Lauren Rosenthal and Brian K Sullivan | (TNS) Bloomberg News
Severe rains bucketed down on central Europe, Africa, Shanghai and the U.S. Carolinas this week, underscoring the extreme ways in which climate change is altering the weather.
Different meteorological phenomena are behind the series of storms, according to climate scientists, though they agree an underlying factor for the supercharged rainfall is global warming writ large. Research has shown that hotter air is capable of carrying more moisture and is more likely to cause intense precipitation.
And it’s not just the amount of rain that falls, but where it lands. Emergency preparation, infrastructure and access to relief funds have led to vastly different outcomes — a reminder that the effects of climate change are not being felt equally across a warming world. At least 1,000 people have died in Africa, and millions of people have been displaced. In Europe, meanwhile, the toll is considerably lower, and government officials have already pledged vast sums of public funding to rebuilding.
“There are these fingerprints of climate change in these heavy rainfalls leading to these big floods,” said Hannah Cloke, a professor of hydrology at the University of Reading. “But we have to recognize that people have changed the landscape, made it more likely that people are in the way of these floods too.”
Storm Boris, a slow-moving system, began unleashing torrential rain across Poland, Czech Republic, Romania, Slovakia, Austria, Hungary and Germany last week. St. Poelten, the capital of Lower Austria, saw 409 millimeters (16 inches) of rain over five days, almost double the previous five-day record. More than 20 people have died.
As the rains taper off in some areas, towns and villages are preparing for floodwaters to peak over the coming days due to river swelling. Several countries had already invested in control systems and retention reservoirs that are helping to curb some of the damage.
The region’s heavy rains can be traced back to the jet stream, a narrow and fast-moving ribbon of winds in the Earth’s upper atmosphere that travels from west to east. The jet stream is more orderly in the winter months, when cold air prevents its winds from wandering off track. In the summer and early fall, however, the system has a tendency to meander and “buckle,” sometimes becoming stuck on masses or warm air.
Current radar and satellite imaging show the “jet stream is clearly buckled in large, sharp meanders, causing stagnant weather systems around the Northern Hemisphere,” said Jennifer Francis, a senior scientist at the Woodwell Climate Research Center based in Massachusetts. It’s not clear exactly what’s caused the jet stream to warp this season, she said, but “raging ocean heat waves” due to global warming were one culprit. Average sea surface temperatures were 0.96C (1.73F) above normal in August, the second-hottest month on record.
Scientists also concluded that human-caused climate change worsened severe rains across Germany and Belgium that caused catastrophic flooding in 2021. A cut-off low, which broke away from the jet stream, dragged moisture from the Mediterranean and slowly wrung it out across central Europe. That resulted in Germany’s costliest disaster on record, racking up a bill of $40 billion. This time, Europe was better prepared, with forecasters predicting historic rains …read more
Source:: The Mercury News – Entertainment
