Today, as the Chattanooga area joins a huge chunk of the country bracing against record-setting cold temperatures, many of us are shaking our heads and wondering what's up with the weird weather.
Some may even be making jokes: So much for global warming.
Don't be fooled. Global warming — more correctly labeled climate change — is not just about warming. It's about extremes. Changing extremes, on both ends of our thermometers and rain gauges.
A University of Tennessee at Knoxville researcher in 2012 completed a first-of-its-kind study to predict heat waves for the top 20 cities in the eastern United States. His findings put the Tennessee Valley in the cross hairs of climate craziness with a likelihood of more intense heat waves and drastically wetter weather. For this region he predicted as much as 17 inches of extra annual rainfall.
In 2013, that's just what we got: our normal 52.5 inches of rain plus another 16.29 inches, to total nearly 69 inches of rain for the year, according to the National Weather Service.
We had a cooler than normal summer, but remember that the study measured the likelihood of "more intense heat waves," and we had a string of 100-degrees-plus days across the region in June.
That was about the same time that Jeff Masters, meteorology director at the private service Weather Underground, told The Associated Press science and environment reporter Seth Borenstein: "I've been doing meteorology for 30 years and the jet stream the last three years has done stuff I've never seen. ... The fact that the jet stream is unusual could be an indicator of something. I'm not saying we know what it is."
The jet stream is a big river of air high above Earth that dictates much of the weather for the Northern Hemisphere, and it has been unusually erratic the past few years. The Associated Press chronicled the strangeness:
In May, early California wildfires fueled by heat contrasted with more than a foot of snow in Minnesota. Seattle was the hottest spot in the nation one day, and Maine and Edmonton, Canada, were warmer than Miami and Phoenix.
Before that, the winter of 2011-12 seemed to disappear, with little snow and record warmth in March. That was followed by the winter of 2012-13 when nor'easters lined up to strike the same coastal areas repeatedly. Superstorm Sandy took an odd left turn in October and veered straight into New Jersey. We'd also seen one 12-month period with a record number of tornadoes, immediately followed by 12 months that set a record for lack of tornadoes.
Now we're warned of below-zero chills in the heart of Dixie.
Last September, the researchers with the U.S. National Oceanic and Atmospheric Administration and the British meteorological office concluded in a new report that about a half dozen of those wild weather events — including Sandy — occurred because man-made global warming increased the likelihood for them. Another half dozen in the 12 events examined were just the results of the random freakishness of weather.
Their conclusion represented a sea change (no pun intended) to global warming. Scientists used to say that individual weather events — a specific hurricane or flood, for example — cannot be attributed to climate change. But this time, researchers used computer simulations to look at extreme events in a more nuanced way, measuring the influence of climate change on their likelihood and magnitude.
"We've got some new evidence that human influence has changed the risk and has changed it enough that we can detect it," study lead author Peter Stott, head of climate monitoring and attribution for the British meteorological office, told international reporters as he released the study.
It's not the warming, folks. It's the extremes. And, yes, we can do something about it. That "something" starts with not denying science.