The lack of moisture in a desert makes it tough for life to survive. Deserts can be hot, like the Sahara in Africa, or cold, like the Dry Valleys in Antarctica. Click on image for full size (61 Kb)

This page describes environments that are very hot or very cold, extremely dry, or both. Extreme environments are places that are inhospitable to most "normal" living creatures. Extreme environments are not necessarily lifeless. Certain types of organisms, known collectively as "extremophiles", have adapted to survive or even thrive in various types of extreme environments.

Familiar extreme environments include deserts, mountain peaks, caves, and the frozen realms of the Arctic and Antarctic. Some extreme environments are acidic or alkaline, are exposed to high levels of radiation, are under tremendous pressure, or are otherwise hostile to "normal" life.

Many environments are too hot or cold for most living creatures. The extreme heat of deserts like the Sahara in Africa and Death Valley in North America makes survival challenging in such locales. Less familiar hot environments include the scalding waters that issue forth from hydrothermal vents in the ocean floor and from geysers and hot springs in places like Yellowstone National Park in the USA.

On the other end of the scale, extremely cold environments can also be hostile to most life forms. This of course includes the ice caps, snow fields, and sea ice found in the Arctic and Antarctic, as well as similarly chilly niches high on mountaintops worldwide. The deep oceans are also quite cold; temperatures in the 90% of ocean water that lies beneath the thermocline hover between 0° and 4° C (32° and 39° F).

Water shortages can also make it difficult for life to get by. Deserts are famously dry, though not all of them are hot. Antarctica is actually Earth's largest desert, and the Dry Valleys there are among the driest places on our planet. Some locations in Chile's Atacama Desert receive less than 1 millimeter (0.04 inch) of rainfall per year on average, and can go decades without any rain at all.

This picture shows sand dunes in a desert. Deserts are very dry. They are one kind of extreme environment. It is hard for most living creatures to survive with so little water. Some deserts are hot, like the Sahara in Africa. Others are cold, like the Dry Valleys in Antarctica. Click on image for full size (61 Kb)

This page describes environments that are very hot or very cold, extremely dry, or both. Extreme environments are places where "normal" life finds it hard to survive. That doesn't mean that there isn't any life in extreme environments. Certain creatures can live and grow in extreme environments. Scientists have a special name for creatures that live in extreme environments. They are called "extremophiles".

What kinds of environments are "extreme"? Some extreme environments that you may know about are deserts, mountain peaks, caves, and frozen places like the Arctic and Antarctic. Some other examples of extreme environments are places that are filled with acids, are blasted with radiation, or are under high pressure.

Many environments are too hot or too cold for most living creatures. The heat in deserts like the Sahara in Africa and Death Valley in North America makes it hard for life to survive there. What are some other hot environments that you may not know about? Hydrothermal vents in the ocean floor spew out very, very hot water. Geysers and hot springs in places like Yellowstone National Park in the USA also contain water that is too hot for most living creatures.

Really cold environments are tough on life too. The ice caps, snow fields, and sea ice found in the Arctic and Antarctic are examples of cold environments. High mountaintops around the world are also usually quite chilly. The deep oceans are not quite frozen, but they are still pretty cold, too. About 90% of ocean water is below a level called the thermocline. Water below the thermocline has a temperature between 0° and 4° C (32° and 39° F).

Places that are very dry are also extreme environments. The lack of water in deserts is hard on life. Many deserts are both very hot and very dry. Did you know that some deserts are cold instead of hot? Antarctica is actually Earth's largest desert! The Dry Valleys in Antarctica are some of the driest places on our planet. How dry can deserts be? Some places in the Atacama Desert in Chile get an average of less than 1 millimeter (0.04 inch) of rainfall a year! Sometimes many years go by there with no rain at all.

This picture shows sand dunes in a desert. Deserts are very dry. They are one kind of extreme environment. It is hard for most living creatures to survive with so little water. Some deserts are hot, like the Sahara in Africa. Others are cold, like the Dry Valleys in Antarctica. Click on image for full size (61 Kb)

This page describes environments that are very hot or very cold, really dry, or both. It is easy for living creatures to survive and grow in some places. Other places make it tough for life to get by. Scientists call places that are hard on life "extreme environments".

What kinds of places are "extreme environments"? Some that you may know about are deserts, mountain peaks, caves, and frozen places like the Arctic and Antarctic. Some extreme environments are filled with acids, are blasted with radiation, are under high pressure, or are tough places for most living things in other ways.

Just because an environment is extreme doesn't mean there is no life there. Certain creatures can live and grow in extreme environments. Scientists have a special name for creatures that live in extreme environments. They are called "extremophiles".

Many environments are too hot or too cold for most living creatures. The heat in deserts like the Sahara in Africa and Death Valley in North America makes it hard for life to survive there. Are there other hot environments that you may not know about? Hydrothermal vents in the ocean floor spew out very, very hot water. Geysers and hot springs in places like Yellowstone National Park in the USA also contain water that is too hot for most living creatures.

Really cold environments are tough on life too. The ice caps, snow fields, and sea ice found in the Arctic and Antarctic are examples of cold environments. High mountaintops around the world are also usually quite chilly. The deep oceans are not quite frozen, but they are still pretty cold, too. Water in the deep parts of the ocean has a temperature between 0° and 4° C (32° and 39° F).

Places that are very dry are also extreme environments. The lack of water in deserts is hard on life. Many deserts are both very hot and very dry. Did you know that some deserts are cold instead of hot? Antarctica is actually Earth's largest desert! The Dry Valleys in Antarctica are some of the driest places on our planet. How dry can deserts be? Some places in the Atacama Desert in Chile get an average of less than 1 millimeter (0.04 inch) of rainfall a year! Sometimes many years go by there with no rain at all.