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Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, including the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere and the interactions between them. The climate of a location is affected by its latitude/ longitude, terrain, altitude, land use and nearby water bodies and their currents.

Climates can be classified according to the average and typical variables, most commonly temperature and precipitation. The most widely used classification scheme was the Köppen climate classification. The Thornthwaite system, in use since 1948, incorporates evapotranspiration along with temperature and precipitation information and is used in studying biological diversity and how climate change affects it. Finally, the Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region.

Paleoclimatology is the study of ancient climates. Paleoclimatologists seek to explain climate variations for all parts of the Earth during any given geologic period, beginning with the time of the Earth's formation. Since very few direct observations of climate were available before the 19th century, paleoclimates are inferred from proxy variables. They include non-biotic evidence-such as sediments found in lake beds and ice cores-and biotic evidence-such as tree rings and coral. Climate models are mathematical models of past, present, and future climates. Climate change may occur over long and short timescales from various factors. Recent warming is discussed in global warming, which results in redistributions. For example, "a 3 °C [5 °F] change in mean annual temperature corresponds to a shift in isotherms of approximately 300-400 km [190-250 mi] in latitude (in the temperate zone) or 500 m [1,600 ft] in elevation. Therefore, species are expected to move upwards in elevation or towards the poles in latitude in response to shifting climate zones."

Climate (from Ancient Greek κλίμα 'inclination') is commonly defined as the weather averaged over a long period. The standard averaging period is 30 years, but other periods may be used depending on the purpose. Climate also includes statistics other than the average, such as the magnitudes of day-to-day or year-to-year variations. The Intergovernmental Panel on Climate Change (IPCC) 2001 glossary definition is as follows:

Climate in a narrow sense is usually defined as the "average weather," or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.

The World Meteorological Organization (WMO) describes " climate normals" as "reference points used by climatologists to compare current climatological trends to that of the past or what is considered typical. A climate normal is defined as the arithmetic average of a climate element (e.g. temperature) over a 30-year period. A 30-year period is used as it is long enough to filter out any interannual variation or anomalies such as El Niño-Southern Oscillation, but also short enough to be able to show longer climatic trends."

The WMO originated from the International Meteorological Organization which set up a technical commission for climatology in 1929. At its 1934 Wiesbaden meeting the technical commission designated the thirty-year period from 1901 to 1930 as the reference time frame for climatological standard normals. In 1982 the WMO agreed to update climate normals, and these were subsequently completed on the basis of climate data from 1 January 1961 to 31 December 1990. The 1961-1990 climate normals serve as the baseline reference period. The next set of climate normals to be published by WMO is from 1991 to 2010. Aside from collecting from the most common atmospheric variables (air temperature, pressure, precipitation and wind), other variables such as humidity, visibility, cloud amount, solar radiation, soil temperature, pan evaporation rate, days with thunder and days with hail are also collected to measure change in climate conditions.

The difference between climate and weather is usefully summarized by the popular phrase "Climate is what you expect, weather is what you get." Over historical time spans, there are a number of nearly constant variables that determine climate, including latitude, altitude, proportion of land to water, and proximity to oceans and mountains. All of these variables change only over periods of millions of years due to processes such as plate tectonics. Other climate determinants are more dynamic: the thermohaline circulation of the ocean leads to a 5 °C (41 °F) warming of the northern Atlantic Ocean compared to other ocean basins. Other ocean currents redistribute heat between land and water on a more regional scale. The density and type of vegetation coverage affects solar heat absorption, water retention, and rainfall on a regional level. Alterations in the quantity of atmospheric greenhouse gases determines the amount of solar energy retained by the planet, leading to global warming or global cooling. The variables which determine climate are numerous and the interactions complex, but there is general agreement that the broad outlines are understood, at least insofar as the determinants of historical climate change are concerned.

Climate classification

Climate classifications are systems that categorize the world's climates. A climate classification may correlate closely with a biome classification, as climate is a major influence on life in a region. One of the most used is the Köppen climate classification scheme first developed in 1899.

There are several ways to classify climates into similar regimes. Originally, climes were defined in Ancient Greece to describe the weather depending upon a location's latitude. Modern climate classification methods can be broadly divided into genetic methods, which focus on the causes of climate, and empiric methods, which focus on the effects of climate. Examples of genetic classification include methods based on the relative frequency of different air mass types or locations within synoptic weather disturbances. Examples of empiric classifications include climate zones defined by plant hardiness, evapotranspiration, or more generally the Köppen climate classification which was originally designed to identify the climates associated with certain biomes. A common shortcoming of these classification schemes is that they produce distinct boundaries between the zones they define, rather than the gradual transition of climate properties more common in nature.

Paleoclimatology

Paleoclimatology is the study of past climate over a great period of the Earth's history. It uses evidence with different time scales (from decades to millennia) from ice sheets, tree rings, sediments, pollen, coral, and rocks to determine the past state of the climate. It demonstrates periods of stability and periods of change and can indicate whether changes follow patterns such as regular cycles.

Details of the modern climate record are known through the taking of measurements from such weather instruments as thermometers, barometers, and anemometers during the past few centuries. The instruments used to study weather over the modern time scale, their observation frequency, their known error, their immediate environment, and their exposure have changed over the years, which must be considered when studying the climate of centuries past. Long-term modern climate records skew towards population centres and affluent countries. Since the 1960s, the launch of satellites allow records to be gathered on a global scale, including areas with little to no human presence, such as the Arctic region and oceans.

Climate variability is the term to describe variations in the mean state and other characteristics of climate (such as chances or possibility of extreme weather, etc.) "on all spatial and temporal scales beyond that of individual weather events." Some of the variability does not appear to be caused systematically and occurs at random times. Such variability is called random variability or . On the other hand, periodic variability occurs relatively regularly and in distinct modes of variability or climate patterns.

There are close correlations between Earth's climate oscillations and astronomical factors ( barycenter changes, solar variation, cosmic ray flux, cloud albedo feedback, Milankovic cycles), and modes of heat distribution between the ocean-atmosphere climate system. In some cases, current, historical and paleoclimatological natural oscillations may be masked by significant volcanic eruptions, impact events, irregularities in climate proxy data, positive feedback processes or anthropogenic emissions of substances such as greenhouse gases.

Over the years, the definitions of climate variability and the related term climate change have shifted. While the term climate change now implies change that is both long-term and of human causation, in the 1960s the word climate change was used for what we now describe as climate variability, that is, climatic inconsistencies and anomalies.

Climate change is the variation in global or regional climates over time. It reflects changes in the variability or average state of the atmosphere over time scales ranging from decades to millions of years. These changes can be caused by processes internal to the Earth, external forces (e.g. variations in sunlight intensity) or, more recently, human activities. In recent usage, especially in the context of environmental policy, the term "climate change" often refers only to changes in modern climate, including the rise in average surface temperature known as global warming. In some cases, the term is also used with a presumption of human causation, as in the United Nations Framework Convention on Climate Change (UNFCCC). The UNFCCC uses "climate variability" for non-human caused variations.

Earth has undergone periodic climate shifts in the past, including four major ice ages. These consisting of glacial periods where conditions are colder than normal, separated by interglacial periods. The accumulation of snow and ice during a glacial period increases the surface albedo, reflecting more of the Sun's energy into space and maintaining a lower atmospheric temperature. Increases in greenhouse gases, such as by volcanic activity, can increase the global temperature and produce an interglacial period. Suggested causes of ice age periods include the positions of the continents, variations in the Earth's orbit, changes in the solar output, and volcanism. However, these naturally-caused changes in climate occur on a much slower time scale than the present rate of change which is caused by the emission of greenhouse gases by human activities.

Climate models use quantitative methods to simulate the interactions and transfer of radiative energy between the atmosphere, oceans, land surface and ice through a series of physics equations. They are used for a variety of purposes; from the study of the dynamics of the weather and climate system, to projections of future climate. All climate models balance, or very nearly balance, incoming energy as short wave (including visible) electromagnetic radiation to the Earth with outgoing energy as long wave (infrared) electromagnetic radiation from the earth. Any imbalance results in a change in the average temperature of the earth.

Climate models are available on different resolutions ranging from >100 km to 1 km. High resolutions in global climate models are computational very demanding and only few global datasets exists. Global climate models can be dynamically or statistically downscaled to regional climate models to analyze impacts of climate change on a local scale. Examples are ICON or mechanistically downscaled data such as CHELSA (Climatologies at high resolution for the earth's land surface areas).

The most talked-about applications of these models in recent years have been their use to infer the consequences of increasing greenhouse gases in the atmosphere, primarily carbon dioxide (see greenhouse gas). These models predict an upward trend in the global mean surface temperature, with the most rapid increase in temperature being projected for the higher latitudes of the Northern Hemisphere.

Models can range from relatively simple to quite complex:

Simple radiant heat transfer model that treats the earth as a single point and averages outgoing energy

this can be expanded vertically (radiative-convective models), or horizontally

finally, (coupled) atmosphere-ocean-sea ice global climate models discretise and solve the full equations for mass and energy transfer and radiant exchange.

IPCC (2013). Stocker, T. F.; Qin, D.; Plattner, G.-K.; Tignor, M.; et al. (eds.). Climate Change 2013: The Physical Science Basis (PDF). Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK & New York: Cambridge University Press. ISBN 978-1-107-05799-9.. AR5 Climate Change 2013: The Physical Science Basis - IPCC

IPCC AR5 SYR (2014). The Core Writing Team; Pachauri, R. K.; Meyer, L. A. (eds.). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Geneva, Switzerland: IPCC.

Knutson, T.; Kossin, J.P.; Mears, C.; Perlwitz, J.; Wehner, M.F (2017). Wuebbles, D.J; Fahey, D.W; Hibbard, K.A; Dokken, D.J; Stewart, B.C; Maycock, T.K (eds.). Ch. 3: Detection and Attribution of Climate Change (PDF). doi:10.7930/J01834ND.

Rohli, Robert. V.; Vega, Anthony J. (2018). Climatology (fourth ed.). Jones & Bartlett Learning. ISBN 9781284126563.

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Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation.

