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RGS Student Guide to the Independent Investigation
RGS Student Guide to the Independent Investigation
Checklist for candidates
Checklist for candidates
Use this to check you have included everything you need in your independent investigation.
How to write up your NEA
How to write up your NEA
A brief overview of the how to go about writing up your NEA (by a very respected examiner)
Writing up your NEA (2)
Writing up your NEA (2)
Another, more detailed guide to write up, this time by another teacher, teaching the course.
Articles for secondary data sources
Articles for secondary data sources
These could be useful places to source information for the theory section of your independent investigation.
FSC Webinar information
FSC Webinar information
Statistical tests
Statistical tests
Not sure which one to use? Not sure how to conduct it? Have a look at the website below.
RGS website to help with specific sections.
RGS website to help with specific sections.
Ethical guidance
Ethical guidance
Mrs Starkey uses this for psychology- and it is useful starting point for the ethics of fieldwork
Statistics- the basics covered
Statistics- the basics covered
This is a fab intro to a range of ideas for the NEA.
 
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 Extra reading- Geofiles etc
Hazards topic
Hazards topic
Glaciation topic
Glaciation topic
Reimagining glaciers
Reimagining glaciers
 
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 The future
Considering taking geography further?
Considering taking geography further?
Its not just about being a geography teacher!
Human Case Studies -
 Human Case Studies - Tim
 
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 Year 13 Checklists for PPEs
Glacial Environments
Glacial Environments
Use this to make sure that you revise all the necessary content.
Hazards
Hazards
What do you know?
 
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 OLD specification papers and mark schemes- Hazards questions
June 2016 QP
June 2016 QP
June 2016 MS
June 2016 MS
June 2014 QP
June 2014 QP
June 2014 MS
June 2014 MS
 
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 OLD specification papers and mark schemes- Glaciation questions
June 2013 QP
June 2013 QP
June 2013 MS
June 2013 MS
June 2012 QP
June 2012 QP
June 2012 MS
June 2012 MS
 
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Get to grips with the specification content, what you are required to know and how you will be assessed. 

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Get to grips with the specification content, what you are required to know and how you will be assessed. 

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A Level Geography at Pershore  High School 

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A Level Geography at Pershore  High School 

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Electronic version of expectations and specification

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Phrase bank to help get you started with essay writing.

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Phrase bank to help get you started with essay writing.

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Exam board Key terms and Command words - get to know them 

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Exam board Key terms and Command words - get to know them 

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What does the investigation need to include?

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What does the investigation need to include?

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RGS Student Guide to the Independent Investigation

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RGS Student Guide to the Independent Investigation

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Padlet page for the Hazards Unit for AQA A level 

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Padlet page for the Hazards Unit for AQA A level 

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Additional resources, reading, videos, papers e.t.c.

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Use this to check you have included everything you need in your independent investigation.

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Key concepts; key terms and extra reading ideas

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Useful site for background reading

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An online resource from the Geological Society, aimed at students aged 14 - 16. Learn how the theory of plate tectonics has developed, what happens at different plate margins, and the tectonic history of the UK.

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AQA Scheme of Work for Teaching Hazards at A level 

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AQA Scheme of Work for Teaching Hazards at A level 

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Some great ideas, with key concepts, learning outcomes, activities and resources

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A brief overview of the how to go about writing up your NEA (by a very respected examiner)

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Another, more detailed guide to write up, this time by another teacher, teaching the course.

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These could be useful places to source information for the theory section of your independent investigation.

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Padlet page for the Water and Carbon cycles Unit for AQA A level

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Padlet page for the Water and Carbon cycles Unit for AQA A level

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Basic exam technique for each question

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RGS website to help with specific sections.

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RGS website to help with specific sections.

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Not sure which one to use? Not sure how to conduct it? Have a look at the website below.

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Mrs Starkey uses this for psychology- and it is useful starting point for the ethics of fieldwork

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This is a fab intro to a range of ideas for the NEA.

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Use this to check which sections you have covered/ need to catch up on.

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Use the mark scheme to guide you in understanding how to answer the question OR test your revision skills by answering questions in test conditions.

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find out how to remove them More information Accept Accept

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GEOCASES: Case Study: Human impact on the hydrological cycle

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Human impacts on the hydrological cycle are not new! However, as population growth continues and standards of living rise, there is increasingly more impact on all aspects of the hydrological cycle. Many of these impacts are negative but some are positive.

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We've just flicked the switch on moving all our digital resources to instant digital download - via our new subject stores.

For every subject you can now access each digital resource as soon as it is ordered. This will always be the latest edition of each resource too (and we'll update you automatically if there is an upgraded version to use).

Simply add the required resources to your cart, checkout using the usual options and your resources will be available to access immediately via your mytutor2u account.

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A Level Notes: Water and Carbon Cycles | tutor2u Geography

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We've just flicked the switch on moving all our digital resources to instant digital download - via our new subject stores. For every subject you can now access each digital resource as soon as it is ordered. This will always be the latest edition of each resource too (and we'll update you automatically if there is an upgraded version to use).

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New York City is no stranger to the effects of tropical storms and hurricanes. In fact, being located on something of a meteorological crossroads, lying in the zone where cold, Canadian Arctic air masses meet the warm Gulf Stream current, the Big Apple is in the firing line for both extreme winter storms and tropical cyclones.

One particularly notable storm that hit New York is the blizzard of 11 March 1888, which is considered one the USA's worst ever blizzards. As for hurricanes and tropical cyclones, a number of tropical cyclones have clipped New York as they worked their way northwards, three making a direct hit (or landfall) over New York City: the 1821 Norfolk and Long Island Hurricane, the 1893 New York Hurricane and Tropical Storm Irene in 2011. The 1938 New England Hurricane came very close, making landfall on nearby Long Island.

Meanwhile, several hurricanes and tropical storms have just clipped New York City, including Hurricane Agnes, which passed just west of New York in June 1972 and killed 24. Hurricane Hazel brought record-breaking gusts of 113 mph to Battery Park, Manhattan Island, in October 1954. More recently Tropical Storm Floyd brought 60 mph winds and flash flooding to New York City in September 1999, whilst Hurricane Irene made landfall on Coney Island in August 2011, sparking the first-ever mandatory evacuation of coastal residents as a precaution.

2012's Hurricane Sandy broke no wind or rainfall records in the Big Apple, but this massive hurricane proved one of the costliest ever to affect the USA. It brought winds up to 100 mph and widespread flooding from the associated storm surge. The surge flooded large parts of lower Manhattan, including subways and tunnels, caused mass power outages and destroyed thousands of homes and businesses, not just in New York but also in neighbouring New Jersey.
Some background on hurricanes and tropical cyclones
Before we look at how Sandy developed into one of New York City's most notorious visitors it's worth taking a closer look at some general aspects of tropical cyclones and hurricanes.

A tropical cyclone is the generic name given to a weather system over tropical or sub-tropical waters containing an organised area of thunderstorms, with cyclonic winds (anticlockwise in the northern hemisphere) around a low pressure centre. The tropical cyclone spectrum ranges from relatively small, weak storms called tropical depressions, with surface wind speeds less than 38 mph, to powerful hurricanes with surface wind speeds in excess of 160 mph. They are among the most dangerous natural hazards on earth and every year they cause considerable loss of life and damage to property.

Tropical cyclones typically start life over tropical oceans, forming when tropical thunderstorms are able to cluster and merge together in areas where the sea surface temperature is 27 ºC or more, where wind speed does not vary greatly with height and where winds near the ocean surface blow from different directions.

The sea provides a constant source of heat and moisture to 'fuel' the tropical cyclone. Winds near the ocean surface blowing from different directions help the warm, moist air rise and form cloud, and as wind speeds do not vary greatly with height, the cloud is able to grow into the giant thunderstorms.

When reaching land (known as 'making landfall'), tropical cyclones will quickly tend to weaken because their 'fuel source' has been cut off. They will also weaken if they move over areas of cooler sea. Or they can weaken if wind speeds near the upper parts of the tropical cyclone cloud increase - 'blowing' the tops of the cloud downstream, destroying some of the cyclone's organised structure and weakening it. Sometimes, however, a tropical cyclone will move away from the tropics and sub-tropics into the mid-latitudes and merge with existing mid-latitude weather systems. When this happens large and very powerful storms can form from the merger of the two systems.

There are various categories of tropical cyclone based on their wind speed. Weak tropical cyclones are called tropical depressions. When winds reach 39 mph they become known as tropical storms and they are then also given a name, which helps weather forecasters talk about them. Tropical cyclones can last more than a week and there can be more than one over any ocean at once, so giving them different names helps prevent confusion in weather forecasts. When winds reach 74 mph tropical storms over the Atlantic and north-east Pacific become known as hurricanes, and it is usually not until a storm becomes a hurricane that an 'eye' (an area of calm in the centre of a storm) becomes visible. In North America the Saffir-Simpson scale is used to categorise hurricane intensity - there are five categories and a hurricane is known as a 'major hurricane' if it reaches category 3 or higher.

Table One: Categories of tropical cyclone.

Figure One: Tropical cyclone distribution ( http://www.metoffice.gov.uk/weather/tropicalcyclone/facts).

Figure One shows where Atlantic hurricanes tend to occur. They usually take place between early June and late November, though a few have been known in both May and December. The peak in the Atlantic hurricane season is mid-August to around mid-October. Climatologically a powerful hurricane tracking close the USA's eastern seaboard becomes more likely later in the summer and during the autumn; later in the year such storms will tend to be steered away north-eastwards into the Atlantic Ocean.

Typically tropical cyclones move forward at speeds of around 10 to 15 mph, though they can move both more slowly or much quicker, perhaps as fast as 40 mph under some circumstances. Movement can also be erratic, making forecasting their track even more challenging. A typical hurricane is around 300 to 400 miles in diameter, though as we shall see later they can be much bigger. The highest wind speeds will be wrapped around the core of the hurricane, extending out 25 to 50 miles from the core in smaller hurricanes, and 150 to 200 miles in larger ones.

