Microclimates

Find out about how to borrow weather instruments in order to be able to carry out a microclimate investigation with your school here, or more about urban heat islands here

What are microclimates?
What are the different types of microclimates?
What is an urban microclimate?
Urban precipitation
Smog
Urban winds
 

What are microclimates?

A microclimate is the distinctive climate of a small-scale area, such as a garden, park, valley or part of a city. The weather variables in a microclimate, such as temperature, rainfall, wind or humidity, may be subtly different from the conditions prevailing over the area as a whole and from those that might be reasonably expected under certain types of pressure or cloud cover. Indeed, it is the amalgam of many, slightly different local microclimates that actually makes up the microclimate for a town, city or wood.

It is these subtle differences and exceptions to the rule that make microclimates so fascinating to study, and these notes help to identify and explain the key differences which can be noticed by ground-level observations.

What are the different types of microclimates?

In truth, there is a distinctive microclimate for every type of environment on the Earth’s surface, and as far as the UK is concerned they include the following:

Upland regions

Upland areas have a specific type of climate that is notably different from the surrounding lower levels. Temperature usually falls with height at a rate of between 5 and 10 °C per 1000 m, depending on the humidity of the air. This means that even quite modest upland regions, such as The Cotswolds, can be significantly colder on average than somewhere like the nearby Severn Valley in Gloucestershire.

Occasionally, a temperature inversion can make it warmer above, but such conditions rarely last for long. With higher hills and mountains, the average temperatures can be so much lower that winters are longer and summers much shorter. Higher ground also tends to be windier, which makes for harsher winter weather. The effect of this is that plants and animals are often different from those at low levels.

Hills often cause cloud to form over them by forcing air to rise, either when winds have to go over them or they become heated by the sun. When winds blow against a hill-side and the air is moist, the base of the cloud that forms may be low enough to cover the summit. As the air descends on the other (lee) side, it dries and warms, sometimes enough to create a föhn effect. Consequently, the leeward side of hills and mountain ranges is much drier than the windward side. The clouds that form due to the sun’s heating sometimes grow large enough to produce showers, or even thunderstorms. This rising air can also create an anabatic wind on the sunny side of the hill. Sunshine-facing slopes (south-facing in the Northern Hemisphere, north-facing in the Southern Hemisphere) are warmer than the opposite slopes.

Apart from temperature inversions, another occasion when hills can be warmer than valleys is during clear nights with little wind, particularly in winter. As air cools, it begins to flow downhill and gathers on the valley floor or in pockets where there are dips in the ground. This can sometimes lead to fog and/or frost forming lower down. The flow of cold air can also create what is known as a katabatic wind.

Coastal regions

The coastal climate is influenced by both the land and sea between which the coast forms a boundary. The thermal properties of water are such that the sea maintains a relatively constant day to day temperature compared with the land. The sea also takes a long time to heat up during the summer months and, conversely, a long time to cool down during the winter. In the tropics, sea temperatures change little and the coastal climate depends on the effects caused by the daytime heating and night-time cooling of the land. This involves the development of a breeze from off the sea (sea breeze) from late morning and from off the land (land breeze) during the night. The tropical climate is dominated by convective showers and thunderstorms that continue to form over the sea but only develop over land during the day. As a consequence, showers are less likely to fall on coasts than either the sea or the land.

Around the Poles, sea temperatures remain low due to the presence of ice, and the position of the coast itself can change as ice thaws and the sea re-freezes. One characteristic feature is the development of powerful katabatic winds that can sweep down off the ice caps and out to sea.

In temperate latitudes, the coastal climate owes more to the influence of the sea than of the land and coasts are usually milder than inland during the winter and cooler in the summer. However, short-term variations in temperature and weather can be considerable. The temperature near a windward shore is similar to that over the sea whereas near a leeward shore, it varies much more. During autumn and winter, a windward shore is prone to showers while during spring and summer, showers tend to develop inland. On the other hand, a sea fog can be brought ashore and may persist for some time, while daytime heating causes fog to clear inland. A lee shore is almost always drier, since it is often not affected by showers or sea mist and even frontal rain can be significantly reduced. When there is little wind during the summer, land and sea breezes predominate, keeping showers away from the coast but maintaining any mist or fog from off the sea.

