EXPLAINED IN 54 SECONDS
WHAT IT IS
Land ice in the form of glaciers and ice sheets contains the majority of the world’s fresh water and covers about 10 percent of the world’s land area. Every continent but Australia has some amount of land ice, but the large majority of it exists on Greenland and Antarctica. According to NASA satellite images, both Antarctica and Greenland are losing ice, with the Antarctica losing more than 24 cubic miles of land ice per year since 2002. But other areas have also seen recent dramatic glacial retreat, including Mount Kilimanjaro (which lost about 80 percent of its glacial ice in the past century), Alaska and the Himalayas.
WHY IT'S IMPORTANT
The melting of land ice contributes to sea level rise by adding water to the oceans. Additionally, nearly one-sixth of the world’s population – including in South America and Central Asia – rely on glacial runoff for fresh water, and a loss of glaciers leads to a decrease in runoff. Greenland and Antarctica alone contain 75 percent of the world’s fresh water, and if they melted entirely, sea levels would rise by 75 meters. Like sea ice, land ice is also highly reflective, so that its melting increases absorption of solar energy and thus enhances global warming in a feedback loop.