The size of tropical cyclones is such that they will tend to steer around larger scale weather systems. In the case of Hurricane Sandy we shall see that this played an important role in determining her track.
The evolution of Sandy
Sandy started life as a cluster of thunderstorms which left western Africa on 11 October 2012 and moved westward to reach the Caribbean Sea on 18 October. This cluster of thunderstorms then gradually intensified to become a tropical storm on the 22nd. It moved towards Jamaica and on 24 October officially became a hurricane, called Sandy, just south of Jamaica. Sandy then moved across Jamaica, bringing with it winds up to 85 mph, before crossing eastern Cuba on the 25th. Sandy was at its most intense as it crossed eastern Cuba and moved towards the Bahamas, sustaining winds of around 115 mph. Sandy hit the Bahamas on the 26th and then weakened a little, briefly dropping back to a tropical storm before re-intensifying to a hurricane on the 27th. During the 26th and 27th Sandy was also able to grow much bigger in size whilst tracking almost parallel to the east coast of the USA.

An area of high pressure developing over Ontario on the 28th spread eastwards on the 29th and 30th, and acted as a block to Sandy's path. Instead of curving north-eastwards into the Atlantic Ocean as many hurricanes do, Sandy was instead forced to turn north-westwards towards north-eastern USA. At the same time it interacted with a mid-latitude weather system which helped it to re-intensify and become much larger.

Sandy made landfall near Atlantic City, New Jersey, during the early evening of 29 October as one the most intense and damaging storms ever to affect the east coast of the USA. Sustained surface winds at landfall were close to 80 mph with gusts between 85 and 95 mph. After making landfall Sandy moved north-westwards, bringing heavy snow and blizzards to parts of the central Appalachian Mountains, and by the morning of 31 October no discernible storm centre could be found as the remnants of Sandy pressed on towards the Great Lakes and eastern Canada.

As Sandy was so big, wind damage covered a much larger area than would usually be expected from a hurricane. A larger area of strong winds led to a larger than usual storm surge. Sandy's arrival into the US coast on the 29th also coincided with both high tide and spring tide, meaning that the tide would be at around its highest level. In New York City this added an extra 20 to 50 cm to the high water mark.

The extensive damage Sandy caused was the result of a number of unfortunate coincidences. It was able to grow particularly big, it was steered by the weather pattern developing over Canada, its landfall coincided with one of the highest tides of the month, worsening the impact of the storm surge, and it was pushed into the New York area rather than the less densely populated area further north.
Sandy's impacts

Impacts extended to Canada, Wisconsin and Lake Michigan down the eastern side of the USA into the Bahamas, Cuba, Haiti, the Dominican Republic and Jamaica.

At least 286 people were killed either directly or indirectly by Sandy. There were 147 direct deaths: 72 in the USA and the rest mainly in Caribbean, including 54 in Haiti and 11 in Cuba.

In the USA of the 87 indirect deaths from Sandy, at least 50 were attributable to either falls by the elderly, carbon monoxide poisoning from inadequately ventilated generators and cooking equipment, or hypothermia as a cold snap followed Sandy and extended power outages left people without heating.

Sandy was Cuba's deadliest hurricane since 2005, whilst over the USA this was the greatest number of hurricane deaths from one storm outside of the southern states since Hurricane Agnes in 1972. Sandy was also the first hurricane to make landfall in Jamaica since 1988.

Sandy will go down as one of the USA's costliest hurricanes. Damage estimates, based on 2012 values, will top $60 billion. In New York City economic losses are estimated at exceeding $18 billion.

Elsewhere damage estimates, again based on 2012 values, exceeded $30 million in the Dominican Republic, $100 million in Jamaica and $750 million in Haiti, as Haiti's costliest hurricane on record. In Cuba damage estimates were around $2 billion, making it one of Cuba's costliest ever hurricanes.

346,000 houses were damaged or destroyed in New Jersey and 305,000 damaged or destroyed in New York and there were power outages from Indiana to Maine, with more than 8.5 million homes and businesses losing power. More than 18,000 flights were cancelled.

Sandy goes down as the largest hurricane on record in the Atlantic since at least 1988 in terms of diameter of gales. Among other meteorological 'highlights', Sandy brought 80 to 90 mph gusts over New York and New Jersey and its rain turned to heavy snow and blizzards over the Central Appalachians.

Sandy also brought heavy rain into north-east USA, the highest totals occurring south and west of New York City where typical amounts were around 25 mm whereas, for example, Washington DC had more than 125 mm and Niagara Falls close to 75 mm.

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Case Study - Hurricane Sandy - Metlink Teaching Weather and Climate

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New York and its history of storms New York City is no stranger to the effects of tropical storms and hurricanes. In fact, being located on something of a meteorological crossroads, lying in the zone where cold, Canadian Arctic air masses meet the warm Gulf Stream current, the Big Apple is in the firing line...

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Its not just about being a geography teacher!

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Geography is the study of the world we live in, its environments, landscapes and natural disasters, and the relationship between people and environments.

One of the most wide-ranging degree subjects, geography is a mix of social and physical sciences, combining study of the planet's physical properties with a focus on societies and how they interact.

Physical geography covers the Earth's climate, atmosphere, landscapes and natural processes including tectonic plates, glaciers, erosion and volcanology, while human geography covers the distribution and interactions of societies across the globe. While there are few well-defined boundaries, human geography covers population growth, globalisation, farming, forestry, fishing, urbanisation, transportation and tourism.

Many universities offer both human and physical geography programmes, while a number of institutions give students the option to pursue a combined course. However, there is almost always scope to specialise after the end of the first or second year of study.

What do you learn in a geography degree?

Modules may include topics on rivers, sustainability, environmental modelling, the physical environment, the politics of climate change, the making of the modern city, political geography and geopolitics, economic geography, coastal and estuarine environments, environmental hazards and energy resources.

Geography degrees often include field trips, with institutions offering fieldwork in a range of different countries to immerse students in local environments so they can apply knowledge learned in class. Trips may also enhance independent research and group skills. Many units are based on assessments carried out as part of a field trip, while lots of universities have links with overseas institutions in order to widen the range of potential fieldwork destinations.

The study of geography hones observational and analytical skills, the ability to take in vast quantities of information and also think critically, and the capacity to understand continuity and change in a range of contexts based on a broad knowledge base.
What can you do with a languages degree?
What can you do with an English literature degree?
What can you do with an English language degree?
What can you do with a psychology degree?
What can you do with a politics degree?
What can you do with a philosophy degree?
What can you do with a theology degree?
What should I study to do a geography degree?

While geography departments may well accept someone who hasn't studied geography before, prospective students are generally encouraged to study the subject at school and college. Certain BSc degrees will also ask for a maths or science qualification.

Other subjects that geography students have typically taken prior to beginning university include English literature, history, and various modern and classical languages.

However, there is no rule and entry requirements tend to depend on the type of geography course.

Physical geography programmes are more likely to demand a science-based qualification than human geography courses, which are generally more concerned with the social sciences such as politics and economics. Although some degrees such as population geography mix human geography with quantitative analysis methods and offer a bachelor of science degree.

Subjects that may overlap with a geography degree course, such as travel and tourism, are not necessarily the best option, and prospective students are generally encouraged not to focus too narrowly.

It is also healthy to take an interest in the environment, the outdoors, politics and the world around you.

What do people who study geography go on to do?

Geography students graduate with a combination of transferrable skills including problem-solving and critical thinking.

Nearly one-fifth of geography graduates find work in business, finance and human resources, and more than ten per cent go into marketing, public relations and sales.

Slightly more are employed in clerical work, while more and more are going into education, engineering and building.

Anna Rees graduated with a degree in geography from Cardiff University in 2021 and now works as a marketing executive at Loud Llama.

"I gained a lot of transferable skills from my degree, including writing press releases, communicating with the press, researching and, of course, writing," she says.

"Human geography is such a broad discipline, and I've been able to use my knowledge across these topics to help manage client accounts in varying industries. I think my degree was great at giving me an expansive knowledge to apply for a range of jobs, rather than limiting me to one specialism."

Other graduates go on to work as town planners, cartographers, surveyors, environmental consultants and campaigners, travel agents, emergency planners, landscape architects and meteorologists.

Graduates with degrees which include quantitative training are also particularly sought after among the social sciences or in policy research, development, poverty and climate change.

Famous people who studied geography

Theresa May, former UK prime minister, and the Duke of Cambridge are just two famous figures who have studied geography. Others include Immanuel Kant, the philosopher; Alexander von Humboldt, the naturalist and explorer; Hugh Dennis, the comedian; and television presenter Chris Tarrant.

Top athletes have also graduated in the subject, including Michael Jordan the basketball player; Olympic gold medal-winning rowers Sir Matthew Pinsent and James Cracknell; and former England rugby player Rob Andrew.

Anita Roddick, the founder of the Body Shop, and David Harvey, the geographer and anthropologist, also hold degrees in the subject.
Read more: Best universities for social science degrees

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What can you do with a geography degree?

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Geography is the study of the world we live in, its environments, landscapes and natural disasters, and the relationship between people and environments. One of the most wide-ranging degree subjects, geography is a mix of social and physical sciences, combining study of the planet's physical properties with a focus on societies and how they interact.

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Helpful overview of the Carbon and Water Cycle

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All life is based on the element carbon. Carbon is the major chemical constituent of most organic matter, fromfossil fuels to the complex molecules ( and ) that control genetic reproduction in organisms. Yet by weight, carbon is not one of the most abundant elements within the Earth's crust. In fact, the lithosphere is only 0.032% carbon by weight. In comparison, oxygen and silicon respectively make up 45.2% and 29.4% of the Earth's surface rocks.

Carbon is stored on our planet in the following major ( Figure 9r-1 and Table 9r-1): (1) as in living and dead organisms found in the ; (2) as the gas carbon dioxide in the atmosphere; (3) asorganic matter in ; (4) in thelithosphere as fossil fuels and sedimentary rock deposits such as , and ; and (5) in the oceans as dissolved atmosphericcarbon dioxide and as calcium carbonate shells in marine organisms.

Table 9r-1: Estimated major stores of carbon on the Earth.

Ecosystems gain most of theircarbon dioxide from the atmosphere. A number ofautotrophic organisms have specialized mechanisms that allow for absorption of this gas into their cells. With the addition of water and energy fromsolar radiation, these organisms use photosynthesis to chemically convert the carbon dioxide to carbon-based sugar molecules. These molecules can then be chemically modified by these organisms through the metabolic addition of other elements to produce more complex compounds like , , andamino acids. Some of the organic matter produced in plants is passed down toheterotrophic animals through consumption.