Forests

Tropical rainforests cover only about 6% of the earth’s land surface, but it is believed they have a significant effect on the transfer of water vapour to the atmosphere. This is due to a process known as evapotranspiration from the leaves of the forest trees. Woodland areas in more temperate latitudes can be cooler and less windy than surrounding grassland areas, with the trees acting as a windbreak and the incoming solar radiation being ‘filtered’ by the leaves and branches. However, these differences vary depending on the season, i.e. whether the trees are in leaf, and the type of vegetation, i.e. deciduous or evergreen. Certain types of tree are particularly suitable for use as windbreaks and are planted as barriers around fields or houses.

 

Urban regions

These are perhaps the most complex of all microclimates. With over 75% of the British population being classed as urban, it is no surprise that they are also the most heavily studied by students of geography and meteorology. Therefore, the rest of these notes focus on the various elements that constitute an urban microclimate.

What is an urban microclimate?

The table below summarises some of the differences in various weather elements in urban areas compared with rural locations.

Sunshine duration5 to 15% less
Annual mean temperature0.5-1.0 °C higher
Winter maximum temperatures1 to 2 °C higher
Occurrence of frosts2 to 3 weeks fewer
Relative humidity in winter2% lower
Relative humidity in summer8 to 10% lower
Total precipitation5 to 10% more
Number of rain days10% more
Number of days with snow14% fewer
Cloud cover5 to 10% more
Occurrence of fog in winter100% more
Amount of condensation nuclei10 times more

Urban heat islands

Marked differences in air temperature are some of the most important contrasts between urban and rural areas shown in the table above. For instance, Chandler (1965) found that, under clear skies and light winds, temperatures in central London during the spring reached a minimum of 11 °C, whereas in the suburbs they dropped to 5 °C.

Indeed, the term urban heat island is used to describe the dome of warm air that frequently builds up over towns and cities.

The formation of a heat island is the result of the interaction of the following factors:

  • the release (and reflection) of heat from industrial and domestic buildings;
  • the absorption by concrete, brick and tarmac of heat during the day, and its release into the lower atmosphere at night;
  • the reflection of solar radiation by glass buildings and windows. The central business districts of some urban areas can therefore have quite high albedo rates (proportion of light reflected);
  • the emission of hygroscopic pollutants from cars and heavy industry act as condensation nuclei, leading to the formation of cloud and smog, which can trap radiation. In some cases, a pollution dome can also build up;
  • recent research on London’s heat island has shown that the pollution domes can also filter incoming solar radiation, thereby reducing the build up of heat during the day. At night, the dome may trap some of the heat from the day, so these domes might be reducing the sharp differences between urban and rural areas;
  • the relative absence of water in urban areas means that less energy is used for evapotranspiration and more is available to heat the lower atmosphere;
  • the absence of strong winds to both disperse the heat and bring in cooler air from rural and suburban areas. Indeed, urban heat islands are often most clearly defined on calm summer evenings, often under blocking anticyclones.
Urban pollution dome and plume
Urban pollution dome and plume

The precise nature of the heat island varies from urban area to urban area, and it depends on the presence of large areas of open space, rivers, the distribution of industries and the density and height of buildings. In general, the temperatures are highest in the central areas and gradually decline towards the suburbs. In some cities, a temperature cliff occurs on the edge of town. This can be clearly seen on the heat profile below for Chester.

Urban heat island in Chester
Urban heat island in Chester

Urban precipitation

As noted previously, the greater presence of condensation nuclei over urban areas can lead to cities being wetter and having more rain days than surrounding rural areas. Indeed, it was often said that Rochdale, the famous mill town, had significantly smaller amounts of rain on Sundays when the town’s factories were closed.

However, other factors play a major role, especially the heat islands. These can enhance convectional uplift, and the strong thermals that are generated during the summer months may serve to generate or intensify thunderstorms over or downwind of urban areas. Storms cells passing over cities can be ‘refuelled’ by contact with the warm surfaces and the addition of hygroscopic particles. Both can lead to enhanced rainfall, but this usually occurs downwind of the urban area.

Smog

Smogs were common in many British cities in the late 19th and early 20th centuries, when domestic fires, industrial furnaces and steam trains were all emitting smoke and other hygroscopic pollutants by burning fossil fuels. The smogs were particularly bad during the winter months and when temperature inversions built up under high pressure, causing the pollutants to become trapped in the lower atmosphere and for water vapour to condense around these particles.

One of the worst of these ‘pea-soup fogs’ was the London smog of the winter of 1952/53. Approximately 4,000 people died during the smog itself, but it is estimated that 12,000 people may have died due to its effects. As a result, the Clean Air Act of 1956 was introduced to reduce these emissions into the lower atmosphere. Taller chimney stacks and the banning of heavy industry from urban areas were just two of the measures introduced and, consequently, fewer smogs were recorded in the UK during the 1960s and 1970s.

Research in the 1990s has shown, however, that another type of smog – photochemical – is now occurring in some urban areas as a result of fumes from car exhausts and the build up of other pollutants in the lower atmosphere which react with incoming solar radiation. The presence of a brown-coloured haze over urban areas is an indication of photochemical smog, and among its side effects are people experiencing breathing difficulties and asthma attacks.

Urban winds

Tall buildings can significantly disturb airflows over urban areas, and even a building 100 metres or so high can deflect and slow down the faster upper-atmosphere winds. The net result is that urban areas, in general, are less windy than surrounding rural areas.

However, the ‘office quarter’ of larger conurbations can be windier, with quite marked gusts. This is the result of the increased surface roughness that the urban skyline creates, leading to strong vortices and eddies. In some cases, these faster, turbulent winds are funnelled in between buildings, producing a venturi effect, swirling up litter and making walking along the pavements quite difficult.

Web page reproduced with the kind permission of the Met Office

Adaptation Strategies

Question to consider: Adaptation to climate change needs to be addressed in all urban policies. Discuss.

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wg2
Climate change adaptation as an iterative risk management process with multiple feedbacks. People and knowledge shape the process and its outcomes. Assessment of the widest possible range of potential impacts, including low probability risks with major consequences, is central to understanding risk management strategies. Monitoring and learning are important components of effective adaptation.WG2 Summary for Policy Makers Figure 3.

Summary:

  • Adaptation is the process of adjustment to actual or expected climate change and its effects. In human systems, adaptation seeks to moderate or avoid harm or exploit beneficial opportunities. In some natural systems, human intervention may facilitate adjustment to expected climate and its effects.
  • Throughout history, people and societies have adjusted to and coped with climate, climate variability and extremes with varying degrees of success.
  • For many indigenous and rural communities, lay knowledge is critical to adapting to environmental changes including climate change as livelihood activities such as herding, hunting, fishing and farming are connected to and dependent on weather and climate.
  • Adaptation is becoming embedded in some planning processes, with a focus on incremental adjustments and co-benefits.  In particular, Governments are starting to develop adaptation plans and policies and to integrate climate change considerations into broader development plans.
  • Responding to climate related risks involves decision making in a changing world, where the timing and severity of climate change impacts are uncertain and there are limits to the effectiveness of adaptation.
  • Adaptation choices now will affect the risk of climate change throughout the 21st century.

Case Studies

The impact of 3 urban policies in Paris on climate change adaptation and mitigation

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Further Information

Could economic approaches bias adaptation policy and decisions against the interests of the poor, vulnerable populations, or ecosystems?

WG2 Summary for Policy Makers, Figure 5. 
Maximum speeds at which species can move across landscapes. Human interventions, such as habitat fragmentation, can change the speeds of movement. The coloured horizontal lines show the speeds at which temperatures are expected to move across landscapes according to different projected warmings – RCP8.5 being a scenario where greenhouse emissions are high and the world warms most quickly. Species with maximum speeds below each line are expected to be unable to track warming in the absence of human intervention (such as assisted migration). They may still be able to adapt to new climates. The numbers of those which can neither move nor adapt will fall.WG2 Summary for Policy Makers, Figure 5.
WG2 Chapter 16, Figure 1.
A conceptual model of the determinants of acceptable, tolerable and intolerable risks – according to an individual or a society. Adaptation efforts try to keep impacts within the tolerable risk space, although these may be limited by opportunities and constraints. The shape of the shaded regions and dotted lines can change over time as attitudes and capacities change. WG2 Chapter 16, Figure 1.

