The Arctic is one place that’s been hit particularly hard by climate change. Now a new study has shown that the Arctic is beginning to transition into an entirely new climate state, leaving its predominantly frozen state behind.

While the Arctic has been characteristically cold for thousands of years, there are of course natural fluctuations within a certain range. But now, scientists at the National Center for Atmospheric Research (NCAR) have found that these fluctuations are moving out of the expected range, towards a “new Arctic” climate.

“The rate of change is remarkable,” says Laura Landrum, lead author of the study. “It’s a period of such rapid change that observations of past weather patterns no longer show what you can expect next year. The Arctic is already entering a completely different climate than just a few decades ago.”

With sea ice levels hitting record lows and temperatures hitting record highs in recent years, the team wanted to investigate whether the Arctic was fundamentally a different climate than it was just a few decades ago. To do so, they used large amounts of observational data of Arctic climate conditions to statistically define the boundaries of the “old Arctic” range, and used hundreds of computer simulations to project conditions forward.

Graphs of changes in the three factors the team modeled – minimum sea ice extent, surface temperature and number of rainy days. The colored sections are the ranges expected in the “old Arctic” climates, while the lines indicate past averages and projected averages in future.

The models suggest that air temperatures over the ocean will enter a new climate by 2050, with air temperatures over land following in the second half of the century. And for precipitation changes, the team found that by mid-century the rainy season will likely be between 20 and 60 days longer, and up to 90 days longer by 2100.

“The Arctic is likely to experience extremes in sea ice, temperature, and precipitation that are far outside anything that we’ve experienced before,” says Landrum. “We need to change our definition of what Arctic climate is.”

https://newatlas.com/environment/new-arctic-climate-state/