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Reflection

The teamwork didn’t go as well as we thought. It is hard to communicate with each other when you live in different countries, have different schools and different lives. As already mentioned, communication was weak. This had an effect on time because it wasted most of our time waiting for a reply when actually it was best if we started with the project when waiting. If this happens again we can reflect on this and use the time wisely. With a little more effort and communication this project could have gone more easily. On the other hand, it was pretty fun to do, learning about different cities and getting to know others from different countries. Learning to communicate with others that have different experiences. So that is a positive side.

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Conclusion

Climate change affects our society by affecting a range of different social, cultural and natural resources. After completing our international project, we came to the conclusion that climate change is adversely affecting the environment, the economy and society. We observed in all cities (Nysa, Rotterdam and Buzet) a higher temperature in the city center than on the outskirts of the city. This is due to the urban heat island. The largest pollution was observed in the Netherlands and the smallest in Croatia. But this may be due to measurement errors, because we took measurements at other times.
And how do climate change affect the environment?
- the temperature is constantly rising - the last few years have not been as cold as winters. This is a global problem, not only in Rotterdam, Nysa or Buzet. It's about global warming and what is happening around the world that is causing this problem. Such as too many plastic products, tree felling and too much production of goods that must be transported or exported worldwide.
- Extreme weather phenomena and change in the structure of precipitation
Heavy rainfall and other extreme weather phenomena are becoming more common. This can lead to floods, deterioration of water quality or reduction of water resources in some regions.

We don't know how to end the problem of polluted environment, but we know that we PEOPLE must start doing something about it in order to continue living happily on Earth!

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Where were the measurements taken? (Netherlands)

The measurements were made in front of the school in Rotterdam. In the morning at 8:30 the measurements were made. So the temperature and the amount of CO2 was measured at the same time. The Dutch students did the measurements in the month of January.

Where were the measurements taken? (Poland)

The measurements were both made outside of the house of the students. Both in and outside of the city centre. These measurements were made at 7 am. The Polish students did the measurements in the month of December.

Where were the measurements taken?(Croatia)

The measurements for the temperature were taken in Buzet. The data for pollution was taken from an internet website because students don’t have any equipment for measuring it. It was measured in January and February at 11 am.

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                                                                    Croatia

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                                                                    Croatia

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                                                                Netherlands                                                          

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                                                                Netherlands                                                          

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                                                                       Poland

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                                                                       Poland

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Nysa is a small city in Poland.

Nysa has 44,419 inhabitants (population). It is the second biggest city from these three cities. The most important climatic factor in Nysa is the location. Nysa is located in the valley. Nysa has a few factories. Most residents move by car or public transport. Sometimes smog occurs in Nysa. There is a lake. This lake is 20 km². In Nysa there are a few parks and squares. Trees and plants clean the air. Nysa has a slight pollution problem because of these factors.

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Buzet is a small city in Croatia. Buzet has a population of 6000. The most important climate factors for Rotterdam and Nysa is the location. Whereas in Buzet the it's landscapes, mountains and lowland, this has a bigger impact. Buzet has a highland in which the weather changes. An example of this is foggy in the mornings and humit. Buzet also has some factories but not a majority of it, so no big factories. Almost every family owns at least one car (mainly because of the cities size) but it’s not a big problem for the environment because Buzet doesn’t have a lot of inhabitants. Since we also have a lot of nature like forests and rivers our air is not very polluted because the trees and plants take the CO2 from the air and from the ground. We can say that Buzet doesn’t have any pollution issues because of these factors.

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Rotterdam is one of the biggest cities of the Netherlands and the biggest city from the three cities that we are doing this project with. Rotterdam has 644.618 people living there. It is a very big economic city. It has a big harbour where boats come in from different countries with goods. Rotterdam also has lots of different factories in and around the city. Rotterdam is a very big city where lots of people work and go to school. Because of its size there are different kinds of work, schools and places to live. But most of the working people don’t live in Rotterdam but in small cities around and next to it. This is a problem because all these people need to get in and out of the city. Most of the people come by car, train, the subway and the bus. In Rotterdam a lot of people also come with the bike. It is healthy and doesn’t create pollution. But all the other ways aren't really good for the air pollution. This year, some of the public busses became electric.

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The amount of pollution that goes into the air can not be changed. But there can be measurements made so the amount so the amount is known and what the possibilities are to decrease that amount. With this project measurements will be made to see if the amount of carbon dioxide affects the temperature outside.

The last couple of years the amount of carbon dioxide has increased a lot and so has the temperature. In the past 20 years, the world's temperature has risen about two-thirds. Most carbon dioxide that goes into the air is caused by factories, plaines, cars, trains and more. But what most people don’t know is that the most amount of carbon dioxide is caused by natural factors. These natural factors are mostly oil, coal and gas that is released into the atmosphere. Gas releases greenhouse gases into the air. These greenhouse gases cause carbon dioxide and methane to go into the air. The extra amount of carbon dioxide and methane that goes into the air cause a higher temperature.

The students of this group live in three different cities. These three cities are: Rotterdam (The Netherlands), Buzet (Croatia) and Nysa (Poland). In these cities, the students go to school.

