Arctic Sea Ice Near Record Low Extent
After last week’s celebration of local climate stories, we’re returning to a key global topic: the warming Arctic. This summer, temperatures in Alaska shattered records while hundreds of wildfires burned across the region. And Arctic sea ice extent was running at a record low as recently as August 9th. While the melting has slowed somewhat, a near-record minimum for the year is expected to be announced soon.
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Sea ice has an annual freeze and melt cycle at both poles. The summer melt culminates in September for the Arctic, and in early March for the Antarctic. But as the climate warms, the minimum ice extent is shrinking, particularly in the Arctic:
Since 2002, every Arctic minimum has been below the long-term average (1981-2010).
The ten lowest years have all come since 2007.
Arctic ice extent minimums are declining by 12.8% per decade.
The ice is also thinning, making it more fragile: more than 70% of Arctic ice is now seasonal as compared to thicker, multi-year ice; and only 1% is more than four years old—an eighteen-fold drop since 1985.
Ice loss is leading to a dangerous heat spiral. When ice cover melts and exposes the ocean, the ocean absorbs more heat in a self-feeding cycle. This contributes to the Arctic warming twice as fast as the rest of the planet, which affects local communities and wildlife. But what happens in the Arctic doesn’t stay in the Arctic. When polar permafrost thaws, even more greenhouse gases are released—warming the planet at an accelerating pace. Recent research suggests that long-established weather patterns may be changing as well, potentially leading to more persistent or extreme conditions in the United States. And while sea ice decline does not contribute to sea level rise, Greenland contains enough land ice to raise global sea levels by 20 feet. Reducing our collective carbon footprint—the focus of Monday’s United Nations Climate Action Summit—can help avoid these worldwide changes.
|Full Release: Melting Ice Fuels Heat Spiral||Graphic: Why It Matters|
For more details, check out:
Tools galore from the National Snow & Ice Data Center: rankings, animations, and detailed documentation
NASA’s Arctic sea ice minimum page from the Vital Signs of the Planet and other visualizations
NOAA’s Annual Arctic Report Card
METHODOLOGY: All graphics use Arctic ice data from the National Snow and Ice Data Center. This year’s data for the minimum ice extent and volume were not available before this release, but are expected in September.