 

Acceptable risks are those deemed so low that additional efforts at risk reduction, in this case climate adaptation efforts, are not justified. Tolerable risks relate to situations where adaptive, risk management efforts are required and effective for risks to be kept within reasonable levels. The scope of risks that fall within the tolerable area is influenced by adaptation opportunities and constraints. Therefore, the categorization of risks varies across spatial, jurisdictional, and temporal. Opportunities and constraints may be physical, technological, economic, institutional, legal, cultural, or environmental in nature.

Intolerable risks may be related to threats to core social objectives associated with health, welfare, security or sustainability. Risks become intolerable when practicable or affordable adaptation options to avoid escalating risks become unavailable. Therefore, a limit is a point when an intolerable risk must be accepted; the objective itself must be relinquished; or some adaptive transformation must take place to avoid intolerable risk. Such a discontinuity may take several forms such as individual’s decision to relocate, an insurance company’s decision to withdraw coverage, or a species’ extinction. The alternative to such discontinuities is an escalating and unmediated risk of losses. While individuals have their own perspectives about what are acceptable, tolerable or intolerable risks, collective judgements about risk are also codified through mechanisms such as engineering design standards, air and water quality standards, and legislation that establishes goals for regulatory action. There are also international agreements that establish norms and rights relevant to climate change risks, such as the Universal Declaration of Human Rights, the International Covenant on Civil and Political Rights, and the International Covenant on Economic, Social and Cultural Rights. Further, these high level responses often shape the constraints and opportunities to adaptation and responses to risk at lower levels through the distribution of resources, institutional design, and support of capacity development. If these risks and discontinuities have global-scale consequences, they can be linked to ‘key vulnerabilities’ to climate change. Consistent with our framing of adaptation limits, such key vulnerabilities would need to be assessed in terms of the limits they imply for specific social actors, species and ecosystems.

WG2 Chapter 17, Figure 1.
The narrowing of adaptation from the space of all possible adaptations (pale yellow) to what will be done (blue). The factors written in black show the constraints on the size of the circle, i.e. the factors preventing the blue circle being as large as the pale yellow one. WG2 Chapter 17, Figure 1.

 

A number of factors will limit strategy adoption and preclude elimination of all climate change effects. The first outside circle represents the “adaptation needs”, i.e. the set of adaptation actions that would be required to avoid any negative effect (and capture all positive effects) from climate change. It can be reduced by climate change mitigation, i.e. by limiting the magnitude of climate change.

The second circle represents the subset of adaptation actions that are possible considering technical and physical limits. Improving what can be done, for instance through research and development, can expand this circle. The area between the first and second circles is the area of “unavoidable impacts” that one cannot adapt to (for instance, it is impossible to restore outdoor comfort under high temperature). The third circle represents the subset of adaptation actions that are desirable considering limited resources and competing priorities: some adaptation actions will be technically possible, but undesirable because they are too expensive and there are better alternative ways of improving welfare (e.g., investing in health or education). This circle can be expanded through economic growth, which increases resources that can be dedicated to adaptation. Finally, the last circle represents what will be done, taking into account the fact that market failures or practical, political, or institutional constraints will make it impossible to implement some desirable actions. The area between the first and the last circles represents residual impacts (i.e. the impacts that will remain after adaptation, because adapting to them is impossible, too expensive, or impossible due to some barriers).

Key regional risks from climate change and the potential for reducing risks through adaptation and mitigation

WG2 Assessment box spm2 table 1: AfricaAsiaAustralasiaCentral/ South AmericaEuropeNorth AmericaOceanPolar RegionsSmall Islands, Key.

Could economic approaches bias adaptation policy and decisions against the interests of the poor, vulnerable populations, or ecosystems?