Carbon dioxide enters the waters of the ocean by simple . Once dissolved in seawater, the carbon dioxide can remain as is or can be converted into carbonate (CO ₃⁻²) or bicarbonate (HCO ₃⁻). Certain forms of sea life biologically fix bicarbonate with calcium (Ca⁺²) to produce calcium carbonate (CaCO ₃). This substance is used to produce shells and other body parts by organisms such as coral, clams, oysters, some protozoa, and some algae. When these organisms die, their shells and body parts sink to the ocean floor where they accumulate as carbonate-rich deposits. After long periods of time, these deposits are physically and chemically altered intosedimentary rocks. Ocean deposits are by far the biggest sink of carbon on the planet ( Table 9r-1).

Carbon is released from ecosystems as carbon dioxide gas by the process of respiration. Respiration takes place in both plants and animals and involves the breakdown of carbon-based organic molecules into carbon dioxide gas and some other compound by products. Thedetritus food chain contains a number of organisms whose primary ecological role is thedecomposition of organic matter into its abiotic components.

Over the several billion years of geologic history, the quantity of carbon dioxide found in the atmosphere has been steadily decreasing. Researchers theorized that this change is in response to an increase in the Sun's output over the same time period. Higher levels of carbon dioxide helped regulate the Earth's temperature to levels slightly higher than what is perceived today. These moderate temperatures allowed for the flourishing of plant life despite the lower output of solar radiation. An enhanced greenhouse effect, due to the greater concentration of carbon dioxide gas in the atmosphere, supplemented the production ofheat energy through higher levels of longwave counter-radiation. As the Sun grew more intense, several biological mechanisms gradually locked some of the atmospheric carbon dioxide intofossil fuels and sedimentary rock. In summary, this regulating process has kept the Earth's global average temperature essentially constant over time. Some scientists suggest that this phenomena is proof for theGaia hypothesis.

Carbon is stored in the lithosphere in both and forms. Inorganic deposits of carbon in the lithosphere include fossil fuels like , , and , oil , and based sedimentary deposits like . Organic forms of carbon in the lithosphere include ,organic matter, and substances found in soils. Some carbon dioxide is released from the interior of the lithosphere by . Carbon dioxide released by volcanoes enters the lower lithosphere when carbon-rich sediments and sedimentary rocks are and partially melted beneath boundary zones.

Since the Industrial Revolution, humans have greatly increased the quantity of carbon dioxide found in the Earth's atmosphere and oceans. Atmospheric levels have increased by over 30%, from about 275 parts per million (ppm) in the early 1700s to just over 365 PPM today. Scientists estimate that future atmospheric levels of carbon dioxide could reach an amount between 450 to 600 PPM by the year 2100. The major sources of this gas due to human activities include fossil fuel combustion and the modification of natural plant cover found in grassland, woodland, and forested ecosystems. Emissions from fossil fuel combustion account for about 65% of the additional carbon dioxide currently found in the Earth's atmosphere. The other 35% is derived from deforestation and the conversion of natural ecosystems into agricultural systems. Researchers have shown that natural ecosystems can store between 20 to 100 times more carbon dioxide than agricultural land-use types.

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All life is based on the element carbon . Carbon is the major chemical constituent of most organic matter, fromfossil fuels to the complex molecules ( and ) that control genetic reproduction in organisms. Yet by weight, carbon is not one of the most abundant elements within the Earth's crust.

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Questions to Consider:

State three factors which would cause a change to the Amazonian Forest Ecosystem.
Explain the impact of the change to the Amazonian Forest Ecosystem
When looking at the effect of climate change on ecosystems, why does the level of carbon dioxide in the atmosphere need to be considered as well as temperature change.

Summary:

Climate change can affect terrestrial and marine ecosystems which in turn has impacts on both the water and carbon cycles and then feeds back to the climate.

Direct human influence on vegetation can also lead to impacts on the climate, through the energy, water and carbon cycles.

Both changes in carbon dioxide and changes in climate have impacts on vegetation.

The interactive effects of elevated CO₂ and other global changes (such as climate change, nitrogen deposition and biodiversity loss) on ecosystem function are extremely complex.

Extreme weather events can have long lasting impacts on vegetation and the carbon and water cycles.

Case Studies
Vegetation changes in the Amazon basin
Further Information
How do land-use and land-cover changes cause changes in climate? What are the non-greenhouse gas effects of rising carbon dioxide on ecosystems? The Carbon Dioxide fertilisation effect
A Possible Amazon Basin Tipping Point

In general, climate exerts a dominant control over the distribution of terrestrial vegetation and surface properties that in turn affects the local climate by changing the local atmospheric water, Carbon and energy budgets. It has been hypothesized that these vegetation-climate feedbacks can explain shifts of vegetation through time: Firstly, increased transpiration may result in more precipitation, which in turn increases plant productivity, which amplifies transpiration further. Secondly, increased productivity leads to more canopy cover, which is darker (lower albedo) than snow and bare soil. This results in higher temperatures on the above ground parts of individual plants, thus also amplifying plant productivity.

The combined effects of a warming climate, higher levels of CO ₂, land-use change and increased Nitrogen availability may be responsible for primary productivity increases in many parts of the world. Enhanced productivity can lead to shifts in albedo and transpiration, which feed back to the water cycle through heat fluxes and precipitation.

Rising atmospheric CO ₂ concentrations affect ecosystems directly including through biological and chemical processes such as the carbon dioxide fertilisation effect. Plants can respond to elevated CO ₂ by opening their stomata less to take in the same amount of CO ₂ or by structurally adapting their stomatal density and size, both potentially reducing transpiration which increases the water efficiency of the plants but reduces the flow of water vapour, and the energy that goes with it, to the atmosphere. Paleo records over the Late Quaternary (past million years) show that changes in the atmospheric CO ₂ content between 180 and 280 ppmv had ecosystem-scale effects worldwide.

The direct effect of CO ₂ on plant physiology, independent of its role as a greenhouse gas, means that assessing climate change impacts on ecosystems and hydrology solely in terms of global mean temperature rise is an oversimplification. A 2°C rise in global mean temperature, for example, may have a different net impact on ecosystems depending on the change in CO ₂ concentration accompanying the rise: If a small change in CO ₂ causes a 2°C rise, or, if other greenhouse gases are mainly responsible for the rise, the vegetation response will be different to a 2°C rise triggered by a large increase in CO ₂.

Vegetation cover can be affected by climate change, with forest cover potentially decreasing (e.g. in the tropics) or increasing (e.g. in high latitudes). In particular, the Amazon forest has been the subject of several studies, generally agreeing that future climate change would increase the risk of tropical forest being replaced by seasonal forest or even savannah. The increase in atmospheric CO ₂ reduces the risk, through an increase in the water efficiency of plants.

Direct human changes to the land cover can also have impacts on the carbon and water cycles, as well as on the Earth's energy balance, through changes in surface albedo, transpiration and evaporation.

The coupling processes between terrestrial Carbon, Nitrogen and hydrological processes are extremely complex and far from well understood.

The effect of climate extremes on vegetation and the carbon and water cycles
Extreme events such as heatwaves, droughts and storms can cause vegetation death, fires and subsequent insect infestations which actually lead to a net output of carbon from ecosystems. For example, forests are characterized by the large biomass carbon stocks, which are vulnerable to wind damage, storms, ice storms, frost, drought, fire and pathogen or pest outbreaks. Trees take a long time to regrow, so the recovery times for forest biomass lost through extreme events are particularly long. Therefore, the effects of climate extremes on the carbon balance in forests are both immediate and lagged, and potentially long-lasting. Climate extremes may also trigger processes that decrease the turnover rate of some carbon pools and lead to additional long-term sequestration in these pools. A well-known example is charcoal created in fires, which generally persists longer in soils than leaf litter.

During the European 2003 heatwave, it was the lack of precipitation (and soil moisture) rather than the high temperatures which was the main factor limiting vegetation growth in the temperate and Mediterranean forest ecosystems.

Further Links:

There is a nice, short summary article at http://www.carbonbrief.org/blog/2011/03/new-scientific-papers-on-plants-and-carbon-dioxide/
http://www.nature.com/nature/journal/v500/n7462/fig_tab/nature12350_F2.html An overview of how carbon flows may be triggered, or greatly altered, by extreme events including extreme precipitation.
Figure 1 from http://www.mdpi.com/1424-8220/9/11/8624/htm shows a schematic view of the components of the climate system, their processes and interactions.

Ocean related feedback exists between climate variability, the water cycle and the carbon cycle. http://nasa-information.blogspot.co.uk/2010/11/ocean-earth-system.html
http://www.nasa.gov/images/content/703470main_InfoGraphic.jpg An infographic showing the limits to vegetation growth from soil nutrient availability.
A figure showing the ecosystem processes and feedbacks triggered by extreme climate events. http://www.nature.com/nature/journal/v500/n7462/fig_tab/nature12350_F1.html

How do land-use and land-cover changes cause changes in climate?
WG2 FAQ 4.1

Land use change affects the local as well as the global climate. Different forms of land cover and land use can cause warming or cooling and changes in rainfall, depending on where they occur in the world, what the preceding land cover was, and how the land is now managed. Vegetation cover, species composition and land management practices (such as harvesting, burning, fertilizing, grazing or cultivation) influence the emission or absorption of greenhouse gases. The brightness of the land cover affects the fraction of solar radiation that is reflected back into the sky, instead of being absorbed, thus warming the air immediately above the surface. Vegetation and land use patterns also influence water use and evapotranspiration, which alter local climate conditions. Effective land-use strategies can also help to mitigate climate change.

What are the non-greenhouse gas effects of rising carbon dioxide on ecosystems?
WG2 FAQ 4.2

Carbon dioxide (CO ₂) is an essential building block of the process of photosynthesis. Simply put, plants use sunlight and water to convert CO ₂ into energy. Higher CO ₂ concentrations enhance photosynthesis and growth (up to a point), and reduce the water used by the plant. This means that water remains longer in the soil or recharges rivers and aquifers. These effects are mostly beneficial; however, high CO ₂ also has negative effects, in addition to causing global warming. High CO ₂ levels cause the nitrogen content of forest vegetation to decline and can increase their chemical defences, reducing their quality as a source of food for plant-eating animals. Furthermore, rising CO ₂ causes ocean waters to become acidic, and can stimulate more intense algal blooms in lakes and reservoirs.

