter in her memoir rebuts the critique that because some of the creative team of Biosphere 2 were not credentialed scientists, the results of the endeavor are invalid. "Some reporters hurled accusations that we were unscientific. Apparently because many of the SBV managers were not themselves degreed scientists, this called into question the entire validity of the project, even though some of the world's best scientists were working vigorously on the project's design and operation. The critique was not fair. Since leaving Biosphere 2, I have run a small business for ten years that sent experiments on the shuttle and to the space station, and is designing life support systems for the replacement shuttle and future moon base. I do not have a degree, not even an MBA from Harvard, as John [Allen] had. I hire scientists and top engineers. Our company's credibility is not called into question because of my credentials: we are judged on the quality of our work". H.T. Odum noted that mavericks and outsiders have often contributed to the development of science: "The original management of Biosphere 2 was regarded by many scientists as untrained for lack of scientific degrees, even though they had engaged in a preparatory study program for a decade, interacting with the international community of scientists including the Russians involved with closed systems. The history of science has many examples where people of atypical background open science in new directions, in this case implementing mesocosm organization and ecological engineering with fresh hypotheses".

In its report of August 1992, the Biosphere 2 Science Advisory Committee, chaired by Tom Lovejoy of the Smithsonian Institution, reported: "The committee is in agreement that the conception and construction of Biosphere 2 were acts of vision and courage. The scale of Biosphere 2 is unique and Biosphere 2 is already providing unexpected scientific results not possible through other means (notably the documented, unexpected decline in atmospheric oxygen levels.) Biosphere 2 will make important scientific contributions in the fields of biogeochemical cycling, the ecology of closed ecological systems, and restoration ecology." Columbia University assembled outside scientists to evaluate the potential of the facility after they took over management, and concluded the following: "A group of world-class scientists got together and decided the Biosphere 2 facility is an exceptional laboratory for addressing critical questions relative to the future of Earth and its environment."

In December 1995, the Biosphere 2 owners transferred management to Columbia University of New York City. Columbia ran Biosphere 2 as a research site and campus until 2003. Subsequently, management reverted to the owners.

In 1996, Columbia University changed the virtually airtight, materially closed structure designed for closed system research, to a "flow-through" system, and halted closed system research. They manipulated carbon dioxide levels for global warming research, and injected desired amounts of carbon dioxide, venting as needed. During Columbia's tenure, students from Columbia and other colleges and universities would often spend one semester at the site.

Research during Columbia's tenure demonstrated the devastating impacts on coral reefs from elevated atmospheric CO ₂ and acidification that will result from continued global climate change. Frank Press, former president of the National Academy of Sciences, described these interactions between atmosphere and ocean, taking advantage of the highly controllable ocean mesocosm of Biosphere 2, as the "first unequivocal experimental confirmation of the human impact on the planet".

Studies in Biosphere 2's terrestrial biomes showed that a saturation point was reached with elevated CO ₂ beyond which they are unable to uptake more. The studies' authors noted that the striking differences between the Biosphere 2 rainforest and desert biomes in their whole system responses "illustrates the importance of large-scale experimental research in the study of complex global change issues".

In January 2005, Decisions Investments Corporation, owner of Biosphere 2, announced that the project's 1,600-acre (650 ha) campus was for sale. They preferred a research use to be found for the complex but were not excluding buyers with different intentions, such as big universities, churches, resorts, and spas. In June 2007, the site was sold for $50 million to CDO Ranching & Development, L.P. 1,500 houses and a resort hotel were planned, but the main structure was still to be available for research and educational use.

Inside Biosphere 2 in 2015 managed by the University of Arizona

On June 26, 2007, the University of Arizona announced it would take over research at the Biosphere 2. The announcement ended fears that the structure would be demolished. University officials said private gifts and grants enabled them to cover research and operating costs for three years with the possibility of extending funding for ten years. It was extended for ten years, and engaged in research projects including research into the terrestrial water cycle and how it relates to ecology, atmospheric science, soil geochemistry, and climate change. One of these gifts in 2009 included 470 photovoltaic solar panels added to the site. In June 2011, the university announced that it would assume full ownership of Biosphere 2, effective July 1.

CDO Ranching & Development donated the land, Biosphere buildings and several other support and administrative buildings. In 2011, the Philecology Foundation (a nonprofit research foundation founded by Ed Bass) pledged US$20 million for the ongoing science and operations. In 2017, Ed Bass donated another $30 million to the University of Arizona in support of Biosphere 2, endowing two academic positions and setting up the "Philecology Biospheric Research Endowment Fund".

