More rain than snow expected in Arctic earlier than thought, study says

(CNN) — Rain fell on the summit of Greenland instead of snow for the first time on record in August as the Northern Hemisphere experienced warmer-than-usual summer temperatures. A new study suggests that’s likely to be the norm in just four or five decades.

Parts of the Arctic are expected to experience more rain than snow some time between 2060 and 2070, marking a major transition in its precipitation patterns as the climate crisis jacks up temperatures in the region, according to the study published Tuesday in the journal Nature Communications.

New climate modeling shows the transition could happen earlier than scientists had previously projected. Michelle McCrystall, the lead author of the study and climate researcher at the University of Manitoba in Winnipeg, told CNN that earlier modeling suggested it wouldn’t occur until between 2090 and 2100.

“But with the new set of models, this actually has been pushed forward to about between 2060 and 2070, so there’s quite a jump there by 20 years with this early transition,” she said.

AP Photo/Alastair Grant

A droplet of water falls from a four-ton block of ice, originally part of a larger glacier, brought from Greenland to Glasgow, Scotland, for the COP26 U.N. Climate Summit. Climate scientists brought it from Arctic Basecamp as a statement to world leaders of the scale of the climate crisis and a visible reminder of what Arctic warming means for the planet.

A separate study published last week showed the Arctic Ocean had been warming for decades earlier than previously understood, which has alarmed some scientists as it suggests that the modeling they rely on to predict ocean temperature changes could be flawed.

In August, the U.N.’s Intergovernmental Panel for Climate Change published its authoritative report that concluded the planet is quickly approaching 1.5 degrees Celsius above pre-industrial temperatures — a threshold scientists say the world should stay under to avoid the worst consequences of the climate crisis. But the authors of Tuesday’s study said the transition from snow to rain will likely occur in some parts of the Arctic, particularly Greenland, even if warming is contained to 1.5 degrees.

An analysis by Climate Action Tracker of the world’s current policies showed that the Earth is currently on track for 2.7 degrees Celsius of warming. That’s assuming countries will follow through with their plans to reduce greenhouse gas emissions. At around 3 degrees of warming, researchers found that most areas in the Arctic will transition to a rainfall-dominated regime.

“If we did stay within this 1.5-degree world, the Arctic could remain snow-dominant by the end of the century, but some parts probably still will transition,” and some of them are already transitioning, McCrystall said. “But we are still on the trajectory of a 3-degree world.”

Though scientists not involved with the study overwhelmingly agreed that the Arctic is undergoing rapid change amid the climate crisis, some expressed caution about the study’s results and specifically pointed to the critical need for more observations and more research.

7 billion tons of water

The study notes that the increase in rainfall is due in large part to the loss of sea ice. More open water and warmer air temperatures mean more evaporation, priming the atmosphere for a wetter Arctic.

The study’s researchers say a rainfall-dominated Arctic has the potential to destabilize Greenland’s ice sheet mass balance, triggering a global rise in sea levels.

Scientists have concluded that the burning of fossil fuels led to Greenland melting over the past two decades. A recent study published in the journal Cryosphere found Earth has lost a staggering 28 trillion tons of ice since the mid-1990s, a large portion of which was from the Arctic, including the Greenland ice sheet.

The region already saw a preview of its rainy future last August, when temperatures at the Greenland summit rose above freezing for the third time in less than a decade. The warm air fueled an extreme rain event that dumped 7 billion tons of water on the ice sheet, enough to fill the Reflecting Pool at the National Mall in Washington, D.C., nearly 250,000 times.

Global leaders gathered in late October and early November at the 26th U.N. Climate Change Conference, known as COP26, to discuss urgent action to combat a rapidly warming world. Here are some memorable quotes from heads of state and government and others at the two-week conference in Glasgow, Scotland: