The Arctic is getting wetter and stormier

As humans warm the planet, the once cold and frozen Arctic is becoming wetter and stormier, with changes in its climate and seasons forcing local communities, wildlife and ecosystems to adapt. scientists said Tuesday in an annual assessment of the region.

Even though 2022 was only the sixth-highest year of recorded heat in the Arctic, researchers have seen many new signs of the region’s change.

A September heat wave in Greenland, for example, caused the island’s ice sheet to melt the most for this time of year in more than four decades of continuous satellite monitoring. In 2021, a heat wave in August brought rain to the top of the ice sheet for the first time.

“Knowledge about the circumpolar region is more relevant than ever to the conversation about our planet’s warming,” said Richard Spinrad, Administrator of the US National Oceanic and Atmospheric Administration (NOAA). “We see the impacts of climate change occurring first in the polar regions. »

Temperatures in the Arctic Circle have risen much faster than those of the rest of the planet, transforming the region’s climate into one that is defined less by sea ice, snow and permafrost and more by open water. , rain and green landscapes.

Over the past four decades, the region has warmed four times faster than the global average, not twice or three times as often claimed, Finnish scientists said this year. According to them, parts of the Arctic are warming up to seven times faster than the global average.

Arctic communities at the front

Nearly 150 experts from 11 countries have compiled this year’s assessment of Arctic conditions, the Arctic Bulletin, which NOAA has produced since 2006. This year’s bulletin was released Tuesday in Chicago at a conference of the American Geophysical Union, the society of earth, atmospheric and ocean scientists.

According to scientists, the warming of the Earth’s surface is raising sea levels around the world, changing the way heat and water circulate in the oceans and could even influence extreme weather events like heat waves. and rain storms. But Arctic communities are the first to feel the effects.

“Our homes, livelihoods and physical safety are threatened by rapidly melting ice, thawing permafrost, increasing heat, wildfires and other changes,” said Jackie Qatalina Schaeffer, author of a newsletter chapter dedicated to local communities, who is director of climate initiatives for the Alaska Native Tribal Health Consortium and Inupiaq of Kotzebue, Alaska.

Between October and September 2021, air temperatures over Arctic lands were the sixth warmest since 1900, the report said, noting that the seven warmest years were the last seven.

Rising temperatures have favored the growth of plants, shrubs and grasses in parts of the arctic tundra, and the year 2022 has seen levels of green vegetation that were the fourth highest since 2000, notably in the Arctic. Canadian Arctic Archipelago, northern Quebec and central Siberia.

Three main factors could be behind the increase in precipitation in different parts of the Arctic, explained John Walsh, a scientist at the International Center for Arctic Research at the University of Alaska in Fairbanks, and one of the newsletter’s authors. First, warmer air can hold more moisture. Then, when the sea ice recedes, storms can suck more open water into the ocean.

According to the assessment, sea ice indicators have rebounded this year after a near decline in 2021, but are still below long-term averages. Each year, the ice is most extensive in March and lowest in September. This year, at both times, ice levels were among the lowest since satellites made reliable measurements.

The third factor is that storms pass over warmer waters before reaching the Arctic, which supplies them with energy, Walsh explained.

The remains of the typhoon Merbok crossed unusually warm waters in the North Pacific in September before hitting communities along more than 1,600 km (1,000 mi) of Alaskan coastline.

The Greenland Ice Sheet has lost ice over the past 25 years, and this year was no different. But what struck scientists was the extraordinary explosion of melting in September, the kind of event you normally see in mid-summer.

In early September, a high pressure system brought warm, humid air that pushed temperatures in parts of Greenland up to 36 degrees Fahrenheit above normal for this time of year. According to the report, more than a third of the ice cap has melted. Later in the month, remnants of the hurricane Fiona crossed the island and caused further melting of 15% of the ice sheet.