Records are falling at the top of the world.
The Arctic summer has a long way to go, but already sea ice levels over great swathes of the sprawling Arctic ocean are at historic lows (in the 40-year-long satellite record) for this time of year. The most striking declines are in the Chukchi and Beaufort seas, located above Alaska.
The melt is exceptional, but right in line with accelerating melting trends occurring as the Arctic warms.
"Every year we smash a record that we’re shocked at," said Jeremy Mathis, a longtime Arctic researcher and a current board director at the National Academies of Sciences.
By the end of May, Arctic sea ice overall was vastly diminished, running some 436,000 square miles below average. Now, the downward trend continues, with the lowest sea ice on record for mid-June.
We should get used to these Arctic records, emphasized Mathis. "The extraordinary change is a given," he said. "The Arctic is superseding any projection we had for how quickly sea ice was going to go away."
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The climate regime in the Arctic has changed sharply over the last few decades. The Arctic was once blanketed with older, thicker ice. But now the ice is younger, thinner, and easily melted.
"This is due to the long-term warming of the Arctic," said Zack Labe, a climate scientist and PhD candidate at the University of California, Irvine. "Air temperatures are now rising at more than twice the rate of the global mean temperature -- a phenomenon known as 'Arctic Amplification'."
This warm air means thinner and less hardy ice that's more susceptible to melt during the summer, noted Labe.
And with warmer air temperatures comes warmer oceans. The Arctic suffers from a vicious feedback loop, wherein the bright, reflective ice melts, and then more of the dark ocean absorbs sunlight. This drives even more melting.
"I’m running out of adjectives to describe the scope of change we’re seeing."
And the oceans in large parts of the Arctic are indeed warmer than usual, said Lars Kaleschke, a sea ice researcher at the Alfred Wegener Institute for Polar and Marine Research. Kaleschke, who has been watching the recent melting with "great interest," noted that the waters in the Pacific Arctic and parts of the inner Arctic are warmer than average. The ice is thinner there, too.
"In consequence, the thinner ice now retreats much faster than usual," said Kaleschke.
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For the many of us viewing the melting Arctic on satellite images from thousands of miles away, the rate of change in the high north can be difficult to grasp. But not for scientists like Mathis, who have traveled through these icy oceans.
"I’m losing the ability to communicate the magnitude [of change]," said Mathis. "I’m running out of adjectives to describe the scope of change we’re seeing."
Though the longer term melting trends are unmistakable, in the shorter term, like this summer, Labe noted that cooler weather patterns can still swoop in and potentially chill the region. Although ice is now at record lows in many places -- and overall is currently at the lowest point in the satellite record -- this year might not necessarily end up breaking the all-time record low, set in 2012 at summer's end.
Regardless, the big picture is clear. "The 12 lowest extents in the satellite record have occurred in the last 12 years," the National Oceanic and Atmospheric Administration (NOAA) noted in 2018.
This means a melting Arctic that's opening up for more shipping and a militarization of the region from the likes of Russia and China, explained Mathis. There's strong evidence that a warmer Arctic also perturbs global weather patterns and stokes weather extremes thousands of miles away, in heavily populated areas.
The difference today, compared to the last hundreds of thousands of years, comes down to the heat-trapping gas carbon dioxide saturating the atmosphere, noted Mathis. Atmospheric carbon dioxide concentrations are now accelerating at geologically and historically unprecedented rates.
Even if global civilization is able to slash carbon emissions and curb temperatures at levels that would avoid the worst consequences of climate change, the exceptionally warmed Arctic will still feel the heat.
"Regardless of any mitigating efforts, the Arctic is going to be a fundamentally different place," said Mathis.