The Carbon Dioxide fertilisation effect
WG1 Box 6.3

Elevated atmospheric CO ₂ concentrations lead to higher leaf photosynthesis and reduced canopy transpiration, which in turn lead to increased plant water use efficiency and reduced fluxes of latent heat from the surface to the atmosphere. The increase in leaf photosynthesis with rising CO ₂, the so-called CO ₂ fertilisation effect, plays a dominant role in terrestrial biogeochemical models to explain the global land carbon sink, yet it is one of most unconstrained process in those models.
Field experiments provide a direct evidence of increased photosynthesis rates and water use efficiency (plant carbon gains per unit of water loss from transpiration) in plants growing under elevated CO ₂. These physiological changes translate into a broad range of higher plant carbon accumulation in more than two-thirds of the experiments and with increased net primary productivity (NPP) of about 20 to 25% at double CO ₂ from pre-industrial concentrations. Since the last IPCC report, new evidence is available from long-term Free-air CO ₂ Enrichment (FACE) experiments in temperate ecosystems showing the capacity of ecosystems exposed to elevated CO ₂ to sustain higher rates of carbon accumulation over multiple years. However, FACE experiments also show the diminishing or lack of CO ₂ fertilisation effect in some ecosystems and for some plant species. This lack of response occurs despite increased water use efficiency, also confirmed with tree ring evidence
Nutrient limitation is hypothesized as primary cause for reduced or lack of CO ₂ fertilisation effect observed on NPP in some experiments. Nitrogen and phosphorus are very likely to play the most important role in this limitation of the CO ₂ fertilisation effect on NPP, with nitrogen limitation prevalent in temperate and boreal ecosystems, and phosphorus limitation in the tropics. Micronutrients interact in diverse ways with other nutrients in constraining NPP such as molybdenum and phosphorus in the tropics. Thus, with high confidence, the CO ₂ fertilisation effect will lead to enhanced NPP, but significant uncertainties remain on the magnitude of this effect, given the lack of experiments outside of temperate climates.

A Possible Amazon Basin Tipping Point
WG2 Box 4.3

Since the last assessment report of the IPCC (AR4), our understanding of the potential of a large-scale, climate-driven, self-reinforcing transition of Amazon forests to a dry stable state (known as the Amazon "forest dieback") has improved. Modelling studies indicate that the likelihood of a climate-driven forest dieback by 2100 is lower than previously thought, although lower rainfall and more severe drought is expected in the eastern Amazon. There is now medium confidence that climate change alone (that is, through changes in the climate envelope, without invoking fire and land use) will not drive large-scale forest loss by 2100 although shifts to drier forest types are predicted in the eastern Amazon. Meteorological fire danger is projected to increase. Field studies and regional observations have provided new evidence of critical ecological thresholds and positive feedbacks between climate change and land-use activities that could drive a fire mediated, self-reinforcing dieback during the next few decades. There is now medium confidence that severe drought episodes, land use, and fire interact synergistically to drive the transition of mature Amazon forests to low-biomass, low-statured fire-adapted woody vegetation. Most primary forests of the Amazon Basin have damp fine fuel layers and low susceptibility to fire, even during annual dry seasons. Forest susceptibility to fire increases through canopy thinning and greater sunlight penetration caused by tree mortality associated with selective logging, previous forest fire, severe drought, or drought-induced tree mortality. The impact of fire on tree mortality is also weather-dependent. Under very dry, hot conditions, fire-related tree mortality can increase. Under some circumstances, tree damage is sufficient to allow light-demanding, flammable grasses to establish in the forest understorey, increasing forest susceptibility to further burning. There is high confidence that logging, severe drought, and previous fire increase Amazon forest susceptibility to burning. Landscape level processes further increase the likelihood of forest fire. Fire ignition sources are more common in agricultural and grazing lands than in forested landscapes, and forest conversion to grazing and crop lands can inhibit regional rainfall through changes in albedo and evapotranspiration or through smoke that can inhibit rainfall under some circumstances. Apart from these landscape processes, climate change could increase the incidence of severe drought episodes.
If recent patterns of deforestation (through 2005), logging, severe drought, and forest fire continue into the future, more than half of the region's forests will be cleared, logged, burned or exposed to drought by 2030, even without invoking positive feedbacks with regional climate, releasing 20±10 Pg of carbon to the atmosphere. The likelihood of a tipping point being reached may decline if extreme droughts (such as 1998, 2005, and 2010) become less frequent, if land management fires are suppressed, if forest fires are extinguished on a large scale, if deforestation declines, or if cleared lands are reforested. The 77% decline in deforestation in the Brazilian Amazon with 80% of the region's forest still standing demonstrates that policy-led avoidance of a fire-mediated tipping point is plausible.
WG2 Chapter 4, Figure 8.
The forests of the Amazon Basin are being altered through severe droughts, land use (deforestation, logging), and increased frequencies of forest fire. Some of these processes are self-reinforcing through positive feedbacks, and create the potential for a large-scale tipping point. For example, forest fire kills trees, increasing the likelihood of subsequent burning. This effect is magnified when tree death allows forests to be invaded by grasses, which are more flammable. Deforestation provides ignition sources to flammable forests, contributing to this dieback. Climate change contributes to this tipping point by increasing drought severity, reducing rainfall and raising air temperatures, particularly in the eastern Amazon Basin

Vegetation changes in the Amazon basin

WG2 Chapter 4, Figure 8. The forests of the Amazon Basin are already being altered through severe droughts, changes in land use (deforestation, logging), and increased frequencies of forest fire. Some of these processes are self-reinforcing through positive feedbacks, and create the potential for a large-scale tipping point. For example, forest fire kills trees, increasing the likelihood of subsequent burning. This effect is magnified when tree death allows forests to be invaded by flammable grasses. Deforestation provides ignition sources to flammable forests, contributing to this dieback. Climate change contributes to this tipping point by increasing drought severity, reducing rainfall and raising air temperatures, particularly in the eastern Amazon Basin.
There is a high risk that the large magnitudes and high rates of climate change this century will result in abrupt and irreversible regional-scale changes to terrestrial and freshwater ecosystems, especially in the Amazon and Arctic, leading to additional climate change.

There are plausiblemechanisms, supported by experimental evidence, observations, and climate model simulations, for the existence of ecosystem tipping points in the rainforests of the Amazon basin. Climate change (temperature and precipitation changes) alone isnot projected to lead to abrupt widespread loss of forest cover in the Amazon during this century. However, a projected increase in severe drought episodes, related to stronger El Niño events, together with land-use change and forest fires,would cause much of the Amazon forest to transform to less dense, drought- and fire-adapted ecosystems. This would risk reducing biodiversity in an important ecosystem, and would reduce the amount of carbon absorbed from the atmosphere through photosynthesis. It would also reduce the amount of evaporation, increasing the warming locally. Large reductions in deforestation, as well as wider application of effective wildfiremanagement would lower the risk of abrupt change in the Amazon.

Amazonian forests were estimated to have lost 1.6 PgC and 2.2 PgC following the severe droughts of 2005 and 2010, respectively.

A Possible Amazon Basin Tipping Point

Additional source:

Climate extremes and the carbon cycle, M. Reichstein, M. Bahn, P. Ciais, D. Frank, M. Mahecha, S. Seneviratne,.J. Zscheischler, C. Beer, N. Buchmann, D. Frank, D. Papale, A. Rammig, P. Smith, K. Thonicke, M. van der Velde, S. Vicca, A. Walz & M. Wattenbach, 2013, 500, Nature, 287-295.

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Ecosystem Feedbacks from Carbon and Water Cycle Changes - Metlink Teaching Weather and Climate

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Questions to Consider: State three factors which would cause a change to the Amazonian Forest Ecosystem. Explain the impact of the change to the Amazonian Forest EcosystemWhen looking at the effect of climate change on ecosystems, why does the level of carbon dioxide in the atmosphere need to be considered as well as temperature change....

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2017-0520 Fire in a building, Jecheon, Korea (Rep of) 2017-0521 Shipwreck; Philippines 2017-0523 Bus accident; Quintana Roo, Mexico 2017-0526 Train accident; Olympia (Washington state), United States 2017-0527 Rush during a funeral; Chittagong, Bangladesh 2017-0536 Fire in a shopping mall; Davao, Philippines 2017-0538 Collision between two boats; Tanganyika lake; Tanzania (Uni Rep) 2017-0539 Collision between two buses; Egypt 2017-0540 Collision between two buses; Egypt 2017-0541 A bus falls from a bridge; India

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Philippines response goes automated

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The Philippines government and an international aid agency are automating inventory systems to improve relief distribution in one of the world's most disaster-prone countries.

The World Food Programme (WFP) and Department of Social Welfare and Development (DSWD) are undertaking a US$46,000 customization of an open-source software commonly used in disaster relief, Sahana, to develop a national relief goods inventory and monitoring system, or RGIMS.

Sahana, developed in Sri Lanka after the 2004 earthquake and tsunami, was most recently used during the 2011 Sendai earthquake and tsunami in Japan, 2010 flooding in Pakistan and 2010 earthquake in Haiti, to name a few.

RGIMS covers inventory and warehousing, tracking and monitoring, and reporting and evaluation.

"We want [DSWD] managers to know what relief goods are in stock in real time," said Dragoslav Djuraskovic, WFP head of logistics in the Philippines.

In 2011, the National Resource Operations Centre (NROC) in the capital Manila - where all donations are handled - received, inventoried and re-packed an unknown quantity of goods.

"Everything that comes into our warehouse has to be encoded and sorted. Currently, we use Excel spreadsheets for all of this data. It's so tedious and the mere volume of the data makes the process prone to errors," said Ronald Reonal, 26, an administrative assistant at NROC.
Disaster-prone
On 6 February this year, an earthquake hit the southern province of Negros Occidental, leaving dozens dead, at least 70 missing and more than 32,000 displaced in 21 evacuation centres, according to the government's national disaster risk reduction and management council (NDRRMC) on 10 February.

Only two months earlier, Tropical Storm Washi swept through the southern island of Mindanao, affecting more than one million people.

DSWD officials told IRIN that in the midst of processing Washi donations, they have had to handle aid for earthquake survivors.

In 2011, the Philippines had 21 natural disasters affecting some seven million people and resulting almost 400 registered deaths, according to the World Health Organization Collaborating Centre for Research on the Epidemiology of Disasters ( CRED).

The same year, international donors pledged or sent US$31.4 million - which does not include $10.4 million for Tropical Storm Washi, which hit on 17 December.

Efficiency

"There will be no getting away from the manual counting and sorting of relief goods and donations," said Francia Fabian, NROC supervising administrative officer. "But RGIMS will at least make the process more efficient and our reporting more accurate."