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This hypothesis was chosen because climate change is a very big and important thing right now. Everybody should think that there should be a change in how much pollution ends up in the atmosphere. Because of this, the climate is changing on earth. So animals die with their species, the north pole melts, with ice caps, this is a problem because polar bears can’t hide to chase their prey, meaning they starve and plants can’t stay alive. So for our generation it is very important to change the amount of pollution that goes into the atmosphere. We want to do this for the next generations so that they can live a nice and healthy life.

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Method of measurements (the Netherlands)

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Method of measurements (the Netherlands)

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1. To measure the temperature a thermometer was used.

2. To use the thermometer, it had to be plugged in our macbook.

3. While the thermometer was being used the data that it collected was sent to the macbook into google sheets.

4. To measure the CO2 in the air, a CO2 meter was used.

5. To use the CO2 meter it also had to be plugged in our macbook.

6. The data from the CO2 meter then also was put in google sheets.

7. With all the data that was collected, a chart was made

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Urban areas usually experience the urban heat island ( UHI) effect, that is, they are significantly warmer than surrounding rural areas. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak, under block conditions, noticeably during the summer and winter. The main cause of the UHI effect is from the modification of land surfaces while waste heat generated by energy usage is a secondary contributor. A study has shown that heat islands can be affected by proximity to different types of land cover, so that proximity to barren land causes urban land to become hotter and proximity to vegetation makes it cooler. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas.

Monthly rainfall is greater downwind of cities, partially due to the UHI. Increases in heat within urban centers increases the length of growing seasons and decreases the occurrence of weak tornadoes. The UHI decreases air quality by increasing the production of pollutants such as ozone, and decreases water quality as warmer waters flow into area streams and put stress on their ecosystems.

Not all cities have a distinct urban heat island, and the heat island characteristics depend strongly on the background climate of the area in which the city is located. Effects within a city can vary significantly depending on local environmental conditions. Heat can be reduced by tree cover and green space, which act as sources of shade and promote evaporative cooling. Other options include green roofs, passive daytime radiative cooling applications, and the use of lighter-colored surfaces and less absorptive building materials in urban areas, to reflect more sunlight and absorb less heat.

Climate change is not the cause of urban heat islands but it is causing more frequent and more intense heat waves which in turn amplify the urban heat island effect in cities. Compact, dense urban development may increase the urban heat island effect, leading to higher temperatures and increased exposure.

A definition of urban heat island is: "The relative warmth of a city compared with surrounding rural areas." This relative warmth is caused by "heat trapping due to land use, the configuration and design of the built environment, including street layout and building size, the heat-absorbing properties of urban building materials, reduced ventilation, reduced greenery and water features, and domestic and industrial heat emissions generated directly from human activities".

Cities often experience stronger urban heat island effects at night; effects can vary with location and topography of metropolitan areas

For most cities, the difference in temperature between the urban and surrounding rural area is largest at night. While temperature difference is significant all year round, the difference is generally bigger in winter. The typical temperature difference is several degrees between the city and surrounding areas. The difference in temperature between an inner city and its surrounding suburbs is frequently mentioned in weather reports, as in "68 °F (20 °C) downtown, 64 °F (18 °C) in the suburbs". In the United States, the difference during the day is between 0.6-3.9 °C (1-7 °F), while the difference during the night is 1.1-2.8 °C (2-5 °F). The difference is larger for bigger cities and areas with a high air humidity.

Though the warmer air temperature within the UHI is generally most apparent at night, urban heat islands exhibit significant and somewhat paradoxical diurnal behavior. The air temperature difference between the UHI and the surrounding environment is large at night and small during the day.

Throughout the daytime, particularly when the skies are cloudless, urban surfaces are warmed by the absorption of solar radiation. Surfaces in the urban areas tend to warm faster than those of the surrounding rural areas. By virtue of their high heat capacities, urban surfaces act as a giant reservoir of heat energy. For example, concrete can hold roughly 2,000 times as much heat as an equivalent volume of air. As a result, the large daytime surface temperature within the UHI is easily seen via thermal remote sensing. As is often the case with daytime heating, this warming also has the effect of generating convective winds within the urban boundary layer. It is theorized that, due to the atmospheric mixing that results, the air temperature perturbation within the UHI is generally minimal or nonexistent during the day, though the surface temperatures can reach extremely high levels.

At night, the situation reverses. The absence of solar heating leads to the decrease of atmospheric convection and the stabilization of urban boundary layer. If enough stabilization occurs, an inversion layer is formed. This traps urban air near the surface, and keeping surface air warm from the still-warm urban surfaces, resulting in warmer nighttime air temperatures within the UHI. Other than the heat retention properties of urban areas, the nighttime maximum in urban canyons could also be due to the blocking of "sky view" during cooling: surfaces lose heat at night principally by radiation to the comparatively cool sky, and this is blocked by the buildings in an urban area. Radiative cooling is more dominant when wind speed is low and the sky is cloudless, and indeed the UHI is found to be largest at night in these conditions.

