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Extreme Environments

Characteristics of Extreme Environments

The polar regions and hot arid areas both come under extreme environments because of their unique characteristics. Polar regions are located in areas of high latitude, whereas arid areas cover more latitudes but are mostly located in the tropics.

Polar Climates

  • The high latitudes mean that it is extremely cold, and the further north, the more extreme the cold.
  • Winters are very cold, up to -50oC with few or no hours of lights
  • Summers are short with many hours of light; this is the growing season in the tundra
  • Dry with less that 300 mm of precipitation per year falling mostly as snow
  • The coldest glacial regions support no life at all.
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Hot Arid Climates

  • Cold night temperatures because there aren't many clouds to retain heat
  • Hot day temperatures, often above 30oC
  • Occasional intense downfalls of rain can cause flash flooding
  • There is very little seasonal change in very arid areas
  • Not many plant, animal and human life can be supported by the hottest arid environments
  • Dry - some years may receive less than 250 mm of precipitation.
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Variations in Extreme Environments

You are likely to find variation in extreme environments, examples of these are:
  • Glacial = ice-covered - e.g.: Greenland
  • Tundra = frozen soil - e.g.: Alaska
Hot Arid
  • Deserts = less than 250 mm rain per year - e.g.: Sahara
  • Drylands = 250-500 mm rain per year - e.g.: Sahel

Why are extreme environments fragile

The unique and extreme conditions make these polar and hot arid areas very fragile, however plants and animals have been able to adapt to live in them.

Polar flora and fauna Hot arid flora and fauna
Glacial Regions
  • Only able to support very little life other than some insects, arachnids and mice.
  • Some hardy plants grow close to the ground to survive the strong winds.
Tundra Regions
  • More animals, insects and birds are able to adapt to Tundra regions compared to glacial regions. They have adapted to survive the cold with thick layers of fat and/or fur. Many of them are also coloured white to camouflage themselves against the white snow.
  • Boggy conditions suit water-loving plants such as sedges and moss.
 Semi-arid regions
  • The animals found in these regions are able to store water in fat and tend to be nocturnal, spending the day underground out of the Sun.
  • Insects collect moisture from the air.
  • Some animals have characteristics which allow them to dissipate heat easily. E.g.: large ears.
  • Plants store water (acacia trees) and/or have deep roots to reach water which is stored deep underground
  • Seeds can stay dormant for years, and when they receive rain, they are able to produce brightly coloured flowers to attract insects immediately.
Very arid regions are unlikely to have much plant or animal life
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People and extreme climates

People are able to adapt to the harsh environments of the extreme polar and arid areas. These people who live in these environments often have their own special cultures.

Polar environment - human adaptationsHot arid environment - human adaptations
  • Adaptations to the cold
    • Triple glazing in houses
    • Wear layers, wool, fur etc. to keep warm
    • Use of geothermal power.
  • Adaptation to frozen ground
    • Houses raised up above ground
    • Hunting rather than growing crops.
    • Roads built on gravel to prevent them cracking with solifluction.
  • Adaptations to the snow
    • Steep roofs so snow falls off easily.
  •  Adaptations to the heat
    • Buildings painted white to reflect the heat
    • Thick walls and small windows to keep the heat out.
    • Air conditioning in homes
    • Wearing loose-fitting clothes.
    • Wearing head coverings
  • Adaptations to the lack of water
    • Flat roofs to catch water
    • Irrigation used to grow crops
    • Nomadic farming so areas aren't overgrazed by herd.s.

Threats to extreme climates

Although climate change is one of the main threats to extreme environments, there are also other factors which could damage them, mainly caused by humans.

ThreatImpact in Alaska (polar region) Impact in Sahel (arid region) 
PollutionOil spills, such as the Exxon Valdez, have caused environmental catastrophes in the pastThe threat of drought may increase by rising levels of air pollution from newly emerging economies and industrialised countries. 
Land degradationPermafrost melting due to buildings heating up land, especially around big urban centres.Desertification leads to disappearing vegetation and soil erosion. It is partly caused by overgrazing of live stock.
Cultural dilution
Loss of native languages and cultural traditions from the growing influence of Western cultures Traditional rituals performed to entertain tourists. Western cultures are beginning to have a strong influence.
Out-migrationThe lack of social and employment opportunities is resulting in many people, especially the young, moving away.The lack of opportunities is resulting in people, especially the young, moving away.

