Snow & Ice
Even in a warming world, there will still be snow. But the amount of snow and when it falls is already changing. Snow cover across the Northern Hemisphere and North America are both declining, on average, with the decreases most pronounced in spring and fall. However, snow may be heavier in places where it is still cold enough to snow since a warming world also comes with more evaporation, leading to more intense precipitation.
There are regional patterns to the changing snowfall. Lake effect snow is expected to increase in the short term as the Great Lakes remain ice free longer, but by the end of the century, a warming atmosphere will likely decrease the annual amount of lake effect snow. Also, more precipitation is falling as rain instead of snow in lower elevations of the West and other parts of the country.
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. Both Antarctica and Greenland are losing ice, and the majority of the world’s land glaciers are in dramatic retreat — including those in the U.S., Europe, and the Himalayas.
Sea ice extent, while changing seasonally and not contributing to sea level rise, is also on the long-term decline. In the Arctic where the annual extent reaches its minimum at the end of the summer, its September extent is declining at a rate of 13.2 percent per decade. Also, multi-year ice is thinning, which is the sea ice that survives the summer melt season. Older ice comprised about half of the Arctic sea ice in the 1980s, while it is now less than 25 percent. In the Antarctic, where geography limits the amount of multi-year ice, sea ice extent has decreased in recent years after peaking earlier in the 2010s.
Resources for covering snow, ice and cold: