The Urals

Mountains are formed by tectonic forces, volcanic activity and erosion, and they do far more than just stand there.

They help decide climates. They act as 'water towers', giving fresh water from melting snow and glaciers because they are so high. They are biodiversity hotspots (places with very many kinds of life). And often they form natural boundaries between countries.

The Ural Mountains do the last of these on the biggest scale. Stretching about 2,500 km from the Arctic Ocean to the border of Kazakhstan, they form the natural boundary between Europe and Asia.

The range has rugged slopes, caves, valleys and forests, and it is extremely rich in minerals:

• iron ore, copper, zinc, platinum, gold;
• coal, oil and natural gas;
• semiprecious stones like topaz, quartz, agate, beryl and amethyst.

Its plant life changes along its length. Coniferous taiga forests cover the western and eastern parts; deciduous forests are found in the south. Brown bears, wolves, lynx, elk, reindeer and sable live there.

In the north lies tundra: a treeless, cold plain where the soil stays frozen most of the time.

That frozen soil is called permafrost, and the chapter's description is worth remembering: it acts like a giant freezer, trapping greenhouse gases such as carbon dioxide and methane.

As global warming heats the planet, the permafrost melts and releases those stored gases, which speeds up climate change even more.