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Antarctica is the coldest, windiest and driest continent on Earth. It may seem strange to call a place covered in ice a desert, but deserts are defined by how little rain or snow they receive, not by their temperature. Large parts of the Antarctic interior receive less than fifty millimetres of precipitation a year, about as little as many hot deserts.
The continent is covered by an enormous ice sheet that is, on average, almost two kilometres thick. This ice contains about ninety percent of all the ice on Earth and around seventy percent of the planet's fresh water. If it all melted, global sea levels would rise by many metres, although scientists stress that this would take thousands of years.
Temperatures in the interior are extreme. The lowest air temperature ever directly measured on Earth, minus 89.2 degrees Celsius, was recorded at the Russian research station Vostok in 1983. Even the coast, where most wildlife lives, can experience powerful winds that make conditions dangerous for humans.
Despite this harsh environment, Antarctica supports remarkable wildlife, almost all of which depends on the rich seas around it. Tiny shrimp-like creatures called krill form the basis of the food chain and are eaten by fish, seals, penguins and whales. The emperor penguin is particularly well adapted. It breeds during the dark Antarctic winter, and after the female lays a single egg, the male balances it on his feet for about two months, eating nothing, while the females feed at sea.
No humans live in Antarctica permanently. Instead, it is home to research stations run by many countries, where a few thousand scientists and support staff live in summer and far fewer during the winter. The continent is governed by the Antarctic Treaty, signed in 1959 by twelve countries and since joined by many more. The treaty reserves Antarctica for peaceful purposes and scientific research and forbids military activity there. A later agreement, signed in 1991, also banned mining.
Today, scientists are particularly concerned about how climate change is affecting the continent. Some parts of Antarctica, especially in the west, are losing ice faster than before, contributing to rising sea levels around the world. Research carried out there is therefore important not only for understanding Antarctica but for predicting the future of coastal cities thousands of kilometres away.