Donors and authorized staff will be able to see, real-time, as supplies dwindle.

"There will be a threshold warning system that will alert the user on inventory that is running low, moderate and out of stock or about to expire," said George Pornaras, WFP's IT consultant for RGIMS.

At present, all DSWD officers call NROC for stock levels, which is faxed or emailed as an Excel file.

Pornaras said there were plans to set up internet-ready field offices with extra servers to ensure the system can function during an emergency.

According to Sahana's website, there are both on-line and stand-alone functions that do not require internet access.

RGIMS will be initially tested in five DSWD offices by March and is expected to be rolled out to 19 more offices nationwide by August 2012.

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The Philippines government and an international aid agency are automating inventory systems to improve relief distribution in one of the world's most disaster-prone countries.

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LO1. Water and Carbon cycles as Natural systems 

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LO: Understanding of the concept of 'systems frameworks' as a type of model fundamental to most areas of geographical understanding - watch and make notes

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Water and carbon cycles as natural systems

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Systems in Physical Geography Systems in physical geography Key terms: Closed system Open system Boundary Flow/transfer Input Store/component Output Closed system Has a transfer of energy both into and beyond the system boundary but not a transfer of matter Component/store Output Input Continual cycling of carbon may be viewed as

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LO1 - Online lesson about connections between systems

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LO1 - Online lesson about connections between systems

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Activity 2: Interactions within the atmosphere

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Life on Earth is well adapted to our planet's cycles. In our solar system, Earth is the only planet with air to breathe, liquid water to drink, and temperatures that are just right for life as we know it. Because our existence depends on our planet and its climate, we need to understand how what we do affects the Earth.

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The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure. It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below.

The lithosphere is the most rigid of Earth's layers. Although the rocks of the lithosphere are still considered elastic, they are not viscous. The asthenosphere is viscous, and the lithosphere-asthenosphere boundary (LAB) is the point where geologists and rheologists-scientists who study the flow of matter-mark the difference in ductility between the two layers of the upper mantle. Ductility measures a solid material's ability to deform or stretch under stress. The lithosphere is far less ductile than the asthenosphere. The elasticity and ductility of the lithosphere depends on temperature, stress, and the curvature of the Earth itself.

The lithosphere is also the coolest of Earth's layers. In fact, some definitions of the lithosphere stress its ability to conduct heat associated with the convection taking place in the plastic mantle below the lithosphere.

There are two types of lithosphere: oceanic lithosphere and continental lithosphere. Oceanic lithosphere is associated with oceanic crust, and is slightly denser than continental lithosphere. Continental lithosphere, associated with continental crust, can be much, much thicker than its oceanic cousin, stretching more than 200 kilometers (124 miles) below Earth's surface.

The most well-known feature associated with Earth's lithosphere is tectonic activity. Tectonic activity describes the interaction of the huge slabs of lithosphere called tectonic plate s.

The lithosphere is divided into 15 major tectonic plates: the North American, Caribbean, South American, Scotia, Antarctic, Eurasian, Arabian, African, Indian, Philippine, Australian, Pacific, Juan de Fuca, Cocos, and Nazca.

Most tectonic activity takes place at the boundaries of these plates, where they may collide, tear apart, or slide against each other. The movement of tectonic plates is made possible by thermal energy (heat) from the mantle part of the lithosphere. Thermal energy makes the rocks of the lithosphere more elastic.

Tectonic activity can shape the lithosphere itself: Both oceanic and continental lithospheres are thinnest at rift valleys and mid-ocean ridge s, where tectonic plates are shifting apart from one another. At these zones, the lithosphere is only as thick as the crust.

How the Lithosphere Interacts with Other Spheres

The cool, brittle lithosphere is just one of five great "spheres" that shape the environment of Earth. The other spheres are the biosphere (Earth's living things); the cryosphere (Earth's frozen regions, including both ice and frozen soil); the hydrosphere (Earth's liquid water); and the atmosphere (the air surrounding our planet). These spheres interact to influence such diverse elements as ocean salinity, biodiversity, and landscape.

For instance, the pedosphere is part of the lithosphere made of soil and dirt. The pedosphere is created by the interaction of the lithosphere, atmosphere, cryosphere, hydrosphere, and biosphere. Enormous, hard rocks of the lithosphere may be ground down to powder by the powerful movement of a glacier (cyrosphere). Weathering and erosion caused by wind (atmosphere) or rain (hydrosphere) may also wear down rocks in the lithosphere. The organic components of the biosphere, including plant and animal remains, mix with these eroded rocks to create fertile soil-the pedosphere.

The lithosphere also interacts with the atmosphere, hydrosphere, and cryosphere to influence temperature differences on Earth. Tall mountains, for example, often have dramatically lower temperatures than valleys or hills. The mountain range of the lithosphere is interacting with the lower air pressure of the atmosphere and the snowy precipitation of the hydrosphere to create a cool or even icy climate zone. A region's climate zone, in turn, influences adaptation s necessary for organisms of the region's biosphere.

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The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure. It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below.

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The cryosphere is the frozen water part of the Earth system

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About the Cryosphere | National Snow and Ice Data Center

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We live at the bottom of an invisible ocean called the atmosphere, a layer of gases surrounding our planet. Nitrogen and oxygen account for 99 percent of the gases in dry air, with argon, carbon dioxide, helium, neon, and other gases making up minute portions. Water vapor and dust are also part of Earth 's atmosphere. Other planets and moons have very different atmospheres, and some have no atmospheres at all.

The atmosphere is so spread out that we barely notice it, yet its weight is equal to a layer of water more than 10 meters (34 feet) deep covering the entire planet. The bottom 30 kilometers (19 miles) of the atmosphere contains about 98 percent of its mass. The atmosphere-air-is much thinner at high altitudes. There is no atmosphere in space.

Scientists say many of the gases in our atmosphere were ejected into the air by early volcanoes. At that time, there would have been little or no free oxygen surrounding the Earth. Free oxygen consists of oxygen molecules not attached to another element, like carbon (to form carbon dioxide) or hydrogen (to form water).

Free oxygen may have been added to the atmosphere by primitive organisms, probably bacteria, during photosynthesis. Photosynthesis is the process a plant or other autotroph uses to make food and oxygen from carbon dioxide and water. Later, more complex forms of plant life added more oxygen to the atmosphere. The oxygen in today's atmosphere probably took millions of years to accumulate.

The atmosphere acts as a gigantic filter, keeping out most ultraviolet radiation while letting in the sun's warming rays. Ultraviolet radiation is harmful to living things, and is what causes sunburns. Solar heat, on the other hand, is necessary for all life on Earth.

Earth's atmosphere has a layered structure. From the ground toward the sky, the layers are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Another layer, called the ionosphere, extends from the mesosphere to the exosphere. Beyond the exosphere is outer space. The boundaries between atmospheric layers are not clearly defined, and change depending on latitude and season.

Troposphere

The troposphere is the lowest atmospheric layer. On average, the troposphere extends from the ground to about 10 kilometers (6 miles) high, ranging from about 6 kilometers (4 miles) at the poles to more than 16 kilometers (10 miles) at the Equator. The top of the troposphere is higher in summer than in winter.

Almost all weather develops in the troposphere because it contains almost all of the atmosphere's water vapor. Clouds, from low-lying fog to thunderheads to high- altitude cirrus, form in the troposphere. Air masses, areas of high-pressure and low-pressure systems, are moved by winds in the troposphere. These weather systems lead to daily weather changes as well as seasonal weather patterns and climate systems, such as El Nino.

Air in the troposphere thins as altitude increases. There are fewer molecules of oxygen at the top of Mount Everest, Nepal, for example, than there are on a beach in Hawaii. This is why mountaineers often use canisters of oxygen when climbing tall peaks. Thin air is also why helicopters have difficulty maneuvering at high altitudes. In fact, a helicopter was not able to land on Mount Everest until 2005.

As air in the troposphere thins, temperature decreases. This is why mountaintops are usually much colder than the valleys beneath. Scientists used to think temperature continued to drop as altitude increased beyond the troposphere. But data collected with weather balloons and rockets have showed this is not the case. In the lower stratosphere, temperature stays almost constant. As altitude increases in the stratosphere, temperature actually increases.

Solar heat penetrates the troposphere easily. This layer also absorbs heat that is reflected back from the ground in a process called the greenhouse effect. The greenhouse effect is necessary for life on Earth. The atmosphere's most abundant greenhouse gases are carbon dioxide, water vapor, and methane.

Fast-moving, high-altitude winds called jet streams swirl around the planet near the upper boundary of the troposphere. Jet streams are extremely important to the airline industry. Aircraft save time and money by flying in jet streams instead of the lower troposphere, where air is thicker.

Stratosphere
The troposphere tends to change suddenly and violently, but the stratosphere is calm. The stratosphere extends from the tropopause, the upper boundary of the troposphere, to about 50 kilometers (32 miles) above the Earth's surface.

Strong horizontal winds blow in the stratosphere, but there is little turbulence. This is ideal for planes that can fly in this part of the atmosphere.

The stratosphere is very dry and clouds are rare. Those that do form are thin and wispy. They are called nacreous clouds. Sometimes they are called mother-of-pearl clouds because their colors look like those inside a mollusk shell.

The stratosphere is crucial to life on Earth because it contains small amounts of ozone, a form of oxygen that prevents harmful UV rays from reaching Earth. The region within the stratosphere where this thin shell of ozone is found is called the ozone layer. The stratosphere's ozone layer is uneven, and thinner near the poles. The amount of ozone in the Earth's atmosphere is declining steadily. Scientists have linked use of chemicals such as chlorofluorocarbons (CFCs) to ozone depletion.

Mesosphere

The mesosphere extends from the stratopause (the upper boundary of the stratosphere) to about 85 kilometers (53 miles) above the surface of the Earth. Here, temperatures again begin to fall.

The mesosphere has the coldest temperatures in the atmosphere, dipping as low as -120 degrees Celsius (-184 degrees Fahrenheit, or 153 kelvin). The mesosphere also has the atmosphere's highest clouds. In clear weather, you can sometimes see them as silvery wisps immediately after sunset. They are called noctilucent clouds, or night-shining clouds. The mesosphere is so cold that noctilucent clouds are actually frozen water vapor- ice clouds.

