The Arctic Tundra Used to Store More Carbon Than It Released. Not Anymore.

It has long been clear that the polar regions are warming at a faster rate than the rest of the planet. For decades, “twice as fast” was the refrain, but it’s worse than that: a 2022 study pegged the number at four times as fast as the average. The changes to Arctic and Antarctic ecosystems this rapid warming is causing are, at the risk of understatement, alarming.

“Our observations now show that the Arctic tundra, which is experiencing warming and increased wildfire, is now emitting more carbon than it stores, which will worsen climate change impacts,” said NOAA administrator Rick Spinrad, in a press release accompanying the 2024 Arctic Report Card, the agency’s annual look at what is happening in the far north. These are always grim exercises these days, of course; but that shift from sink to source is disturbing.

A big part of this is the increasing wildfires in the region. Since 2003, the report card found, “circumpolar” wildfires have averaged 207 million tons of carbon dioxide emissions per year, around the annual emissions of Pakistan or the United Arab Emirates. “This is yet one more sign, predicted by scientists, of the consequences of inadequately reducing fossil fuel pollution,” Spinrad said.

The report card presents a litany of horrors. The average air temperature in the Arctic were the second-warmest since 1900; the past nine years are the nine warmest in recorded history, mirroring the global trend; this past summer was the wettest such season the Arctic has ever seen. Caribou populations have declined by 65 percent over the past two to three decades; only some populations show any signs of recovery.

Off of land, things are no better. Though this summer’s sea ice extent did not break records, it’s not far off: the September sea ice was the sixth-lowest in the 45-year record, and all 18 of the lowest September minimums have occurred in — you guessed it — the last 18 years.

Along with being a CO2 source, the Arctic is also a methane source, the more potent though shorter-lived greenhouse gas. In Alaska, the permafrost — the long-frozen ground that is itself an incredibly dangerous potential source of methane — saw its second-warmest temperatures on record.

“Many of the Arctic’s vital signs that we track are either setting or flirting with record-high or record-low values nearly every year,” said Gerald Frost, a senior scientist with Alaska Biological Research who has worked on many Arctic Report Cards. As I’ve written about plenty of times before: the records falling is the norm now. When they don’t, that’s the outlier. Records don’t mean what they used to.

“The Arctic environment of 2024 is already dramatically changed from decades past and change will continue for decades to come,” the Report Card authors wrote in an introduction. “Only the strongest actions on mitigating heat-trapping gas emissions, with almost all human-produced emissions created outside of the Arctic, will allow us to minimize risk and damage into the future.”