The urban heat island temperature difference is not only usually larger at night than during the day, but also larger in winter than in summer.[citation needed ] This is especially true in areas where snow is common, as cities tend to hold snow for shorter periods of time than surrounding rural areas (this is due to the higher insulation capacity of cities, as well as human activities such as plowing). This decreases the albedo of the city and thereby magnifies the heating effect. Higher wind speeds in rural areas, particularly in winter, can also function to make them cooler than urban areas. Regions with distinct wet and dry seasons will exhibit a larger urban heat island effect during the dry season.[citation needed ]

If a city or town has a good system of taking weather observations the UHI can be measured directly. An alternative is to use a complex simulation of the location to calculate the UHI, or to use an approximate empirical method. Such models allow the UHI to be included in estimates of future temperatures rises within cities due to climate change.

Leonard O. Myrup published the first comprehensive numerical treatment to predict the effects of the urban heat island (UHI) in 1969. The heat island effect was found to be the net result of several competing physical processes. In general, reduced evaporation in the city center and the thermal properties of the city building and paving materials are the dominant parameters. Modern simulation environments include ENVI-met, which simulates all interactions between building and ground surfaces, plants and ambient air.

There are several causes of an urban heat island (UHI); for example, dark surfaces absorb significantly more solar radiation, which causes urban concentrations of roads and buildings to heat more than suburban and rural areas during the day; materials commonly used in urban areas for pavement and roofs, such as concrete and asphalt, have significantly different thermal bulk properties (including heat capacity and thermal conductivity) and surface radiative properties ( albedo and emissivity) than the surrounding rural areas. This causes a change in the energy budget of the urban area, often leading to higher temperatures than surrounding rural areas.

Pavements, parking lots, roads or, more generally speaking transport infrastructure, contribute significantly to the urban heat island effect. For example, pavement infrastructure is a main contributor to urban heat during summer afternoons in Phoenix, United States.

Another major reason is the lack of evapotranspiration (for example, through lack of vegetation) in urban areas. The U.S. Forest Service found in 2018 that cities in the United States are losing 36 million trees each year. With a decreased amount of vegetation, cities also lose the shade and evaporative cooling effect of trees.

Other causes of a UHI are due to geometric effects. The tall buildings within many urban areas provide multiple surfaces for the reflection and absorption of sunlight, increasing the efficiency with which urban areas are heated. This is called the " urban canyon effect". Another effect of buildings is the blocking of wind, which also inhibits cooling by convection and prevents pollutants from dissipating. Waste heat from automobiles, air conditioning, industry, and other sources also contributes to the UHI.

High levels of pollution in urban areas can also increase the UHI, as many forms of pollution change the radiative properties of the atmosphere. UHI not only raises urban temperatures but also increases ozone concentrations because ozone is a greenhouse gas whose formation will accelerate with the increase of temperature.

Climate change is not a cause but an amplifier of the urban heat island effect. The IPCC Sixth Assessment Report from 2022 summarized the available research accordingly: "Climate change increases heat stress risks in cities [...] and amplifies the urban heat island across Asian cities at 1.5°C and 2°C warming levels, both substantially larger than under present climates [...]."

The report goes on to say: "In a warming world, increasing air temperature makes the urban heat island effect in cities worse. One key risk is heatwaves in cities that are likely to affect half of the future global urban population, with negative impacts on human health and economic productivity."

There are unhelpful interactions between heat and built infrastructure: These interactions increase the risk of heat stress for people living in cities.

Aside from the effect on temperature, UHIs can produce secondary effects on local meteorology, including the altering of local wind patterns, the development of clouds and fog, the humidity, and the rates of precipitation. The extra heat provided by the UHI leads to greater upward motion, which can induce additional shower and thunderstorm activity. In addition, the UHI creates during the day a local low pressure area where relatively moist air from its rural surroundings converges, possibly leading to more favorable conditions for cloud formation. Rainfall rates downwind of cities are increased between 48% and 116%. Partly as a result of this warming, monthly rainfall is about 28% greater between 20 miles (32 km) to 40 miles (64 km) downwind of cities, compared with upwind. Some cities show a total precipitation increase of 51%.

One study concluded that cities change the climate in area 2-4 times larger than their own area. One 1999 comparison between urban and rural areas proposed that urban heat island effects have little influence on global mean temperature trends. Others suggested that urban heat islands affect global climate by impacting the jet stream.

UHIs have the potential to directly influence the health and welfare of urban residents. As UHIs are characterized by increased temperature, they can potentially increase the magnitude and duration of heat waves within cities. The number of individuals exposed to extreme temperatures is increased by the UHI-induced warming. The nighttime effect of UHIs can be particularly harmful during a heat wave, as it deprives urban residents of the cool relief found in rural areas during the night.

Increased temperatures have been reported to cause heat illnesses, such as heat stroke, heat exhaustion, heat syncope, and heat cramps.

High UHI intensity correlates with increased concentrations of air pollutants that gathered at night, which can affect the next day's air quality. These pollutants include volatile organic compounds, carbon monoxide, nitrogen oxides, and particulate matter. The production of these pollutants combined with the higher temperatures in UHIs can quicken the production of ozone. Ozone at surface level is considered to be a harmful pollutant. Studies suggest that increased temperatures in UHIs can increase polluted days but also note that other factors (e.g. air pressure, cloud cover, wind speed) can also have an effect on pollution.

Studies from Hong Kong have found that areas of the city with poorer outdoor urban air ventilation tended to have stronger urban heat island effects and had significantly higher all-cause mortality compared to areas with better ventilation. Another study employing advanced statistical methods in Babol city, Iran, revealed a significant increase in Surface Urban Heat Island Intensity (SUHII) from 1985 to 2017, influenced by both geographic direction and time. This research, enhancing the understanding of SUHII's spatial and temporal variations, emphasizes the need for precise urban planning to mitigate the health impacts of urban heat islands.

UHIs also impair water quality. Hot pavement and rooftop surfaces transfer their excess heat to stormwater, which then drains into storm sewers and raises water temperatures as it is released into streams, rivers, ponds, and lakes. Additionally, increased urban water body temperatures lead to a decrease in diversity in the water. For example, in August 2001, rains over Cedar Rapids, Iowa led to a 10.5C (18.9F) rise in the nearby stream within one hour, resulting in a fish kill which affected an estimated 188 fish. Since the temperature of the rain was comparatively cool, it could be attributed to the hot pavement of the city. Similar events have been documented across the American Midwest, as well as Oregon and California. Rapid temperature changes can be stressful to aquatic ecosystems.

Species that are good at colonizing can use conditions provided by urban heat islands to thrive in regions outside of their normal range. Examples of this include the grey-headed flying fox ( Pteropus poliocephalus) and the common house gecko ( Hemidactylus frenatus). Grey-headed flying foxes, found in Melbourne, Australia, colonized urban habitats following the increase in temperatures there. Increased temperatures, causing warmer winter conditions, made the city more similar in climate to the more northerly wildland habitat of the species.

With temperate climates, urban heat islands will extend the growing season, therefore altering breeding strategies of inhabiting species. This can be best observed in the effects that urban heat islands have on water temperature (see effects on water bodies).

Urban heat islands caused by cities have altered the natural selection process. Selective pressures like temporal variation in food, predation and water are relaxed causing a new set of selective forces to roll out. For example, within urban habitats, insects are more abundant than in rural areas. Insects are ectotherms. This means that they depend on the temperature of the environment to control their body temperature, making the warmer climates of the city perfect for their ability to thrive. A study done in Raleigh, North Carolina conducted on Parthenolecanium quercifex (oak scales), showed that this particular species preferred warmer climates and were therefore found in higher abundance in urban habitats than on oak trees in rural habitats. Over time spent living in urban habitats, they have adapted to thrive in warmer climates than in cooler ones.

Another consequence of urban heat islands is the increased energy required for air conditioning and refrigeration in cities that are in comparatively hot climates. The heat island effect costs Los Angeles about US$ 100 million per year in energy (in the year 2000). Through the implementation of heat island reduction strategies, significant annual net energy savings have been calculated for northern locations such as Chicago, Salt Lake City, and Toronto.

Strategies to improve urban resilience by reducing excessive heat in cities include: Planting trees in cities, white roofs and light-coloured concrete, green infrastructure (including green roofs), passive daytime radiative cooling.[citation needed ]

The temperature difference between urban areas and the surrounding suburban or rural areas can be as much as 5 °C (9.0 °F). Nearly 40 percent of that increase is due to the prevalence of dark roofs, with the remainder coming from dark-colored pavement and the declining presence of vegetation. The heat island effect can be counteracted slightly by using white or reflective materials to build houses, roofs, pavements, and roads, thus increasing the overall albedo of the city.

Concentric expansion of cities is unfavorable in terms of the urban heat island phenomenon. It is recommended to plan the development of cities in strips, consistent with the hydrographic network, taking into account green areas with various plant species. In this way, it was planned to build urban settlements stretching over large areas, e.g. Kielce, Szczecin and Gdynia in Poland, Copenhagen in Denmark and Hamburg, Berlin and Kiel in Germany.

Planting trees around the city can be another way of increasing albedo and decreasing the urban heat island effect. It is recommended to plant deciduous trees because they can provide many benefits such as more shade in the summer and not blocking warmth in winter. Trees are a necessary feature in combating most of the urban heat island effect because they reduce air temperatures by 10 °F (5.6 °C), and surface temperatures by up to 20-45 °F (11-25 °C).

Painting rooftops white has become a common strategy to reduce the heat island effect. In cities, there are many dark colored surfaces that absorb the heat of the sun in turn lowering the albedo of the city. White rooftops allow high solar reflectance and high solar emittance, increasing the albedo of the city or area the effect is occurring.

Using light-colored concrete has proven effective in reflecting up to 50% more light than asphalt and reducing ambient temperature. A low albedo value, characteristic of black asphalt, absorbs a large percentage of solar heat creating warmer near-surface temperatures. Paving with light-colored concrete, in addition to replacing asphalt with light-colored concrete, communities may be able to lower average temperatures. However, research into the interaction between reflective pavements and buildings has found that, unless the nearby buildings are fitted with reflective glass, solar radiation reflected off light-colored pavements can increase building temperatures, increasing air conditioning demands.

There are specific paint formulations for daytime radiative cooling that reflect up to 98.1% of sunlight.

Another option is to increase the amount of well-watered vegetation. These two options can be combined with the implementation of green roofs. Green roofs are excellent insulators during the warm weather months and the plants cool the surrounding environment. Air quality is improved as the plants absorb carbon dioxide with concomitant production of oxygen.

Green roofs may decrease the urban heat island effect. Green roofery is the practice of having vegetation on a roof; such as having trees or a garden. The plants that are on the roof increase the albedo and decreases the urban heat island effect. This method has been studied and criticized for the fact that green roofs are affected by climatic conditions, green roof variables are hard to measure, and are very complex systems.

The cost efficiency of green roofs is quite high because of several reasons.[citation needed ] For one, green roofs have over double the lifespan of a conventional roof, effectively decelerating the amount of roof replacements every year. In addition to roof-life, green roofs add stormwater management reducing fees for utilities. The cost for green roofs is more in the beginning, but over a period of time, their efficiency provides financial as well as health benefits. However, "A conventional roof is estimated to be $83.78/m ² while a green roof was estimated at $158.82/m ²."[clarification needed ]

Green parking lots use vegetation and surfaces other than asphalt to limit the urban heat island effect.

Street-side swale and adjacent pervious concrete sidewalk in Seattle, US. Stormwater is infiltrated through these features into soil, thereby reducing levels of urban runoff to city storm sewers.

Green infrastructure or blue-green infrastructure refers to a network that provides the "ingredients" for solving urban and climatic challenges by building with nature.[79] The main components of this approach include stormwater management, climate adaptation, the reduction of heat stress, increasing biodiversity, food production, better air quality, sustainable energy production, clean water, and healthy soils, as well as more anthropocentric functions, such as increased quality of life through recreation and the provision of shade and shelter in and around towns and cities.[80][81] Green infrastructure also serves to provide an ecological framework for social, economic, and environmental health of the surroundings.[82] More recently scholars and activists have also called for green infrastructure that promotes social inclusion and equality rather than reinforcing pre-existing structures of unequal access to nature-based services.[83]

A passive daytime radiative cooling roof application can double the energy savings of a white roof, attributed to high solar reflectance and thermal emittance in the infrared window, with the highest cooling potential in hot and dry cities such as Phoenix and Las Vegas. When installed on roofs in dense urban areas, passive daytime radiative cooling panels can significantly lower outdoor surface temperatures at the pedestrian level.

The phenomenon was first investigated and described by Luke Howard in the 1810s, although he was not the one to name the phenomenon. A description of the very first report of the UHI by Luke Howard said that the urban center of London was warmer at night than the surrounding countryside by 2.1 °C (3.7 °F).

Investigations of the urban atmosphere continued throughout the nineteenth century. Between the 1920s and the 1940s, researchers in the emerging field of local climatology or microscale meteorology in Europe, Mexico, India, Japan, and the United States pursued new methods to understand the phenomenon.

In 1929, Albert Peppler used the term in a German publication believed to be the first instance of an equivalent to urban heat island: städtische Wärmeinsel (which is urban heat island in German). Between 1990 and 2000, about 30 studies were published annually; by 2010, that number had increased to 100, and by 2015, it was more than 300.

Leonard O. Myrup published the first comprehensive numerical treatment to predict the effects of the urban heat island (UHI) in 1969. His paper surveys UHI and criticizes then-existing theories as being excessively qualitative.

Some studies suggest that the effects of UHIs on health may be disproportionate, since the impacts may be unevenly distributed based on a variety of factors such as age, ethnicity and socioeconomic status. This raises the possibility of health impacts from UHIs being an environmental justice issue.

There is a correlation between neighborhood income and tree canopy cover. Low-income neighborhoods tend to have significantly fewer trees than neighborhoods with higher incomes. Researchers hypothesized that less-well-off neighborhoods do not have the financial resources to plant and maintain trees. Affluent neighborhoods can afford more trees, on "both public and private property." Part of this is also that wealthier homeowners and communities can afford more land, which can be kept open as green space, whereas poorer ones are often rentals, where landowners try to maximize their profit by putting as much density as possible on their land.

Beginning in the 2020s, a number of cities worldwide began creating Chief Heat Officer positions to organize and manage work counteracting the urban heat island effect.

Bill S.4280, introduced to the U.S. Senate in 2020, would authorize the National Integrated Heat Health Information System Interagency Committee (NIHHIS) to tackle extreme heat in the United States. Successful passage of this legislation would fund NIHHIS for five years and would instate a $100 million grant program within NIHHIS to encourage and fund urban heat reduction projects, including those using cools roofs and pavements and those improving HVAC systems. As of July 22, 2020 the bill has not moved past introduction to Congress.

The city of New York determined that the cooling potential per area was highest for street trees, followed by living roofs, light covered surface, and open space planting. From the standpoint of cost effectiveness, light surfaces, light roofs, and curbside planting have lower costs per temperature reduction.

Los Angeles

Los Angeles TreePeople is an example of how tree planting can empower a community. Tree people provides the opportunity for people to come together, build capacity, community pride and the opportunity to collaborate and network with each other.

In 2021, Climate Adaptation Planning Analysis (CAPA) received funding from the National Oceanic and Atmospheric Administration to conduct Heat Mapping across the United States. Ten areas from Virginia - Abington, Arlington, Charlottesville, Farmville, Harrisonburg, Lynchburg, Petersburg, Richmond, Salem, Virginia Beach and Winchester - participated in the heat watch campaign. This campaign consisted of 213 Volunteers brought together by campaign organizers who made 490,423 Heat Measurements across 70 Routes total. After taking measurements throughout the day, equipment and data was sent back to CAPA where it was analyzed using machine learning algorithms. After analysis of the data, CAPA came back together with campaign organizers from each area to discuss potential plans for each town in the future.