Science camps are also held on the premises. These have included a week-long 'space camp' for university undergraduates, and overnight camps for school students. In 2011 it was reported that there were an average of 100,000 visitors per year visiting the Biosphere 2 campus.

There are many small-scale research projects at Biosphere 2, as well as several large-scale research projects including:

the Landscape Evolution Observatory (LEO), a project which uses 1,800 sensors to monitor millions of pounds of abiotic volcanic rock to track how this nonliving soil slowly develops over several years into a rich soil which is able to support microbial and vascular plant life. Structurally, this involved building three large steel-framed "hillsides" inside the pre-existing domes as the world's largest weighing lysimeter, with design and implementation construction constrained by the limited accessibility into the existing structure.

the Lunar Greenhouse, a second prototype of the Controlled Environment Agriculture Center which seeks to understand how to grow vegetables on the Moon or Mars by developing a bioregenerative life support system which recycles and purifies water through plant transpiration.

a vertical farming project to be built in Biosphere 2's west lung, in collaboration with the private company Civic Farms, in an effort to develop an indoor plant growth cycle with LED lamps configured to specific wavelengths aimed at increasing water efficiency, producing zero farm runoff, with no pests or pesticides, and zero effect from external weather conditions.

Bibliography

Biosphere 2 Official YouTube Channel

Biosphere 2: Story of the Original Design and Building told by Project CoFounders (Video)

"Biosphere 2: Why an Eccentric Ecological Experiment Still Matters 25 Years Later" -- a forum featuring Linda Leigh, Peder Anker, Dana Fritz, Lisa Ruth Rand, and Shawn Rosenheim

Biosphere 2 Astronomical Observatory Illustrated history of its founding, operations, closing under Columbia University rule, and disposition with image galleries of its construction in 1999 and removal in 2008.

New York Times video: "Biosphere 2: An American Space Odyssey" June 10, 2013

Biosphere 2: Our World - a film made during 1st Biosphere mission by Mark Van Thillo, one of the crew on YouTube

Mark Nelson discusses life in Biosphere 2 (Video)

Life in Biosphere 2 - reflections of living in Biosphere 2 by first mission crew member Jane Poynter (TEDxUSC, full episode).

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Biosphere 2 is an American Earth system science research facility located in Oracle, Arizona. Its mission is to serve as a center for research, outreach, teaching, and lifelong learning about Earth, its living systems, and its place in the universe. It is a 3.14-acre (1.27-hectare) structure originally built to be an artificial, materially closed ecological system, or vivarium.

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https://www.bottlebiology.org

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Bottle Biology, an instructional materials development program, was funded by a grant from the National Science Foundation administered by the University of Wisconsin-Madison.

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Ecological resilience and how to measure

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Ecological resilience and how to measure

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https://iopscience.iop.org/article/10.1088/1748-9326/ac5767

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http://www.footprintcalculator.org/home/en

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How many planets does it take to sustain your lifestyle?

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What is your Ecological Footprint? How many planets does it take to support your lifestyle? Take this free quiz to find out!

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https://sdgs.un.org/goals

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Rice and duck farming (circular ecosystem)

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Rice and duck farming (circular ecosystem)

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https://www.youtube.com/watch?v=HWrG2xQiq-4

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Integrated Rice Duck Farming | Grow Rice & Ducks Together

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https://www.sciencefriday.com/educational-resources/how-can-we-clean-up-an-oil-spill/

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Do you want to try cleaning up an oil spill yourself? This experiment will help you understand why it is such a difficult task. All of the tools you will need are environmentally friendly and easy to find.
See the Teacher and Student Guides from AACT

Objectives

By the end of this lesson, students should be able to:

determine which sorbents best absorb oil from fresh and salt water.

make careful observations.

draw conclusions based on their observations.

Safety Notes

Always wear safety goggles when working with chemicals in a lab setting.

Students should wash their hands thoroughly before leaving the lab.

When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals.