The threat of Climate Change

While the whole world is at threat to the effects of Climate Change, extreme environments are very vulnerable because of how fragile their ecosystems are.

In polar environments, climate change can lead to...
  • a build up of melt water can cause lakes to burst their banks, resulting in flood water destroying ecosystems
  • Solifluction - in Tundra regions, large areas of soil melt and move like a landslide destroying vegetation in its path.
The effects of climate change in polar environments...
  • Warmer Summers
    • Changes in sea ice cover
    • Glacier Retreat
    • Permafrost melting
    • Species Migration
  • Sea level rises
    • Coastal flooding
    • Erosion
    • Ecosystem changes
  • All these effects will most likely impact upon humans, also causing...
    • coastal towns and industry to be threatened
    • life being more uncertain
    • people more likely to move away
In hot arid environments, climate change can lead to...
  • extreme drought which the most adapted animals & plants can survive
  • desertification - where the area of desert increases. Animals which used to be able to live in what used to be semi-arid areas cannot adapt and unfortunately die.
The effects of climate change in hot arid areas...
  • Less rainfall
    • dryland changes to desert (desertification)
    • reduction in grazing for livestock
  • Less reliable rainfall
    • drought problems made worse
    • possibility of intense storms increasing soil erosion
  • All these effects will most likely impact upon humans, also causing
    • Famine and conflict
    • Migration

Sustainable management

In order for extreme environments to survive, there needs to be some sustainable management.
Sustainable management...
  • makes sure an environment can recover quickly from any use
  • prevents damage to the environment
  • helps local people get benefit from their environment
  • helps local people understand the benefits.
Sustainable management in hot arid regionsSustainable management in polar regions 
In the poorer areas of hot arid regions (e.g.: Tanzania, Africa) water management is very challenging. Large-scale projects are normally too expensive and often will not meet the need of the local people. The most suitable and sustainable solutions for these areas involve intermediate technology such as...
  • Lining wells with concrete to avoid sewage contamination.
  • Hand pumps pump water up from deeper underground and the top of the well can be capped with a concrete cover to prevent contamination.
  • Water is stored in rain barrels for later use.
Sustainable management...
  • Use geothermal power where available
  • Have conservation zones to protect Arctic fauna and flora
  • Promote native cultures
  • Protect the environment fro pollution
  • Promote ecotourism
  • Fish farming as sustainable alternative to commercial trawling

Global Management
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There have been global actions which have been taken to protect extreme climates from climate change.

1997 - Kyoto Treaty
  • Commitment to reduce greenhouse gas emissions by 2012
  • Problems - The US and China didn't sign up so all reduction made by other countries were wiped out.
2009 - Copenhagen Accord
  • 190 countries agreed to limit global warming.
  • Problems - Only agreed to make plans, many had hoped for a binding agreement that would ensure countries stuck to tough limits.
2010 - Cancun Agreements
  • Funds to help develop clean technology and developing countries cut emissions.
  • Problems - Only agreed to make plans, many had hoped for a binding agreement that would ensure countries stuck to tough limits.
2011 - Durban Agreement
  • 190 countries (including US and China agree to legally binding emissions cutting targets.
  • Problems - Doesn't come into force until 2020, when many fear it will be too late.

Agreements - polar regionsAgreements - arid regions 
1961 - Antarctic Treaty
Restricts commercial development
1998 - Protocol Environmental Protection
Extended Antarctic Treaty with rigorous protection.
- No new activities allowed in Antarctica unless very low impact
UN Convention to Combat Desertification
- Since 1994 it aimed to combat land degradation, reduce poverty and develop sustainable solutions.
- Promotes 'bottom-up' solutions: local people get funding and advice
-  195 countries agreed to give money, share information and act together.