Vanishing sea ice speeds up global warming
Unravelling the Far-Reaching Impact of Shrinking Sea Ice Across Polar Regions.
REPORT CARD
ARCTIC SEA-ICE EXTENT IS SHRINKING FAST.
Arctic sea ice is an indicator of climate stability.
Today, there is about 40% less sea ice coverage at the end of the melt season than existed in the 1980s. The ice area shrank by almost half the size of the entire European Union. What was left was smaller than at any time in at least 1,000 years.
HOW HAS ARCTIC SEA ICE EXTENT CHANGED OVER TIME?
INCREASED GLOBAL TEMPERATURE MEANS LESS ARCTIC SEA ICE
CHANGING OCEAN CURRENTS
ARCTIC SEA-ICE AGE IS GETTING YOUNGER.
Thick, stable Arctic sea ice that lasts from year to year is disappearing, and thinner ice that forms and melts with the changing seasons is taking its place. In the 40 years between 1979 and 2018, for example, the proportion of Arctic sea ice at least five years old shrank by about 90 percent. Today, just two percent of Arctic sea ice is that old or older.
White ice cover reflects much of the sun’s energy back out to space. But as ice disappears, the dark ocean is exposed, absorbs more of the sun’s energy, and warms, helping to melt more snow and ice. Estimates suggest that the loss of Arctic sea ice together with reductions in snow cover over the boreal land areas will exacerbate global warming by 25 - 40% (Duan, Cao, and Caldeira, 2019, Pistone, Eisenman, and Ramanathan, 2014).
THREATS TO WILDLIFE.
AR6 SUMMARY
A Sea Ice-free Arctic is only years away.
- The area of Arctic seas covered by late-summer sea ice is shrinking by 10.5 to 15.1 percent every decade. Between 1979 and 2018, the extent of the sea ice dwindled for every month of the year.
- Arctic sea ice is getting younger and less stable, too. In the 40 years between 1979 and 2018, the proportion of Arctic sea ice at least five years old shrank from almost a third to just two percent.
- When global warming reaches between 1.5 and 2 °C, the scientists expect the Arctic to be practically sea ice-free during September in some years. If temperatures climb to between 2 and 3 °C higher, September sea ice will be mostly a thing of the past.
