Researchers say that the Arctic serves as a refrigerator because its sea ice helps cool the rest of the world, but recent evidence shows that this refrigerator is facing some major issues. Climate change denial has grown increasingly popular. However, most scientists agree that perennial ice, the older ice that is able to survive in summer and help moderate climate, have seen a dramatic decline in both thickness and extent in the past three decades. These measurements—which are collected with the NASA Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E) instrument on the NASA Aqua satellite and the Special Sensor Microwave/Imager (SSM/I) instrument on the Defense Meteorological Satellite Program, the National Snow and Ice Data Center (NSIDC) reports—reveal a warming Arctic. Why do experts focus more on the Arctic than they do on Antarctica? The Arctic has more ice that lasts through summer when the ocean absorbs 90 percent of sunlight, which means it has a significant role in affecting global climate. Here are images revealing what’s happening in the Arctic and how it could affect the planet.While natural variations have contributed to changing air temperatures, Mark Serreze of the NSIDC says “. . . it’s very convincing that we’re starting to the see the effects of human activity on Arctic ice cover.”
Note that temperatures in the Beaufort and Chukchi Seas were unusually high, which limited ice growth in the Arctic region.
In addition to Beaufort and Chukchi, higher sea surface temperatures and slower ice growth were found in the Barents and Kara Seas.
Extent and area are two different measurements. The NSIDC says, “Extent would be a measure of the edges of the slice of cheese and all of the space inside it. Area would be the measure of where there is cheese only, not including the holes.” Extent will determine whether a region is “ice-covered” or “not ice-covered” based on a threshold.
The solid white indicates older, thicker ice. This is the kind of ice that can last through summer and help offset warming.
The bright white has thinned out dramatically. There are still layers of ice there, but they are much younger and thinner, meaning they are less likely to last when the ocean absorbs the sunlight.
Both terrestrial and marine animals are affected—sea ice is considered a biome in itself—and many are forced to change the way they feed and migrate.
When land ice melts, freshwater is added to the oceans. This causes sea levels to rise. Researchers say that the Greenland ice sheet has lost 140 billion tons of ice per year over the past two decades.
**Here’s a visualization of the perennial Arctic sea ice from 1980 to 2012.**
**Watch another animation of older Arctic sea ice disappearing, narrated by Dr. Walt Meier of NASA Goddard.**