Wednesday, February 13, 2019

    IF YOU WANT TO GO BACK TO THE FUTURE, IT'S ABOUT
                            THREE HOURS SOUTH OF HERE


Science writer Sid Perkins has raised the profile of a recent Nature Communications  piece,
Contemporary climatic analogs for 540 North American urban areas in the late 21st century
by Matthew C. Fitzpatrick & Robert R. Dunn , noting that 
Using 27 different climate models, researchers looked at 12 different aspects of climate—including maximum and minimum temperatures, precipitation, and how those factors vary with the seasons—for each location under two scenarios: one in which atmospheric concentrations of carbon dioxide (CO2) rise from 410 parts per million (ppm) today to about 650 ppm in the year 2100, and another in which CO2 levels rise to about 1370 ppm. Then, they compared projected data points from each city to the climates those locales experience now. 
In the lower-emissions scenario, about 70% of the cities have a “future climate sister city,” but it’s typically hundreds of kilometers away and farther south, the researchers report today in Nature Communications. For example, residents of Washington, D.C., can expect a climate in the 2080s that resembles the current climate in Paragould, Arkansas, about 132 kilometers northwest of Memphis, Tennessee. Meanwhile, folks in Anchorage, Alaska, may experience the same climate as today’s Owen Sound, Canada, about 160 kilometers northwest of Toronto.
Looking  at the maps on page 17 of the 2004 US census document 

Over the course of the 20th century, the mean center of population continually moved westward, starting from Bartholomew County, Indiana, in 1900, progress- ing through Indiana, crossing Illinois, and by 2000 stopping in Phelps County, Missouri (see Figure 1-5). This represents a shift of 324 miles west and 101 miles south from its location at the start of the century.


Which is to say that the mean and median centers of US population have already shifted hundreds of kilometers southwest in a manner eeirily paralleling the vectors of climate change that Fitzpatrick & Dunn plot from  IPCC RCP 4.5



It may vex climate communicators that the electorate has been tramping off in the general direction of the Apocalypse for the last hundred years, but the great warmward migration offers a Future of Climate meme that rivals model intercomparison pixel matching:

Having shifted themselves 101 miles south and 324 miles west in the 20th Century, the American people could respond to 21st Century climate change by heading back where they came from.

So modelers beware. The Climate Wars could come to an anticlimactic end if the electorate concludes that we have seen the future, and it's about a three hour drive south of here.