Shooting stars-the fiery burnout of meteors, dust, and rocks from outer space-are visible in the mesosphere. Most shooting stars are the size of a grain of sand and burn up before entering the stratosphere or troposphere. However, some meteors are the size of pebbles or even boulders. Their outer layers burn as they race through the mesosphere, but they are massive enough to fall through the lower atmosphere and crash to Earth as meteorites.

The mesosphere is the least-understood part of Earth's atmosphere. It is too high for aircraft or weather balloons to operate, but too low for spacecraft. Sounding rockets have provided meteorologists and astronomers their only significant data on this important part of the atmosphere. Sounding rockets are unmanned research instruments that collect data during sub-orbital flights.

Perhaps because the mesosphere is so little understood, it is home to two meteorological mysteries: sprites and elves. Sprites are reddish, vertical electrical discharges that appear high above thunderheads, in the upper stratosphere and mesosphere. Elves are dim, halo-shaped discharges that appear even higher in the mesosphere.

Ionosphere

The ionosphere extends from the top half of the mesosphere all the way to the exosphere. This atmospheric layer conducts electricity.

The ionosphere is named for ions created by energetic particles from sunlight and outer space. Ions are atoms in which the number of electrons does not equal the number of protons, giving the atom a positive (fewer electrons than protons) or negative (more electrons than protons) charge. Ions are created as powerful x-rays and UV rays knock electrons off atoms.

The ionosphere-a layer of free electrons and ions-reflects radio waves. Guglielmo Marconi, the "Father of Wireless," helped prove this in 1901 when he sent a radio signal from Cornwall, England, to St. John's, Newfoundland, Canada. Marconi's experiment demonstrated that radio signals did not travel in a straight line, but bounced off an atmospheric layer-the ionosphere.

The ionosphere is broken into distinct layers, called the D, E, F1, and F2 layers. Like all other parts of the atmosphere, these layers vary with season and latitude. Changes in the ionosphere actually happen on a daily basis. The low D layer, which absorbs high-frequency radio waves, and the E layer actually disappear at night, which means radio waves can reach higher into the ionosphere. That's why AM radio stations can extend their range by hundreds of kilometers every night.

The ionosphere also reflects particles from solar wind, the stream of highly charged particles ejected by the sun. These electrical displays create auroras (light displays) called the Northern and Southern Lights.

Thermosphere

The thermosphere is the thickest layer in the atmosphere. Only the lightest gases-mostly oxygen, helium, and hydrogen-are found here.

The thermosphere extends from the mesopause (the upper boundary of the mesosphere) to 690 kilometers (429 miles) above the surface of the Earth. Here, thinly scattered molecules of gas absorb x-rays and ultraviolet radiation. This absorption process propels the molecules in the thermosphere to great speeds and high temperatures. Temperatures in the thermosphere can rise to 1,500 degrees Celsius (2,732 degrees Fahrenheit, or 1,773 kelvin).

Though the temperature is very high, there is not much heat. How is that possible? Heat is created when molecules get excited and transfer energy from one molecule to another. Heat happens in an area of high pressure (think of water boiling in a pot). Since there is very little pressure in the thermosphere, there is little heat transfer.

The Hubble Space Telescope and the International Space Station (ISS) orbit the Earth in the thermosphere. Even though the thermosphere is the second-highest layer of Earth's atmosphere, satellites that operate here are in " low-Earth orbit."

Exosphere

The fluctuating area between the thermosphere and the exosphere is called the turbopause. The lowest level of the exosphere is called the exobase. At the upper boundary of the exosphere, the ionosphere merges with interplanetary space, or the space between planets.

The exosphere expands and contracts as it comes into contact with solar storms. In solar storms particles are flung through space from explosive events on the sun, such as solar flares and coronal mass ejections (CMEs).

Solar storms can squeeze the exosphere to just 1,000 kilometers (620 miles) above the Earth. When the sun is calm, the exosphere can extend 10,000 kilometers (6,214 miles).

Hydrogen, the lightest element in the universe, dominates the thin atmosphere of the exosphere. Only trace amounts of helium, carbon dioxide, oxygen, and other gases are present.

Many weather satellites orbit Earth in the exosphere. The lower part of the exosphere includes low-Earth orbit, while medium-Earth orbit is higher in the atmosphere.

The upper boundary of the exosphere is visible in satellite images of Earth. Called the geocorona, it is the fuzzy blue illumination that circles the Earth.

Extraterrestrial Atmospheres

All the planets in our solar system have atmospheres. Most of these atmospheres are radically different from Earth's, although they contain many of the same elements.

The solar system has two major types of planets: terrestrial planets (Mercury, Venus, Earth, and Mars) and gas giants (Jupiter, Saturn, Uranus, and Neptune).

The atmospheres of the terrestrial planets are somewhat similar to Earth's. Mercury's atmosphere contains only a thin exosphere dominated by hydrogen, helium, and oxygen. Venus' atmosphere is much thicker than Earth's, preventing a clear view of the planet. Its atmosphere is dominated by carbon dioxide, and features swirling clouds of sulfuric acid. The atmosphere on Mars is also dominated by carbon dioxide, although unlike Venus, it is quite thin.

Gas giants are composed of gases. Their atmospheres are almost entirely hydrogen and helium. The presence of methane in the atmospheres of Uranus and Neptune give the planets their bright blue color.

In the lower atmospheres of Jupiter and Saturn, clouds of water, ammonia, and hydrogen sulfide form clear bands. Fast winds separate light-colored bands, called zones, from dark-colored bands, called belts. Other weather phenomena, such as cyclones and lightning, create patterns in the zones and belts. Jupiter's Great Red Spot is a centuries-old cyclone that is the largest storm in the solar system.

The moons of some planets have their own atmospheres. Saturn's largest moon, Titan, has a thick atmosphere made mostly of nitrogen and methane. The way sunlight breaks up methane in Titan's ionosphere helps give the moon an orange color.

Most celestial bodies, including all the asteroids in the asteroid belt and our own moon, do not have atmospheres. The lack of an atmosphere on the Moon means it does not experience weather. With no wind or water to erode them, many craters on the Moon have been there for hundreds and even thousands of years.

The way a celestial body's atmosphere is structured and what it's made of allow astrobiologists to speculate what kind of life the planet or moon may be able to support. Atmospheres, then, are important markers in space exploration.

A planet or moon's atmosphere must contain specific chemicals to support life as we know it. These chemicals include hydrogen, oxygen, nitrogen, and carbon. Although Venus, Mars, and Titan have similar atmospheric gases, there is nowhere in the solar system besides Earth with an atmosphere able to support life. Venus' atmosphere is far too thick, Mars' far too thin, and Titan's far too cold.

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Writers

Melissa McDaniel
Erin Sprout
Diane Boudreau
Andrew Turgeon

Illustrators

Tim Gunther, Illustrator
Mary Crooks, National Geographic Society

Editors

Jeannie Evers, Emdash Editing
Kara West

Educator Reviewer

Nancy Wynne

Producer

Caryl-Sue, National Geographic Society

Sources

Dunn, Margery G. (Editor). (1989, 1993). "Exploring Your World: The Adventure of Geography." Washington, D.C.: National Geographic Society.

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Encyclopedic entry. We live at the bottom of an invisible ocean called the atmosphere, a layer of gases surrounding our planet. Nitrogen and oxygen account for 99 percent of the gases in dry air, with argon, carbon dioxide, helium, neon, and other gases making up minute portions.

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Physical systems interacting at the coastal system in iceland

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When you are surfing the south coast of Iceland there are so many places to explore and I know you can't see it all but if you have time I recommend taking the turn to Dyrhólaey.

is about 174 km from Reykjavík city or about 2 1/2 hour drive, not so far away from the beautiful little village (the southern most village in Iceland). Dyrhólaey is a small peninsula or promontory but is a former island. The whole area is really interesting and I recommend you spend some time there. I personally could stay there for hours. Simply love this place.

When driving on the main road #1 or ring road direction east you take a turn to the right to road 218. Drive that road to an end but please note you have two options i.e. either drive it all the way or make a right turn up the hill. That is because Dyrhólaey is divided into two parts i.e. the higher and lower part.

When turning right you are able to drive all the way to top which I highly recommend. When coming down again I also recommend you finish road 218 because on the lower part there is a great view and a beautiful beach to explore.

Please also note that during spring/summer time or nesting season Dyrhólaey has limited access. You should check before you leave because it could be different between season. It could be closed somewhere between 1st and 12 of May and then limited access until middle of June. During the nesting season the lower part is open to car traffic but the higher part is then only open to travellers on foot during daytime (09-18).

The birdlife during summer time is prosperous and there you should be able to see and discover beautiful puffins to name some species. Note to self though that the arctic tern nests there and can be very aggressive while protecting their nests.

Once you are on top in the higher area of Dyrhólaey you will have a breathtaking view to all directions. To the north you see Mýrdalsjökull glacier, to the east you will see the beautiful black lava seastacks Reynisdrangar and to the west you can view the endless black coastline and then in front of the peninsula there is a huge black arch of lava reaching out into the sea which the peninsula takes its name from. Dyrhólaey literally means "the hill island with the door hole". It's 120 m high and you are able to walk the arch or the bridge if you are not afraid of heights. Up there you can also find a spectacular and big "castle shaped" lighthouse.

In the lower area (which is one of my favourite spots) you can view an extremely cool rock called Arnardrangur "Eagle rock". The rock draws its name from eagles nesting in the rock but they haven't nested there since 1850.

It's very picturesque with Reynisdrangar and Reynisfjara in the background. When the tide is low you can walk along the black beach to the south and discover little caves and rock formations which is truly beautiful.

Hope you found my information about Dyrhólaey useful and I hope you will be able to go there if you haven't already. Please send me a line if you want to know more about Dyrhólaey.

See also:
Renting a car to drive there A night's stay in the lighthouse of Dyrhólaey Best Attractions by the Ring Road of Iceland South Coast Tours

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Dyrhólaey - The Arch with the Hole | Guide to Iceland

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When you are surfing the south coast of Iceland there are so many places to explore and I know you can't see it all but if you have time I recommend taking the turn to Dyrhólaey. is about 174 km from Reykjavík city or about 2 1/2 hour drive, not so far away from the beautiful little village (the southern most village in Iceland).

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Use this power point to make notes to inform the research on process of erosion, weathering, transportation and deposition

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10 Distinctive Landscapes 6 - Geomorphic Processes.pptx

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What can you do, are you unsure of?

