A University of Exeter climate change study shows that Arctic amplification (the faster rate of warming in the Arctic compared to places further south) reduces the risk of cold extremes across large swathes of the Northern Hemisphere.
Dr Screen, a Mathematics Research Fellow at the University of Exeter, said: "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."
In his study, Dr Screen examined detailed climate records to show that autumn and winter temperature variability has significantly decreased over the mid-to-high latitude Northern Hemisphere in recent decades.
He found that this has occurred mainly because northerly winds and associated cold days are warming more rapidly than southerly winds and warm days.
Dr Screen said: "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."
(Score: 1, Interesting) by Anonymous Coward on Saturday June 21 2014, @07:45AM
Less extreme cold in spring / fall implies a larger % of year for insects for reproduction and less opportunities for spontaneous death due to late spring freezing. Expect mosquito pop's to rise in 2015 for mid-atlantic and the correlated rise in malaria.
(Score: 2, Insightful) by Horse With Stripes on Saturday June 21 2014, @09:46AM
The birds will not need to fly as far south which will help with warming areas deal with some of the increased population. This will allow the insect populations to rise in the brids' normal winter homes. Yes, it's just moving part of the problem.
(Score: 2) by Oligonicella on Saturday June 21 2014, @12:48PM
Not really. This won't occur in one year and if the birds are slowing their migration, the population left behind can increase to feed on the greater insect population.
(Score: 2) by khallow on Saturday June 21 2014, @04:33PM
From 0% to 0%? That's at least double! Here's a clue. If there's malaria in the mid-Atlantic US, it's because the US completely fell apart and people are eating each other in DC, not because of global warming.
(Score: 2) by broken on Sunday June 22 2014, @04:01AM
I don't think mosquito populations are affected so much by season length. Even in Alaska, there are areas with serious mosquito problems. This page [alaskatrekker.com] claims that "Alaska Mosquitos Are Everywhere" and "Alaska's mosquito population is the stuff of legend." Wikipedia mentions this disturbing fact [wikipedia.org]:
This is about 2/3 of a typical whole blood donation of 470ml.
As temperatures warm, fewer frosts will allow certain inspect species to overwinter farther north than in the past, and mosquitoes may be active for more of the year, but I don't think there will be more mosquitoes at any given time unless changing temperatures also increase rainfall, which would increase breeding opportunities.
(Score: 2) by Dunbal on Saturday June 21 2014, @10:40AM
"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."
Dear Mr. Theorist: I believe you have confused cause and effect and have them backwards. A spate of fewer "extremely cold days" will certainly affect the average. But the "average" does not generate weather, being a theoretical human construct. Especially when the "average" in question is a fraction of a degree or so. If you don't believe me all you have to do is wait.
(Score: 1) by Hawkwind on Saturday June 21 2014, @05:13PM
(Score: 0) by Anonymous Coward on Sunday June 22 2014, @09:01AM
What's this, Climate change for dummies?