Challenging environments

Global distribution of extreme environments

• Explain the global distribution of each of the two kinds of extreme environment.
• Describe the relief and climatic characteristics that make these environments extreme.
• Explain how these characteristics present challenges for resource development and human habitation.

There are two main types of extreme environment – cold and high altitude, and hot and arid.

Cold and high altitude

Contain: polar (areas near the north and south pole), glacial (areas with dense bodies of ice) and periglacial (boundary areas) regions.

• Their distribution is very uneven across the globe.
• Polar environments are located around the North and South pole due to the low levels of insolation
• There is a belt of periglacial environments in the Northern hemisphere, and a lack of one in the Southern hemisphere (due to lack of land).
• Other cold environments are located at high altitudes, e.g the Himalayas or the Andes.
• Temperatures above 6 degrees celsius for only a few months of the year.
• The ground is often steep, with thin and infertile soils.

Cold environments with snow covered ground often stay cold due to their high surface albedo. Albedo is the ability of a surface to reflect the suns radiation. Snowy areas with cloud cover have a very high albedo.

Hot and Arid

Contain: desert areas ( a sever lack of annual rainfall) and semi-arid areas (moderate lack of rainfall – less than 50cm yearly)

• Hot climates can be observed between pockets in the convectional currents of the Earth’s atmosphere (Hadley Cells)
• Mainly found in high pressure conditions.
• These areas often have an overall lack of water
• High temperatures throughout the year
• Frequently have mountain ranges nearby which provide the conditions necessary for rain-shadow to occur.

Many hot and arid environments are located in rain-shadows. These are regions that have little rainfall as they are sheltered from prevailing rain-bearing winds by mountains.

 

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Population

• Explain the other factors responsible for a low density of population in these areas; human discomfort, inaccessibility, remoteness.
• Identify ways in which people adapt their activities to extremes of weather and climate.

Extreme Environments often have a low population density – this is due to a multitude of factors:

• Human discomfort – very hot climates and very cold climates often have temperatures that lie outside of 15-25 degrees celsius, which is not ideal for human habitation.
• Inaccessibility and Remoteness – periglacial environments can be surrounded by steep terrain that is difficult for humans to navigate. Likewise, arid environments can be land-locked and located far from navigable oceans and seas.

In order to cope with living in these environments, humans have had to adapt to their conditions.