Crumbling cryosphere

On average, the global cryosphere – all of the areas with frozen water on Earth – shrank by about 87,000 square kilometres (an area larger than Austria) per year between 1979 and 2016 as a result of climate change. The study, by the American Geophysical Union, is the first to consider the entire extent of the cryosphere and the impact of climate change on it.

The cryosphere holds almost threequarters of Earth’s fresh water, and in some mountainous regions, dwindling glaciers threaten local drinking-water supplies. The land cover of ice is also important because the bright white surface reflects sunlight, effectively cooling the planet.

‘The cryosphere is one of the most sensitive climate indicators and the first one to demonstrate a changing world,’ said lead author Xiaoqing Peng, a physical geographer at Lanzhou University. ‘Its change in size represents a major global change, rather than a regional or local issue.’