Worrying signs from the Arctic

 

The Russell Glacier descending toward a lake of its own meltwater near Kangerlussuaq, Greenland, in July. Sean Gallup/Getty Images

 

By David Gelles   In a year full of troubling signs that Earth’s climate is rapidly changing, some of the most alarming signals came from the Arctic. The thawing tundra has become a source of greenhouse gas emissions, instead of locking away carbon. Sea ice levels are near historic lows. Fires are getting worse. Surface air temperatures are near record highs. And, yes, the polar bears are in trouble. “There’s a lot going on in the Arctic,” said Brendan Rogers, an Arctic scientist at the Woodwell Climate Research Center in Falmouth, Mass. “There’s big changes in the rivers, and with salmon, and big changes in the atmosphere, and with sea ice, and ocean productivity, and the fauna.” One area of particular concern to Rogers is the increase in wildfires. Fire season is getting longer, the fires are burning bigger and hotter, and more fires are being ignited by lightning strikes. “The primary reasons are all directly tied to climate change,” he said. Some fire activity is natural, of course. But Rogers said that, because of climate change, “the fires are happening too quickly, too much; they’re also increasing in severity and intensity.” Another point of acute concern: Parts of the Arctic that have long stored carbon are now turning into sources of carbon. Last week, the National Oceanic and Atmospheric Administration announced that the Arctic tundra has in recent decades been “adding more carbon dioxide to the atmosphere than it has removed, a reversal from the usual state of affairs since the peak of the last ice age,” my colleague Raymond Zhong wrote. What happens in the Arctic doesn’t stay in the Arctic A warmer Arctic has the potential to alter global weather patterns. It’s the temperature gradient between the polar regions and the Equator that drives air currents that move high and low pressure systems around the globe. Major changes to the Arctic will most likely have far-reaching consequences, though scientists can’t yet predict exactly what they will be. “There’s a lot about the Arctic that does very directly affect the rest of the world,” Zhong told me. The thawing Arctic is also shaking up geopolitics. With sea ice melting, new shipping lanes are opening up. As a result, Russia and China have sought to project their influence in the region in recent years. That has led Canada to step up its military presence in the region and seek to work more closely with the United States. Announcing the move, the Canadian government called climate change “the overarching threat” to control of its Arctic territories. Meanwhile, tensions between Russia and the West have resulted in scientists being shut out of the Russian Arctic, compromising efforts to collect reliable data on one of the largest and most significant swaths of the Arctic on Earth. It’s too early to say we’ve hit a tipping point Scientists can’t yet say that the changes being observed in the Arctic are irreversible, or that they are accelerating and compounding. And while the tundra is now a carbon source, other permafrost areas, including beneath boreal forests, are still net carbon sinks, or natural reservoirs that store more carbon than they emit. (Though the forests are burning at an alarming rate.) Still, things are moving fast up north. The Arctic is warming four times as fast as the rest of the planet. In the waters that connect the Atlantic and the Pacific Oceans in northern Canada, sea ice was the lowest ever recorded in the period from October of 2023 to September. In Canada’s Western Arctic, thawing permafrost is triggering landslides and making it a near certainty that some villages will have to move. This summer, the eastern half of Hudson Bay, home to the world’s most-studied polar bears, was ice-free a month earlier than usual. A group of scientists recently warned that the Arctic could experience its first day that is practically ice-free by 2027. And, for the 11th year in a row, the Arctic was more abnormally warm than the world as a whole. In a recent guest essay for the Times’ Opinion section, a former park ranger, Jon Waterman, revisited Arctic landscapes he first encountered 40 years ago and witnessed a world transformed by fires, landslides, new vegetation and melting permafrost. When Waterman asked a villager, sweating in the heat, what could be done about climate change, he replied, “Maybe people down south could reduce their emissions.”

Arctic Tundra Has Long Helped Cool Earth. Now, It’s Fueling Warming.

 

 

A hill with an ice core, known as a pingo, in the Mackenzie River Delta, Northwest Territories. Credit...Renaud Philippe for The New York Times

 

 Wildfires and thawing permafrost are causing the region to release more carbon dioxide than its plants remove, probably for the first time in thousands of years.

By Raymond Zhong

 

For thousands of years, the shrubs, sedges, mosses and lichens of the Arctic have performed a vital task for the planet: gulping down carbon dioxide from the air and storing the carbon in their tissues. When the plants die, this carbon is entombed in the frigid soil, where it no longer helps warm Earth’s surface.

But as fossil fuel emissions heat the planet, balmier air temperatures are thawing Arctic tundra, activating carbon-hungry microbes, and more vegetation is being burned up by wildfires.

The result, for the past two decades or so, is that the tundra has been adding more carbon dioxide to the atmosphere than it has removed, a reversal from the usual state of affairs since the peak of the last ice age.

It’s one of many signs of rapid change in the National Oceanic and Atmospheric Administration’s Arctic Report Card, the agency’s yearly checkup on the polar region. The 2024 report card was issued on Tuesday in Washington at the annual meeting of the American Geophysical Union, an association of earth and space scientists.

                                   Arctic Methane Release

 

 For the 11th year in a row, the Arctic this year was more abnormally warm than the world as a whole, the report card said. The period from October 2023 to September was the second-warmest for the region since 1900. In the Northwest Passage, the sea route that links the Atlantic and the Pacific through the islands of northern Canada, the area covered by sea ice this summer was the lowest since records began. Parts of Arctic Canada had their shortest snow season on record.

“The Arctic today, year after year, looks vastly different than the Arctic did 20 years ago,” said Twila Moon, an editor of the report card and the deputy lead scientist at the National Snow and Ice Data Center in Boulder, Colo.

In the Arctic tundra, there have long been signs of a shift in how much carbon is moving between the land and the air. But by incorporating more data and better methods of analysis, scientists can now describe the trend with confidence: Between 2001 and 2020, wildfires and thawing permafrost caused the tundra to release more carbon dioxide than its plants removed from the air, probably for the first time in many millenniums.

How much this gap widens depends in large part on how much nations rein in greenhouse warming, said Brendan Rogers, an Arctic scientist at the Woodwell Climate Research Center in Falmouth, Mass., who contributed to the report card.

“The more we can do to lower the overall temperature changes globally, the better we’re going to be able to deal with permafrost emissions,” Dr. Rogers said.

Gathering data in the vast Arctic environment is always a challenge, but Russia’s war in Ukraine has compounded the difficulties, including for scientists assessing the carbon cycle. “There are large parts of Siberia that we just don’t have any data from,” Dr. Rogers said.

Not all of the news in this year’s report card was bad.

In the seas around Alaska, ice seal populations challenged by rising temperatures were deemed healthy. And a cool winter helped Greenland’s vast ice sheet shed the smallest volume of ice since 2013, around 55 billion tons, though the long-term trend is still that melting ice from the island is adding enormously to rising sea levels worldwide.