Global warming might not lead to colder winter days in the future, as scientists initially thought, according to a new study published in the UK-based Nature Climate Change.
According to the report's author, the earlier theory of Arctic amplification wrongly suggested that we will see colder winters as melting ice caps expose warmer water to the arctic air. Author James Screen writes that there's real reason to believe that what we saw this winter will consistently happen again:
Previous hypotheses linking Arctic amplification to increased weather extremes invoke dynamical changes in atmospheric circulation, which are hard to detect in present observations, and highly uncertain in the future.
There's more historical evidence to support the prediction, he says, that winter days will in fact be warmer:
In contrast, decreases in subseasonal cold-season temperature variability, in accordance with the mechanism proposed here, are detectable in the observational record and are highly robust in twenty-first-century climate model simulations.
In a press release, Screen explained that "autumn and winter days are becoming warmer on average, and less variable from day-to-day. Both factors reduce the chance of extremely cold days," adding that these days are warmer because Arctic wind is getting warmer. "Cold days tend to occur when the wind is blowing from the north, bringing Arctic air south into the mid-latitudes. Because the Arctic air is warming so rapidly these cold days are now less cold than they were in the past," he said.
Of course, warmer winters don't preclude extreme storms, which are still likely to occur more frequently in the coming years. So if this study proves true, it'd be little more than a silver lining.