Materials

one 28-cm x 19-cm x 4-cm clear glass baking dish (or equivalent)

water

blue food coloring

12 Tbsp vegetable oil

8 Tbsp pure cocoa powder

sea salt (only use table salt if sea salt is not available)

a tablespoon

a teaspoon

5 wooden stirring rods

a coffee mug

sorbents (paper towel, cotton balls, rag, string, nylon pot scrubber, sponge, Styrofoam cup, garden peat moss)

1 squirt of liquid dishwashing detergent

tweezers or tongs

bird feathers (available at some hobby stores)

5 petri dishes

dropper

fine-, medium-, and coarse-grained sand

potting soil

printed student data sheet

Student activity guide from AACT

Procedure

To prepare the fresh water:

1. Fill baking dish with cold tap water within one cm of rim.

2. Add five-six drops of food dye.

3. Mix dye and water with a stirring rod. Let solution settle.

4. Record your observations in Table 1 on the student data sheet.

To simulate the ocean water:

1. Fill baking dish with cold water within 1 cm of rim.

2. Add 8 teaspoons of salt slowly and stir until dissolved.
(If you have a hygrometer, keep adding salt until you reach a salinity of 1.024 - 1.026.)

3. Add five to six drops of food dye.

4. Mix dye and "ocean water" with a stirring rod.

5. Record your observations in Table 1 on the student data sheet.

1. Place 3 Tbsp. of vegetable oil in mug.

2. Add 2 Tbsp. of cocoa powder.

3. Mix cocoa powder and oil thoroughly with a paddle pop stick.

To contaminate each fresh water and ocean water container:

1. Very slowly pour simulated crude oil from a height of 1 cm onto the top of the fresh water dish. If you pour the oil too quickly, the experiment won't work.

2. What happened to the oil when you dropped it on the fresh water? Did it sink? Float? Mix in?

3. Wait 3 minutes. Record your observations in Table 1 on the student data sheet.

4. Repeat steps 1-3 with ocean water.

1. Place a small sorbent sample into the center top of the contaminated fresh water.

2. Record your observations in Table 1. Include all of the following information:
a. How much oil did the sorbent clean up? How quickly?
b. Does the sorbent pick up water too? If so, how can you tell?
c. Does the sorbent sink or float?
d. What is the condition of the contaminated sorbent?

3. Remove sorbent with tweezers or tongs.

4. Repeat step one with other sorbent samples, recording your observations in Table 1 on the student data sheet.

5. Clean out contaminated fresh water.

6. Prepare new contaminated fresh water following the same procedure as before.

7. Add detergent to the oil-contaminated fresh water.

8. What happened when the detergent was added to the contaminated water?

9. Where would the oil go in "real" fresh water after a dispersant (like the dishwashing detergent) is used?

10. How clean is the fresh water now that it has dishwashing liquid in it?

11. Repeat steps 1-7 with ocean water and compare the results with those for fresh water.

To determine how oil affects feathers:

1. Dip feather into oil-contaminated fresh water.
a. What happens when a feather gets oil on it?
b. How might an oiled feather affect a bird?

2. Repeat the steps above, substituting ocean water for the fresh water.

To determine how oil affects soil:

1. Use five plastic petri dishes.

2. Fill one petri dish with fine-grained sand.

3. Fill one petri dish with medium-grained sand.

4. Fill one petri dish with coarse-grained sand.

5. Fill one petri dish with "mud" created by adding enough water to potting soil to create a paste.

6. Fill one petri dish with dry potting soil.

7. Place three droppers full of oil onto each the petri dishes.

8. Record observations each time the oil is added to the different soil substrates in Table 2 on the student data sheet.

Analysis

Based on your observations recorded above, answer the following questions.

How is fresh water/ocean different from tap water?

How would you pick up the oil-contaminated material in a "real" oil spill in fresh water/the ocean?

How would you dispose of the oil-contaminated material in a real oil spill?

Of the sorbents you tested, which one worked the fastest? The best?

What other materials could you use as sorbents?

Are the results of the experiment different when you use fresh water instead of an ocean?

Which soil absorbs the most oil?

Which soil repels the most oil?

Which soil would be the easiest to clean?

Which soil would be the hardest to clean?

The views expressed are those of the author and are not necessarily those of Science Friday.

Featured image of Oil Slick Close Up from Shutterstock.

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Students do an activity to simulate an oil spill and test different materials' abilities to "clean" the oil spill.

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https://www.worldometers.info/world-population/

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World Population: Past, Present, and Future

(move and expand the bar at the bottom of the chart to navigate through time)

The chart above illustrates how world population has changed throughout history. View the full tabulated data.

At the dawn of agriculture, about 8000 B.C., the population of the world was approximately 5 million. Over the 8,000-year period up to 1 A.D. it grew to 200 million (some estimate 300 million or even 600, suggesting how imprecise population estimates of early historical periods can be), with a growth rate of under 0.05% per year.

A tremendous change occurred with the industrial revolution: whereas it had taken all of human history until around 1800 for world population to reach one billion, the second billion was achieved in only 130 years (1930), the third billion in 30 years (1960), the fourth billion in 15 years (1974), and the fifth billion in only 13 years (1987).

During the 20th century alone, the population in the world has grown from 1.65 billion to 6 billion.

In 1970, there were roughly half as many people in the world as there are now.

Because of declining growth rates, it will now take over 200 years to double again.

Wonder how big was the world's population when you were born?
Check out this simple wizard or this more elaborated one to find out.

Growth Rate

Population in the world is growing at a rate of around 0.91% per year in 2024 (up from 0.88% in 2023, and down from 0.98% in 2020, and 1.06% in 2019). The current population increase is estimated at around 73 million people per year.

Annual growth rate reached its peak in the late 1960s, when it was at around 2%. The rate of increase has nearly halved since then, and will continue to decline in the coming years.

World population will therefore continue to grow in the 21st century, but at a much slower rate compared to the recent past. World population has doubled (100% increase) in 40 years from 1959 (3 billion) to 1999 (6 billion). It is now estimated that it will increase by 50% in the subsequent 40 years, to reach 9 billion by 2037.

The latest world population projections indicate that world population will reach 10 billion persons in the year 2057 and 10.4 billion in 2100.

World Population (2024 and historical)
View the complete population historical table
World Population Forecast (2025-2050)
View population projections for all years (up to 2100)
World Population Milestones

10 Billion (2058)

The United Nations projects world population will reach 10 billion in the year 2058.

9 Billion (2037)

World population is expected to reach 9 billion in the year 2037.

8.1 Billion (current)

The current world population is 8,109,479,367 as of Thursday, May 16, 2024 according to the most recent United Nations estimates elaborated by Worldometer. The term "World Population" refers to the human population (the total number of humans currently living) of the world.

8 Billion (2022)

World population has reached 8 billion people on November 15, 2022 according to the United Nations. The U.S. Census Bureau International Database (IDB) estimates instead that the world population hit 8 billion on September 26, 2023. In their note, they added: " Emphasis on the word estimates. There are many sources of uncertainty in estimating the global population, and it's unlikely this population milestone was reached on that exact date" [ source]

7 Billion (2010)

According to the latest revision by the United Nations (released in 2022), world population reached 7 Billion in late 2010 (after being previously estimated as occurring on October 31, 2011). The U.S. Census Bureau made a different estimate, for which the 7 billion mark was reached on March 12, 2012.

6 Billion (1998)

According to the latest revision by the United Nations (released in 2022), the 6 billion figure was reached towards the end of 1998 (this was previously estimated as occurring on October 12, 1999, celebrated as the Day of 6 Billion). According to the U.S. Census Bureau instead, the six billion milestone was reached on July 22, 1999, at about 3:49 AM GMT. Yet, according to the U.S. Census Bureau, the date and time of when 6 billion was reached will probably change because the already uncertain estimates are constantly being updated.

Previous Milestones

Summary Table

1 - 1804 ( 1803 years): 0.2 to 1 bil.

1804 - 2022 ( 218 years): from 1 billion to 8 billion

World Population by Region

World Population Density (people/km²)

Population density map of the world showing not only countries but also many subdivisions (regions, states, provinces). See also: World Map

Courtesy of
Junuxx at en.wikipedia [ CC-BY-SA-3.0 or GFDL], via Wikimedia Commons

World Population by Religion

According to a recent study (based on the 2010 world population of 6.9 billion) by The Pew Forum, there are:

2,173,180,000 Christians (31% of world population), of which 50% are Catholic, 37% Protestant, 12% Orthodox, and 1% other.

1,598,510,000 Muslims (23%), of which 87-90% are Sunnis, 10-13% Shia.

1,126,500,000 No Religion affiliation (16%): atheists, agnostics and people who do not identify with any particular religion. One-in-five people (20%) in the United States are religiously unaffiliated.

1,033,080,000 Hindus (15%), the overwhelming majority (94%) of which live in India.

487,540,000 Buddhists (7%), of which half live in China.

