Atop the globe, there’s probably no turning back.
Melting trends in the Arctic today are increasingly stark. The 2018 Arctic Report Card, produced by the National Oceanic and Atmospheric Administration (NOAA), depicts a thawing world that is continuing to warm and melt at an unprecedented pace.
“I think that the report demonstrated everything we’ve been seeing for the last decade,” Jeremy Mathis, a NOAA Arctic scientist who was not involved with this report, said in an interview.
“The changes in the Arctic are happening faster than they’re happening anywhere else on the rest of the planet.”
The driver of the Arctic’s vanishing sea ice is warming air. Here, the trends are clear. Air temperatures in the Arctic over the last five years have been the five highest on record, since 1900, the report emphasizes.
But in the Arctic, this warming is especially magnified.
The vast Arctic Ocean is subject to an unstoppable “albedo effect,” in which vanishing sea ice sets the stage for more melting of ice to occur, in a vicious cycle.
Specifically, bright white sea ice has a high albedo, or ability to reflect sunlight. But when the ice melts, it leaves the dark ocean to absorb heat, which then warms both the oceans and surrounding air. In turn, this melts more ice.
The consequences are clear. Sea ice is covering less and less area, commonly called “low ice extents.”
“The 12 lowest extents in the satellite record have occurred in the last 12 years,” the report underscores.
There isn’t just less Arctic sea ice — the nature of the ice has changed profoundly too. The older, strongest ice — which is more resilient to warming temperatures — is vanishing.
In 1985, the oldest ice (which is ice greater than four years old) comprised 16 percent of Arctic’s total sea ice, the report concludes. But by March 2018, the old ice made up just 0.9 percent of the Arctic’s ice, the report said.
That’s a 95 percent reduction.
“That older, thicker ice showed very clear signs of melting this year,” said Mathis.
He noted the melting of the some of the most ancient, formidable ice in the Arctic — an area of ice north of Greenland that’s about the size of Indiana.
That melting is no easy feat. This ice is, on average, 16 feet thick, and can grow to as much as 65 feet thick.
All signs point towards the reality that this trend will continue, which means an Arctic dominated by young, thin ice — ice that is all the more susceptible to today’s accelerating climate change.
Soon enough, this means an ice-free, or nearly ice-free Arctic.
“We’re headed towards an ice-free summer in the not-too-distant future,” said Mathis. “We’re on the order of a decade or two away.”
Stopping this trend, in the short term or coming decade, will be nearly impossible. This is because humanity has loaded the atmosphere with the highest concentrations of carbon dioxide — a potent greenhouse gas — in some 15 million years. It won’t simply fade away in so short a time.
What’s more, climate and economics researchers expect modern civilization to increase our carbon output over the coming decade.
But in the longer term — to stave off even more dire warming in the Arctic — the solution is simple and promoted by scientists everywhere: We must reduce our global carbon emissions in an extreme way.
An increasingly ice-free Arctic will certainly open up economic opportunities, including those for commercial shipping.
But this comes with a big cost. The Arctic, a dominant region of Earth, has sway over the greater globe.
“We know climate change in the Arctic can have a destabilizing effect on weather and climate patterns around the Northern Hemisphere,” said Mathis. “We’re going to have to pay attention to those trade-offs.”
Of note, the Arctic report card details a growing understanding of how Arctic warming has a significant effect on the jet stream, high atmospheric winds that cut directly across the United States.
A warm Arctic reduces the temperature difference between the middle-latitudes, where the lower 48 states lie, and the Arctic. This tends to dampen these winds and allows the jet stream to bend, in big waves.
There’s ever-growing evidence that this results in persistent summer-like weather patterns over the U.S., Europe, and elsewhere.
“The Arctic meltdown may also be contributing to summer heatwaves, drought, wildfires, and flooding over Northern Hemisphere continents,” Jennifer Francis, a marine scientist at Woods Hole Research Center, wrote in the report.
This weaker jet stream, pushed up higher into California, is already making for an extended, damaging fire season in California, scientists say.
“…it’s becoming ice-crystal-clear that change in the far north will increasingly affect us all,” Francis writes.
Elsewhere in the Arctic Report Card, NOAA outlines more examples of widespread change — some of it beneficial, but mostly not.
With depleted sea ice comes a boom in ocean plankton, which means more ocean creatures sucking historically high carbon dioxide out of the air. Some of these blooms of ocean life, however, are toxic.
Elsewhere, the iconic grazing animals of the high north, like reindeer, have seen their populations plummet by half. Microscopic plastic contamination is climbing in the Arctic, in some places increasing 20 times over the last decade.
Some of these changes are easier to see than others. But dramatically vanished sea ice, stoked by climate change, is an easily-visible, growing reality.
“The Arctic is a great indicator of where the global climate is headed,” said Mathis.