(WG2 FAQ 17.2)

A narrow economic approach can fail to account adequately for such items as ecosystem services and community value systems, which are sometimes not considered in economic analysis or undervalued by market prices, or for which data is insufficient. This can bias decisions against the poor, vulnerable populations, or the maintenance of important ecosystems. For example, the market value of timber does not reflect the ecological and hydrological functions of trees nor the forest products whose values arise from economic sectors outside the timber industry, like medicines. Furthermore some communities value certain assets (historic buildings, religious sites) differently than others. Broader economic approaches, however, can attach monetary values to non-market impacts, referred to as externalities, placing an economic value on ecosystem services like breathable air, carbon capture and storage (in forests and oceans) and usable water. The values for these factors may be less certain than those attached to market impacts, which can be quantified with market data, but they are still useful to provide economic assessments that are less biased against ecosystems.
But economic analysis, which focuses on the monetary costs and benefits of an option, is just one important component of decision making relating to adaptation alternatives, and final decisions about such measures are almost never based on this information alone. Societal decision making also accounts for equity – who gains and who loses – and for the impacts of the measures on other factors that are not represented in monetary terms. In other words, communities make decisions in a larger context, taking into account other socioeconomic and political factors. What is crucial is that the overall decision-framework is broad, with both economic and non-economic factors being taken into consideration. A frequently used decision-making framework that provides for the inclusion of economic and non-economic indicators to measure the impacts of a policy, including impacts on vulnerable groups and ecosystems, is multicriteria analysis (MCA). But as with all decision making approaches, the a challenge for MCA and methods like it is the subjective choices that have to be made about what weights to attach to all the relevant criteria that go into the analysis, including how the adaptation measure being studied impacts poor or vulnerable populations, or how fair it is in the distribution of who pays compared to who benefits.

The impact of 3 urban policies in Paris on climate change adaptation and mitigation

Urban policies have many goals, such as enhancing the quality of life and the city’s economic competitiveness by means of affordable housing and office space, amenities and efficient public services.

They also have social objectives aimed at poverty and social segregation issues, safety and security, and public health and environmental goals, such as reducing air and water pollution and preserving natural areas. Urban policies now also face new challenges from climate change, including adaptation and mitigation needs.

Five possible policy goals:

  • Climate change mitigation: reducing greenhouse gas emissions (from transport, heating and air conditioning).
  • Adaptation and natural risk reduction: reducing the number of people living in flood prone areas.
  • Natural area and biodiversity protection: minimising the total urbanised area.
  • Housing affordability: access to affordable housing has impacts on the quality of life and competitiveness of a city.
  • Policy neutrality: all geographical areas benefit equally from policies.

The graph below shows the effectiveness of 3 policies in Paris as measured against these policy goals. The three policies are:

1) a greenbelt policy,
2) a public transport subsidy and
3) a zoning policy to reduce the risk of flooding with building prohibited in flood prone areas.

WG2 Chapter 17, figure 3.
Consequences of three policies in the Paris agglomeration: a greenbelt policy, a public transport subsidy and a zoning policy to reduce the risk of flooding (building prohibited in flood prone areas). The axes are orientated such that moving towards the edge of the plot represents a positive outcome. WG2 Chapter 17, figure 3.

By implementing all three policies, the outcome, considering both positive and negative impacts on the five policy goals, is better than a ‘do nothing scenario’ measured against the five policy goals. Therefore, climate goals can be reached more efficiently and with higher social acceptability, if they are implemented through taking into account existing strategic urban planning, rather than by creating new, independent climate-specific plans.  

 

 

 

 

Additional Source:

Trade-offs and synergies in urban climate policies, V. Viguié & S. Hallegatte, Nature Climate Change 2, 334–337 (2012), doi:10.1038/nclimate1434

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Global Atmospheric Circulation

Climate Graph Practice

1. Pick an item of clothing and look at its label to see where it was made.

2. Visit https://en.climate-data.org/ to find your chosen country and find the weather by month averages for the average temperature (degrees C) and precipitation (mm).

3. Plot the precipitation as a bar graph using the left-hand axis.

4. Plot the temperature as crosses in the middle of the month. Then join the crosses together as a line. Use the Reading example below for reference.