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lewis'

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Chris's padlet page

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Padlet page for the Changing Places unit

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Padlet page for the Changing Places unit

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All resources for Changing Places

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Padlet page for Global Systems and Global Governance 

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Padlet page for Global Systems and Global Governance 

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All resources for GSGG

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Padlet Page for Contemporary Urban Environments

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Padlet Page for Contemporary Urban Environments

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All resources for CUE

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Just because you don't live near an active volcano doesn't mean you're immune to a catastrophic volcanic eruption.

Ever heard of a supervolcano? It's -- surprise! -- a really big volcano. (But it doesn't always look quite like what you'd think. Some of them, the calderas, look more like craters than cones.) Mount St. Helens or Iceland's Eyjafjallajökull are laughably small (very hot) potatoes compared to the realities of a lava under a gigantic caldera.

The question about supervolcanoes, it turns out, isn't whether one could destroy all life on Earth. It's when will it do it again.

That's right, folks. Around 200 million years ago, a supervolcano erupted with such insistent energy that 75 percent of the species on the planet were eradicated. It was so gigantic that it pulled apart North America and Africa and created the Atlantic Ocean in between. For 600,000 years, the supervolcano called CAMP (Central Atlantic Magmatic Province) erupted over and over [source: Newitz].

Now here's the thing that's bad news to all of those who are smugly enjoying their volcano-free neighborhoods. It wasn't that lava covered everything in sight or even that ash rained down hard enough to choke everything. Instead, it was the fallout of the pollution of the event; CO2 and carbon levels, for instance, exploded. The environment was ruined. Very little was able to bounce back. (Interesting to note that after the apocalypse, it was dinosaurs who were eventually able to evolve and take over before their own catastrophic end, proving that nobody wins for long [source: Blackburn, et al.].)

So are we vulnerable to another destructive eruption? In short, yes. Below Yellowstone Park lies a caldera that would knock not just your personal socks off, but the socks of those worldwide. Scientists recently discovered that the caldera is 55 by 20 miles (89 by 32 kilometers), and 3 to 9 miles (5 to 14 kilometers) below the surface [source: News.Au].

To put it in perspective, a Yellowstone eruption would be 25,000 times bigger than Mount St. Helens [source: Sealy]. And once again, it wouldn't necessarily be the lava flows and ash that kill you; it might be the terrible fallout from the lava flows and ash that destroy the Midwest, or the global cooling that would happen as a result.

Authors Note: Could a single volcanic eruption destroy all life on Earth?

I wanted to leave it to the end to point out that nobody really believes that the Yellowstone caldera is going to erupt anytime soon. In fact, it's probably not even likely that it will happen in the next thousand or ten thousand years. But still. Stay vigilant.

Related Articles

Sources

Blackburn, Terrence J., Paul E. Olsen, Samuel A. Bowring, Noah M. McLean, Dennis V. Kent, John Puffer, Greg McHone, E. Troy Rasbury, and Mohammed Et-Touhami, "Zircon U-Pb Geochronology Links the End-Triassic Extinction with the Central Atlantic Magmatic Province." Science. May 24, 2013. (June 23, 2014) http://www.sciencemag.org/content/340/6135/941.abstract

Hamilton, Andy. "What would happen if a super volcano erupted?" Wired. May 5, 2010. (June 23, 2014) http://www.wired.co.uk/news/archive/2010-05/05/what-would-happen-if-a-super-volcano-erupted

National Park Service. "Volcano questions and answers." U.S. Department of the Interior. (June 24, 2014) http://www.nps.gov/yell/naturescience/volcanoqa.htm

Newitz, Annalee. "Further evidence that volcanoes can destroy life on Earth." I09.com. March 21, 2013. (June 23, 2014) http://io9.com/further-evidence-that-volcanoes-can-destroy-life-on-ear-458267832

Newitz, Annalee. "What will really happen when the Yellowstone supervolcano erupts?" i09.com. May 17, 2013. (June 23, 2014) http://io9.com/what-will-really-happen-when-yellowstone-volcano-has-a-508274690

News.Au.Com. "Scientists have revealed the supervolcano lurking beneath Yellowstone National Park is twice as big as previously thought." Dec. 12, 2013. (June 23, 2014) http://www.news.com.au/travel/world-travel/scientists-have-revealed-the-supervolcano-lurking-beneath-yellowstone-national-park-is-twice-as-big-as-previously-thought/story-e6frfqc9-1226781381769

Sealy, Amanda. "How a supervolcano threaten Earth." Cnn.com. Aug. 30, 2012. (June 23, 2014) http://www.cnn.com/2012/08/30/us/wus-supervolcanoes-yellowstone/

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Could a single volcanic eruption destroy all life on Earth?

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Just because you don't live near an active volcano doesn't mean you're immune to a catastrophic volcanic eruption. Ever heard of a supervolcano? It's -- surprise! -- a really big volcano. (But it doesn't always look quite like what you'd think. Some of them, the calderas, look more like craters than cones.)

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Use this structure strip to help you improve the structure and style of your writing.

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Generic Structure Strips for 20 mark questions

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Try using this if you are still struggling with writing the 20 markers.

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A useful guide to using the mark scheme to maximise marks

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Designed to help and guide you with your independent investigation

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We're aware that Geography fieldwork might need to be a bit different for a while, so we've been working hard on a wide range of teaching resources to bring our classroom to you.

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Image

Photograph by Georg Gerster

Plate tectonics is a scientific theory that explains how major landforms are created as a result of Earth's subterranean movements. The theory, which solidified in the 1960s, transformed the earth sciences by explaining many phenomena, including mountain building events, volcanoes, and earthquakes.

In plate tectonics, Earth's outermost layer, or lithosphere-made up of the crust and upper mantle-is broken into large rocky plates. These plates lie on top of a partially molten layer of rock called the asthenosphere. Due to the convection of the asthenosphere and lithosphere, the plates move relative to each other at different rates, from two to 15 centimeters (one to six inches) per year. This interaction of tectonic plates is responsible for many different geological formations such as the Himalaya mountain range in Asia, the East African Rift, and the San Andreas Fault in California, United States.

The idea that continents moved over time had been proposed before the 20th century. However, a German scientist named Alfred Wegener changed the scientific debate. Wegener published two articles about a concept called continental drift in 1912. He suggested that 200 million years ago, a supercontinent he called Pangaea began to break into pieces, its parts moving away from one another. The continents we see today are fragments of that supercontinent. To support his theory, Wegener pointed to matching rock formations and similar fossils in Brazil and West Africa. In addition, South America and Africa looked like they could fit together like puzzle pieces.

Despite being dismissed at first, the theory gained steam in the 1950s and 1960s as new data began to support the idea of continental drift. Maps of the ocean floor showed a massive undersea mountain range that almost circled the entire Earth. An American geologist named Harry Hess proposed that these ridges were the result of molten rock rising from the asthenosphere. As it came to the surface, the rock cooled, making new crust and spreading the seafloor away from the ridge in a conveyer-belt motion. Millions of years later, the crust would disappear into ocean trenches at places called subduction zones and cycle back into Earth. Magnetic data from the ocean floor and the relatively young age of oceanic crust supported Hess's hypothesis of seafloor spreading.

There was one nagging question with the plate tectonics theory: Most volcanoes are found above subduction zones, but some form far away from these plate boundaries. How could this be explained? This question was finally answered in 1963 by a Canadian geologist, John Tuzo Wilson. He proposed that volcanic island chains, like the Hawaiian Islands, are created by fixed "hot spots" in the mantle. At those places, magma forces its way upward through the moving plate of the sea floor. As the plate moves over the hot spot, one volcanic island after another is formed. Wilson's explanation gave further support to plate tectonics. Today, the theory is almost universally accepted.

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Last Updated

August 17, 2022

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The theory of plate tectonics revolutionized the earth sciences by explaining how the movement of geologic plates causes mountain building, volcanoes, and earthquakes.

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A-level Geography students are required to write evaluative essays which, under timed conditions, for the examination boards AQA and Edexcel must be completed in around 25 to 30 minutes. For OCR, the time allocated is about 45 minutes.

In general, this represents around 2/3 pages of average-sized handwriting i.e. somewhere between 400 and 600 words, and 750 words for OCR. Evaluative essays should incorporate both an introduction and a formal conclusion, with several paragraphs of argument in between.

The command words now widely used are:

* Evaluate (appraising/judging usefulness e.g. suitability and validity)

* Assess (weigh up options, conclude re. effectiveness, success or otherwise)

In writing their essays, the key feature that students need to understand is the difference between descriptive or explanatory writing and evaluative writing.
Descriptive/explanatory writing
This usually consists of factual points which:

* outline the main features of a place, object, issue, idea, theory, strategy

* recall why these features have arisen because of particular factors, processes, actions or management objectives

* identify spatial/temporal variations

* make use of case study material to support the answer.

This consists of material which may additionally:

* critically reflect on the limitations of a particular explanation or on viewpoints/

perspectives/conflicts regarding an issue

* discuss the impacts of spatial/temporal variations in the operation of factors and processes

* examine relative success/failure

* use important geographic concepts, such as place, or establish connections and relationships between different ideas.

[Some examples of the differences between descriptive/explanatory and evaluative writing will appear in subsequent Substacks]
In a 400-600-word essay (20 marks), the introduction should probably not exceed 75 words, and is more likely to be around 50 words, in length. Three or four sentences can be sufficient to provide a concise definition of any key terms and to establish a focus and/or an argument, and maybe hint at a conclusion.

A series of roughly equal-sized paragraphs should then guide the reader through enough themes or examples for a credible conclusion or final judgement to be made. A sensible approach might be to write three to five 75/100-word paragraphs.

Note, there is a limit to how much AO1 credit can be gained from the inclusion of excessive amounts of information and data. The examination board AQA allocates an equal proportion of marks to knowledge (AO1) and the application of that knowledge (AO2), whereas both Edexcel and OCR have an imbalance where most of the credit is allocated to AO2.

It is therefore best to avoid:

* too much background

* irrelevant information

* too much detail. It is better to use some factual information or data (say 2/3 pieces per paragraph) together with some technical terminology.

NB. The use of any knowledge used must be both 'convincing' and relevant. Deconstructing a question
It is important to recognise the demands of a question.

'The economic impacts of earthquakes are always greater than the social impacts' To what extent do you agree?' Recognise the contention in this question - are they 'always greater'?

