It’s like waving a red flag in front of the bull these days to mention climate change/global warming — some believe it, some don’t, some couldn’t care less, some think it an Al Gore/Obama/pointy-headed liberal fairy tale, some predict in another 50 years cotton will be growing in Minnesota and that New York, Miami, L.A., and most coastal cities will have become underwater oyster farms (to which others snarkily respond, hey, urban renewal compliments of Mother Nature).
Regardless, few will dispute that, for whatever reason —man-caused or just M. N. at work — we’re in a warming trend. June kicked off with record or near-record temps in many areas, including the Mid-South, which was 10 degrees or more above normal.
This on the heels of major flooding in the nation’s midsection, the result of heavy winter/spring rains and melt from an unusually heavy winter snowpack, both of which global warming adherents contend are due to shifting weather patterns caused by increasing temps.
The flooding is now the center of yet another argument: that a hotter Earth is giving rise to increasing incidences of global snow/ice melt in arctic regions, which puts more water vapor into the atmosphere, which is then redistributed in other areas as more snow and rain, boosting chances of flooding.
A study published in the Feb. 17 issue of the journal Nature posits a link between heavier than usual precipitation over North America and global warming. Other weather observers pooh-pooh the idea, saying the massive snowfalls and torrential rains were from a weakening La Niña phase of the El Niño-Southern Oscillation and the Pacific Decadal Oscillation. This, they contend, resulted in an abnormally stronger jet stream across the U.S., which in turn brought more powerful storms, tornadoes, and floods.
As for this year’s flooding on the Mississippi and its tributaries, which has been described as a 100-year event, that number can be somewhat misleading, says John Barry, author of the monumental book, “Rising Tide: The Great Mississippi Flood of 1927 and How It Changed America.”
In an interview on NPR’s “Here and Now,” he noted that while the government said the system of levees built after the great flood were constructed to withstand 100-year floods, “It’s Orwellian terminology — what it means is a flood with a 1 percent chance of occurring in any given year. But over time, the odds change. In the average person’s lifetime, there is a 56 percent chance they will see a flood greater than a 100-year flood. And there’s a 20 percent chance they will see two floods in their lifetime greater than a 100-year flood.
“It is,” Barry said, “by far the worst standard in the developed world. It came about as a political compromise.”
While the Corps of Engineers pushed for levees that could handle a 500-year or greater flood (most European countries build to a 2,000-year flood standard), financial considerations resulted in the lower standard that's in place today.