Numerous media outlets cited last week’s polar vortex as an example of extreme weather caused by climate change, but it turns out such cold snaps are actually on the decline.
Roy Spencer, principal research scientist at the University of Alabama in Huntsville, posted a graphic of November-March cold waves in the East and Midwest dating back to 1895 that flies in the face of the “global warming causes extreme cold” argument.
The theory has it that the decline of Arctic sea ice, which has dropped by about 15 percent over the last 40 years, has disrupted the polar vortex, causing it to move southward, but the data assembled by Mr. Spencerand UAH professor of atmospheric science John Christy showed otherwise.
“As can be seen in the plot below, there is no evidence in the data supporting the claim that decreasing Arctic sea ice in recent decades is causing more frequent displacement of cold winter air masses into the eastern U.S., at least through the winter of 2017-18,” Mr. Spencer said Thursday on his Global Warming blog.
Not only that, but “[t]he trend is markedly downward in the most recent 40 years (since 1979) which is the earliest we have reliable measurements of Arctic sea ice from satellite microwave radiometers (my specialty),” Mr. Spencer said.
The analysis focused on cold waves in 27 Midwestern and Eastern states lasting more than two days and featuring temperatures below the 5th percentile of daily January maximums. – READ MORE