5. How do the January temperatures in the location your item of clothing was made compare to the January temperatures in Reading?________________________________________________________________________________________________________________________________________________________________________________

6. How do the July temperatures compare?________________________________________________________________________________________________________________________________________________________________________________

7. How does the January precipitation compare?________________________________________________________________________________________________________________________________________________________________________________

8. How does the July precipitation compare?________________________________________________________________________________________________________________________________________________________________________________

9. What’s the biggest contrast between the two locations? Why do you think that is?________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

15. Climate Crisis

Weather and Climate: a Teachers’ Guide

Pathway: Climate

Changing Global ClimateUK ClimateChanging UK climate – Climate Crisis

Lesson overview: In this lesson we explore the language used to talk about climate change and look in detail at sea level rise, tipping points and UN climate negotiations.

The Climate Crisis movement grew during 2018 with the formation of Extinction Rebellion and Greta Thunberg’s Schools Climate Strike.   The language used by both politicians and the public to describe climate change was transformed over the space of a few months; Blue Planet 2 sensitised the UK public to the environmental impacts of our lives, Extinction Rebellion was formed to demand greater and faster action to reduce the impacts of climate change and Greta Thunberg’s Schools Climate Strike spread across the world.  The discourse changed and legally binding commitments were demanded from national governments to reduce emissions and limit warming to 1.5oC following an IPCC report.

Learning objectives:

  • To consider a range of facts and opinions on climate change.

  • To decide if we are in a climate crisis.

  • To understand what tipping points are and their impact on climate change.

Key Teaching Resources

The Climate Crisis PowerPoint
The Climate Crisis PowerPoint (easier)
The Climate Crisis Worksheet
The Climate Crisis Worksheet (easier)
Climate Crisis Global Effects Homework

Teacher CPD/ Extended Reading

Climate Crisis_More for Teachers

Alternative or Extension Resources

Climate Negotiations in the Classroom resource

Weather and Climate: a Teachers’ Guide

14. Changing UK Climate

Weather and Climate: a Teachers’ Guide

Pathway: Climate

Past Climate ChangeChanging Global ClimateUK Climate Changing UK climate

Lesson overview: In this lesson we use the Central England Temperature record to explore changing UK weather and look at the projected impacts of climate change on the UK.

The UK climate has always changed and in over recent decades has become warmer. Over the coming century it is projected to become warmer and wetter in winter and hotter and drier in summer. Although change is unlikely to be dramatic, its cumulative impact will be significant and will affect human populations, landscapes and the natural world.  Adaptation and mitigation can help to ameliorate some of the negative impacts of our changing climate, though some populations, landscapes and ecosystems could be severely affected if the most extreme forecasts are realised

Learning objectives:

  • To understand how climate (precipitation and temperature) has changed over time in the UK

  • To be able to classify the potential impacts of changing climate on the UK.

Key Teaching Resources

Changing UK Climate PowerPoint
Changing UK Climate PowerPoint (easier)
Changing UK Climate Worksheet
Changing UK Climate Worksheet (easier)
Changing UK Climate Homework
Changing UK Climate Futures Homework

Teacher CPD/ Extended Reading

Changing UK Climate_More for Teachers

Alternative or Extension Resources

 

Weather and Climate: a Teachers’ Guide

13. UK Climate

Weather and Climate: a Teachers’ Guide

Pathway: Climate

Climate Zones – Past Climate ChangeChanging Global ClimateUK Climate

Lesson overview: In this lesson we revisit climate zones before exploring regional climate differences across the UK and the reasons for them.

Although the climate of the UK is largely Oceanic, some upland areas are Subpolar Oceanic and some small regions of Scotland are Subarctic or Tundra.  Physical factors including prevailing winds, topography, altitude, latitude, distance to the sea, aspect and urbanisation are the primary factors influencing smaller scale regional variations within the UK’s climate.

Learning objectives:

  • To understand how the UK’s climate varies regionally.

  • To be able to explain why the UK’s climate varies regionally.

  • To be able to relate the UK’s climate to where you live.

Key Teaching Resources

UK Climate PowerPoint
UK Climate Worksheet
UK Climate Graph Homework
Reasons for UK Climate Differences

Teacher CPD/ Extended Reading

UK Climate – More for Teachers

Alternative or Extension Resources

UK climate data exercise

Weather and Climate: a Teachers’ Guide

12. Changing Global Climate

Weather and Climate: a Teachers’ Guide

Pathway: Climate

Past Climate ChangePolar Climate – Hot Deserts – Changing Global Climate

Lesson overview: In this lesson we look at this historical relationship between carbon dioxide and global temperature and the Greenhouse Effect before moving on to consider future greenhouse gas emission scenarios.  

Greenhouse gases warm the Earth through intercepting the flow of heat from the Earth into space. The Intergovernmental Panel on Climate Change has co-ordinated research that shows unequivocally that global climate has changed as a result of the impact of humans on the concentration of greenhouse gases in the atmosphere and other aspects of the climate system and will continue to do so.  Neither the magnitude nor impacts of climate change will be uniformly felt around the world. As our understanding of predicted impacts continues to improve so does our ability to prepare for them.  Uncertainty stems from several sources – the response of governments, human populations, complex interactions and feedback effects between different components of the climate system. 

Learning objectives:

  • To be able to describe the major changes to temperature and CO2 over short and longer periods of time.

  • To be able to explain global warming and reasons why climate changes.

  • To evaluate what might happen to CO2 levels and temperature in the future.

Key Teaching Resources

Changing Global Climate PowerPoint
Changing Global Climate PowerPoint (easier)
Changing Global Climate Worksheet
Changing Global Climate Worksheet (easier)
Changing global climates homework

Teacher CPD/ Extended Reading

Changing Global Climate – More for Teachers

Alternative or Extension Resources

Changing climate: Climate stripes

Weather and Climate: a Teachers’ Guide

11. Hot Deserts

Weather and Climate: a Teachers’ Guide

Pathway: Climate

 Climate ZonesPast Climate ChangePolar Climate – Hot Deserts

Lesson overviewIn this lesson we look at the characteristics and locations of hot deserts and the adaptations of animals and vegetation found there.

Hot deserts have less than 250mm precipitation per year and daytime temperatures that may approach 50oC.   Hot deserts cover 14.2% of the Earth’s surface, their distribution largely determined by the global atmospheric circulation.   Physical factors such as altitude or latitude determine deserts with the most extreme values of precipitation/temperature. Their characteristics and distribution will change over long periods of time due to the Milankovitch cycles and Continental Drift.  Climate change is projected to have complex effects and the size of arid regions is expected to grow. The plants and animals that live in the deserts around the world have adapted to cope with the extreme climate.

Learning objectives:

  • To be able to describe the characteristics and location of at least one hot desert.

  • To understand why hot deserts are hot and dry.

  • To be able to draw and interpret a climate graph of a hot desert.

  • To understand animal and plant adaptations to the hot desert climate.

Key Teaching Resources

Hot Deserts PowerPoint
Hot Deserts PowerPoint (easier)
Hot Deserts Worksheet
Hot Deserts Making Plants and Animals
Hot Deserts Making Plants and Animals – Info sheet
Hot Deserts homework

Teacher CPD/ Extended Reading

Hot Deserts_More for Teachers

Alternative or Extension Resources

 

Weather and Climate: a Teachers’ Guide

10. Polar Climate

Weather and Climate: a Teachers’ Guide

Pathway: Climate

Atmospheric and Oceanic CirculationClimate ZonesPast Climate Change Polar Climate

Lesson overviewIn this lesson we investigate why polar climates are so extreme and how it can be too cold to snow in Antarctica.

The extremes of Polar weather – the lowest temperatures on Earth and little precipitation – vary significantly throughout the year.  Antarctica has the harshest conditions, recording an annual mean low of nearly -60oC due to its elevation and distance from the sea.  Low levels of precipitation define Polar regions as deserts and it can be too dry to snow. The effects of climate change are amplified in these regions through feedback mechanisms which in turn affect global climate. 

Learning objectives:

  • To understand why it is cold in Polar regions.

  • To understand why our Polar regions are classified as deserts.

  • To be able to calculate mean temperature and total precipitation and interpret a climate graph

Key Teaching Resources

Polar Climate PowerPoint
Polar Climate PowerPoint (easier)
Polar Climate Worksheet
Polar Climate Worksheet (easier)
Beast from the East homework

Teacher CPD/ Extended Reading

Polar Climate – More for Teachers

Alternative or Extension Resources

 

Weather and Climate: a Teachers’ Guide