The Arctic is a place that has been particularly affected by climate change. Now a new study has shown that the Arctic is beginning to transition to 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 discovered that these fluctuations are shifting outside the expected range, towards a ” new arctic climate. “
The rate of change is remarkable. It is such a rapid period of change that past weather patterns no longer show what to expect next year. The Arctic is already entering a completely different climate than it was a few decades ago.
Laura Landrum, lead author of the study.
With the levels of sea ice reaching historic lows and the temperatures reaching record highs in recent years, the team wanted to investigate whether the Arctic was fundamentally a different climate to that of a few decades ago. To do this, they used vast amounts of data from Arctic weather conditions to statistically define the boundaries of the “old Arctic,” and they used hundreds of simulations to project conditions into the future.
The top three factors they took into account were the extent of sea ice in late summer (when it is at its lowest point annually), air temperatures in fall and winter, and when rainfall changes from mostly snow to mostly rain. .
The team applied statistical techniques to define when the typical changes in each of these three figures exceeded the natural variation. Basically, if a given 10-year average of a number was more than two standard deviations from its average in the 1950s, then it constituted a new climate.
By this reasoning, the team found that for the extent of sea ice, a new climate emerged around the turn of the century. The average September low is now 31% lower than in the decade from 1979 to 1988. If greenhouse gas emissions remain high, the team predicts that by the end of this century the Arctic could experience between three and 10 months out of the year with almost no sea ice.
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 in terms of changes in rainfall, the team found that by midcentury the rainy season will likely be 20 to 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 removed from anything we’ve ever experienced before. We have to change our definition of what the Arctic climate is.
Of course, however complete our models may be, these types of predictions are not always entirely accurate. Climate is an intricate web of factors, including those that are overlooked like algal blooms and new holes in the ozone layer, others that we underestimate, and still others that we are not aware of. Exactly how this all plays out is still debated, but with so many independent studies reaching similar conclusions, the next century will be a century of transformation for the top of the world.
More information: www.nature.com