'Assess the importance of governance in the successful management of tectonic hazards'. Spot the hidden agenda. What other factors could be important?

'To what extent do you agree that seismic events will always generate more widespread and severe impacts than volcanic events?' Recognise the contention, and the scale and the range of impacts.

'Evaluate the importance of rebranding in the success of regeneration'. Note two hidden agendas here: importance and success. What criteria can be used for both?

'TNCs are the most significant factor in creating unequal flows of people and money within global systems. How far do you agree with this statement?' Here we have complicated demands: most significant factor?; people and money; inequality.
The conclusion
The first thing to say is that a clear conclusion must be evident, even if it consists of just one sentence. It should address the question directly and make a final judgement about the ideas/issues which the essay has focused on. However, it is advisable to produce a substantial conclusion - and not merely a perfunctory sentence.

This is because the mark scheme for the evaluative essays puts a high premium on the ability of candidates to:

(i) think and/or reflect critically

(ii) and/or make connections between different geographic ideas and issues to develop a topic overview.

(iii) or both.

When it comes to 'to what extent' or 'how far do you agree' questions:

* never 'sit on the fence'

* equally, it is best to avoid extreme agreement or disagreement

* An 'agree because, but......' or a 'disagree because, but......' judgement is often the best position to take.

A good conclusion acknowledges explicitly that any conclusion reached is likely to be partial because there are so many ways of thinking about the issue, and/or so many perspectives to consider. It should refer to the most significant facts which have featured in the main body of the essay (in support of an evidence-based final judgement). It may make reference to specialist geographical theories, terms or ideas in order to add 'weight' to the final judgement. Finally, it may establish connections between different ideas and themes that are featured in the essay.
Signposting language
Signposting language refers to ways in which an essay can be constructed in good English. Here are some examples:
Introducing ideas:
To evaluate the role of..... this essay aims to provide a discussion of....

This essay seeks to investigate/evaluate/assess the impact of .... in relation to....

One aspect which illustrates.... can be identified as...

The current debate about ..... has recently been challenged by .....
Expanding ideas:
Building on from the idea that ..... this section illustrates that ...

To further evaluate the role of ..... this section explores the idea that ....

Another line of argument on .... demonstrates that ....
Contrasting ideas:
However, another angle on this debate suggests that ....

In contrast to evidence which suggests .... an alternative view is that ....

Not all research shows that ..... Some evidence states that ....
Summation of a paragraph:
This evidence highlights that ....

There is therefore general agreement that....

The strength of such an approach is that....
Concluding:
Having considered all of the evidence, the extent to which there can be agreement with the statement is ...

The majority of the evidence presented in this essay shows that ....

To conclude, this essay has addressed a number of significant factors, which tend to point towards....
Linking words.
A good essay will make use of several linking words, which help to connect paragraphs, ideas and themes. The most common ones used are shown below

.

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This is the second of three Substacks on the topic of essay writing in A Level Geography.

As stated in an earlier Substack, in writing their essays, the key feature that students need to understand is the difference between descriptive or explanatory writing and evaluative writing.
Descriptive/explanatory writing
This usually consists of factual points which:

* outline the main features of a place, object, issue, idea, theory, strategy

* recall why these features have arisen because of particular factors, processes, actions or management objectives

* identify spatial/temporal variations

* make use of case study material to support the answer.

This consists of material which may additionally:

* critically reflect on the limitations of a particular explanation or on viewpoints/

perspectives/conflicts regarding an issue

* discuss the impacts of spatial/temporal variations in the operation of factors and processes

* examine relative success/failure

* use important geographic concepts, such as place, or establish connections and relationships between different ideas.

The following section seeks to illustrate the difference between descriptive/explanatory writing and evaluative writing, using a range of possible essay titles. Only a limited number of sentences are used in each case for this purpose, a short paragraph, but hopefully the differences will become transparent. Brief commentary is provided to help.
Title 1: Evaluate the role of mobile phone technology in creating a globalised world.
Descriptive/Explanatory writing
There are more than 7 billion mobile phones - more than one per person. This number has risen rapidly in recent years. Just ten years ago, there were less than one billion mobile phones. Mobile phones and other technologies are an important factor contributing to globalisation. By having a mobile phone, people can experience 'the shrinking world' and so become more globalised.
Commentary: this answer is largely factual. The only place where it becomes evaluative is in the final sentence, but it is basic.

Evaluative writing
There are more than 7 billion mobile phones - more than one per person. By having a mobile phone, people may experience 'the shrinking world' and become more globalised. However, many mobile users, such as those in North Korea, do not have full access to the internet and are 'excluded' from external influences. So, in some places, mobile phone growth may not necessarily be linked with globalisation.
Commentary: as in the previous answer, the first sentence is factual. The rest of the paragraph is evaluative.
Title 2: 'The causes of past climate change and current global warming are different.' How far do you agree with this statement?
Descriptive/Explanatory writing
There are differences between past climate change and current global warming. Past climate change was due to changes in the Earth's orbit from circular to elliptical. This changed the amount of sunlight received. Current global warming is said to be due to the emission of greenhouse gases, such as methane and carbon dioxide caused by deforestation and the burning of fossil fuels. This is called the enhanced greenhouse effect.
Commentary: this paragraph is entirely factual.

Evaluative writing
There are differences between past climate change and current global warming. This reflects the debate between natural causes and human causes. Natural causes included Milankovitch cycles (changes of the Earth's orbit) and volcanic eruptions. Human causes are associated with fossil fuel emissions and deforestation and are much more recent and rapid. Past climate change was cyclical whereas recent global warming is due to unsustainable human activity.
Commentary: the first and third sentences are factual. The remainder is evaluative.
Title 3: 'Every country will eventually lose its distinctive national identity as a result of globalisation.' How far do you agree with this statement?
Descriptive/Explanatory writing
TNCs such as McDonald's have spread around the world on account of globalisation. Their power is enormous, and they can be found in any city, although often they change the ingredients they use, such as the McArabia burger, which is available in Middle East countries. This is called glocalisation. Often, the menus are written in English, and it's estimated that because of this, 3,000 world languages will soon be lost out of about 6,000.
Commentary: this paragraph is entirely factual. Having said that, the final clause seems rather unlikely in terms of the numbers involved. It is typical of many students who seek to impress by using speculative facts.

Evaluative writing
TNCs like McDonald's can be found in almost every country in the world, with the effect that city centres begin to look the same wherever you are - called clone towns. This is yet another way in which national identity can be threatened, as places no longer look as individual. The spread of English as part of cultural imperialism is another way in which nations lose their sense of identity. Some languages become lost and so a key part of a county's culture is no longer as distinctive.
Commentary: this paragraph is entirely evaluative. The language may be a little exaggerated (threatened, cultural imperialism) but the underlying ideas are acceptable.

A subsequent Substack will examine conclusions.

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A good conclusion, read in isolation, should provide the reader with an overview of the preceding account. It should be possible to work out the topic matter that has been written about together with the general emphasis of the argument.
For the current A Level essays that are required, a conclusion should amount to between 75 and 100 words.

The first thing to say is that a clear conclusion must be evident, even if it consists of just one sentence. It should address the question directly and make a final judgement about the ideas/issues which the essay has focused on.

However, it is advisable to produce a more substantial conclusion - not merely a perfunctory sentence. This is because the mark schemes for the evaluative essays put a high premium on the ability of candidates to:

(i) think and/or reflect critically

(ii) and/or make connections between different geographic ideas and issues to develop a topic overview.

(iii) or both.

When it comes to 'to what extent' or 'how far do you agree' questions:

* never 'sit on the fence'

* equally, it is best to avoid extreme agreement or disagreement

* An 'agree because....., but......' or a 'disagree because ...., but......' judgement is often the best position to take.

A good conclusion acknowledges explicitly that any conclusion reached is likely to be partial because there are many ways of thinking about the issue, and/or many perspectives to consider. It should refer to the most significant facts which have featured in the main body of the essay (in support of an evidence-based final judgement). It may refer to specialist geographical theories, terms or ideas in order to add 'weight' to the final judgement. Finally, it may establish connections between different ideas and themes that are featured in the essay.

The following sections examines two conclusions to two different essay titles. A brief commentary is provided in each case.
Title 1: 'Globalisation is mainly driven by the actions of transnational corporations (TNCs).'Conclusion A:
Having looked at both sides of the question, on balance I believe that nowadays TNCs are the most powerful force driving globalisation. They have more money than many poor countries and can make their products profitable in almost any country by using glocalisation, as this essay has shown. However, technology is important too, especially the internet, so it is not just TNCs that are important in making globalisation happen.
Conclusion B: In conclusion, TNCs act alongside other forces. I certainly do not agree that TNCs drive political globalisation - this is more likely the work of bodies such as the UN, EU and IMF. Furthermore, powerful governments like the USA have driven geopolitical changes that make it easier for their own TNCs to promote economic globalisation. Finally, technology in conjunction with TNCs drives social globalisation (e.g. Facebook). So while the statement may largely be true for economic globalisation, I have shown that other forces are driving different aspects of globalisation. How far do you agree with this statement? Title 2: Assess the potential causes and impacts of changes to the water balance within a tropical rainforest that you have studied. Conclusion A: To conclude, generally the water balance of the Amazon is changing such that water is being lost from the system mainly due to human factors. Increased population has led to increased demand for resources putting a strain on our natural planet mostly felt by fragile environments such as the rainforest.
Commentary: an overview of the argument is provided in the first sentence. A single counterargument has been provided - the role of technology - adding some breadth to the argument.
Conclusion B: In summary, deforestation is causing the most impact on the Amazon rainforest in the short term, allowing more rainwater to reach the ground, and reducing evapotranspiration, whereas in the longer term it is likely that climate change will have the greatest impact. It is predicted that rainfall amounts will become less in total, and more variable. Climate change could in fact result in the decrease of the forest naturally through a drier climate, so the two main causes are interrelated.
Commentary: an overall assessment is provided in the final sentence. However, the preceding sentences flag up that the argument has recognised that there is not a single definition of globalisation - economic, social, political - and one can infer that these have been examined in turn.

Commentary: a vague conclusion that points to human factors driving change in the water balance. There seems to be no acknowledgement of any other factors. Similarly, the impacts of these changes are difficult to decipher.

Commentary: a stronger conclusion that points to two main causal factors - deforestation and climate change - with some clear reference to impacts on the water cycle. Furthermore, the final clause suggests a link between the two main themes.