Sydney, Australia has one of the worst urban heat islands ever. One example is from 4 January 2020 when Sydney's western suburbs were considered the "hottest place on Earth". Suburbs such as Bankstown and Parramatta recorded temperatures of 47.3 °C (117.1 °F) and 47.0 °C (116.6 °F) with Observatory Hill recording 43.7 °C (110.7 °F). The hottest suburb at the time was Penrith, which had a reading of 48.9 °C (120.0 °F). Despite all this, Sydney's central area was sitting at a comfortably hot 35 °C (95 °F) with coastal areas seldom reaching 30 °C (86 °F).

Multiple factors that cause this can be due to it being far from the coast, kilometres of identical houses with black roofs along with greenery being replaced by tarmac and black asphalt (absorbing more heat and radiating it) and little room for yards to grow trees (therefore less shade).

Though this is not the only time the urban heat island has played its role in Sydney's west, the mercury has climbed to 45.2 °C (113.4 °F) on 1 January 2006, 42.9 °C (109.2 °F) on 23 January 2010, 46.5 °C (115.7 °F) on 18 January 2013, 46.9 °C (116.4 °F) on 11 February 2017 and 47.3 °C (117.1 °F) on 7 January 2018.

These urban heat differences usually only range from 2 °C (36 °F) to 7 °C (45 °F), rarely exceeding 10 °C (50 °F). Sydney's biggest urban heat island difference was recorded on 1 February 2020, roughly a month after Penrith's maximum record. A reading of 34.8 °C (94.6 °F) was recorded at Sydney's Observatory Hill; meanwhile, the mercury skyrocketed to 46.9 °C (116.4 °F) in Penrith Lakes. What makes this remarkable is that it is a difference of 12.1 °C (53.8 °F) along with southwestern/mid-western Sydney suburbs seldom reaching 37 °C (99 °F).

# data[].attributes.attachment_link.description
Urban areas usually experience the urban heat island ( UHI) effect, that is, they are significantly warmer than surrounding rural areas. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak, under block conditions, noticeably during the summer and winter.

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This difference is caused by the multiple factors which form the urban heat island effect, these factors are:
•The larger amount of darker materials present such compared to rural areas.  The fact that cooling by radiation is lower in urban areas compared to rural areas.
• Less heat loss of buildings due to relatively low wind speeds in urban areas asphalt in urban areas compared to rural areas
• The extra heat which is released by human activities, such as motorized transport, air conditioning, heating, industries and factories in urban areas  compared to rural areas.

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1. Name of test site: Nysa, ul. Plac Staromiejski
2. Location of the test site: data source - GPS
3. Latitude: 50.5 N
Longitude: 17.3 E
Altitude: 190 m a.s.l.
4. There is a market north of the observation site - 550m
South of the observation point is a park - 200m
West of the observation site is a hospital - 300 m
To the east of the observation site there is a low-heat thermal power plant - 900 m
7. Ground at the observation site: asphalt, pavement
8. Area: cities
9. The degree of environmental transformation is high

# data[].attributes.body
1. Name of test site: Nysa, ul. Stęczyńskiego 1
2. Location of the test site (GPS data source):
latitude: 50-50'N
longitude: 17ᵒ30'S
altitude: 190 m a.s.l.
3. To the north of the observation point is: Park, approx. 200 m.
4. To the south of the observation point is: Housing estate, approx. 40 m.
5. To the west of the observation point are: Allotment gardens, approx. 30 m.
6. To the east of the observation point is: Row housing estate, approx. 50 m.
7. Ground at the observation site: soil, pavement, asphalt
8. This is the outskirts of the city
9. The degree of environmental transformation is medium

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                                                                                                                                                                    GLOBE research reports

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                                                                                                                                                                    GLOBE research reports

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Atmosphere research location description card

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                                                                                                                                                                GLOBE research reports

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                                                                                                                                                                GLOBE research reports

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Air temperature test

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Measuring instruments needed for testing in the project : 

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Measuring instruments needed for testing in the project : 

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1. thermometer

2. Airly app (for monitoring air pollution PM10)

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We should measure the temperature at 7.00 simultaneously in the city center and outside.  At the same time, we should measure air pollution in the city center and outside.

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Climate change has a different impact on the atmosphere in Nysa, Rotterdam and Buzet because these cities have different sizes, populations and locations in the temperate zone. Due to the urban heat island effect, temperatures in urban areas will be higher than  temperatures outside urban areas.  This means that the shorter the distance from a city or other large urban area from which temperature is measured, the higher the temperature will be.

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How will climate changes influence the environment (economy and society) of Nysa, Rotterdam and Buzet?

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Kristine
Stephanie

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Stiven
Alex

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Wiktoria
Julia

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From GLOBE to Erasmus (2018-2020) is an international project carried out by schools from Croatia (Buzet), the Netherlands (Rotterdam) and Poland (Nysa)