405,120,000 Folk Religionists (6%): faiths that are closely associated with a particular group of people, ethnicity or tribe.

58,110,000 Other Religions (1%): Baha'i faith, Taoism, Jainism, Shintoism, Sikhism, Tenrikyo, Wicca, Zoroastrianism and many others.

13,850,000 Jews (0.2%), four-fifths of which live in two countries: United States (41%) and Israel (41%).

World Population by Country

How many people have ever lived on earth?

It was written during the 1970s that 75% of the people who had ever been born were alive at that moment. This was false.

Assuming that we start counting from about 50,000 B.C., the time when modern Homo sapiens appeared on the earth (and not from 700,000 B.C. when the ancestors of Homo sapiens appeared, or several million years ago when hominids were present), taking into account that all population data are a rough estimate, and assuming a constant growth rate applied to each period up to modern times, it has been estimated that a total of approximately 106 billion people have been born since the dawn of the human species, making the population currently alive roughly 6% of all people who have ever lived on planet Earth.

Others have estimated the number of human beings who have ever lived to be anywhere from 45 billion to 125 billion, with most estimates falling into the range of 90 to 110 billion humans.

World Population clock: sources and methodology

The world population counter displayed on Worldometer takes into consideration data from two major sources: the United Nations and the U.S. Census Bureau.

1. The United Nations Population Division of the Department of Economic and Social Affairs every two years calculates, updates, and publishes estimates of total population in its World Population Prospects series. These population estimates and projections provide the standard and consistent set of population figures that are used throughout the United Nations system.

The World Population Prospect: the 2022 Revision provides the most recent data available (released in July of 2022). Estimates and projected world population and country specific populations are given from 1950 through 2100 and are released every two years. Worldometer, as it is common practice, utilizes the medium fertility estimates.

Data underlying the population estimates are national and sub national census data and data on births, deaths, and migrants available from national sources and publications, as well as from questionnaires. For all countries, census and registration data are evaluated and, if necessary, adjusted for incompleteness by the Population Division as part of its preparations of the official United Nations population estimates and projections.

2. The International Programs Center at the U.S. Census Bureau, Population Division also develops estimates and projections based on analysis of available data (based on census, survey, and administrative information) on population, fertility, mortality, and migration for each country or area of the world. According to the U.S. Census Bureau, world population reached 7 billion on March 12, 2012.

For most countries adjustment of the data is necessary to correct for errors, omissions, and inconsistencies in the data. Finally, since most recent data for a single country is often two years old on average, the current world population figure is necessarily a projection of past data based on assumed trends. As new data become available, assumptions and data are reevaluated and past conclusions and current figures may be modified.

For information about how these estimates and projections are made by the U.S. Census Bureau, see the Population Estimates and Projections Methodology.

Why Worldometer's Population Clock is the most accurate

The above world population clock is based on the latest estimates released in July of 2022 by the United Nations. It will show the same number wherever you are in the world and whatever time you set on your PC.

Visitors around the world visiting a PC clock based counter, instead, will see different numbers depending on where they are located. This is the case with other world population clocks - such as the one hosted on a United Nations website, reaching 8 billion in 24 different instances (one per hour) on November 15, 2022, when each local time zone reached 12:10:08. Similarly, in 2011, the clocks on a UN website and on National Geographic - showed 7 billion whenever the visitor's locally set PC clocks reached 4:21:10 AM on October 31, 2011.

Obviously, the UN data is based on estimates and can't be 100% accurate, so in all honesty nobody can possibly say with any degree of certainty on which day world population reached 7 billion (or any other exact number), let alone at what time. But once an estimate is made (based on the best data and analysis available), the world population clock should be showing the same number at any given time anywhere around the world.

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World Population Clock: 8.1 Billion People (LIVE, 2024) - Worldometer

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How many people are there in the world? World population has reached 8 billion on November 15, 2022 according to the United Nations. World population live counter with data sheets, graphs, maps, and census data regarding the current, historical, and future world population figures, estimates, growth rates, densities and demographics

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https://www.youtube.com/watch?v=QTV3XFHzvT4

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Barnacle competition lab (to inspire competition investigations)

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Barnacle competition lab (to inspire competition investigations)

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http://virtualbiologylab.org/ModelsHTML5/BarnacleCompetition/BarnacleCompetitionModel.html

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https://www.youtube.com/watch?v=wGfOoRrICto

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Ecological Pyramids | Ecology & Environment | Biology | FuseSchool