Research published in Nature Climate Change states that the extreme weather patterns various regions of the world have experienced over the last few years are a result of human influence on the environment, and will worsen by huge degrees if greenhouse gas emissions are not controlled.Quartz reports:
Extreme weather events such as droughts, heat waves, and torrential rainfalls are the most powerful and obvious reminders that the climate is changing. These disasters were happening long before humans started pumping heat-trapping greenhouse gases into the atmosphere, but global warming has tipped the odds in their favor. A devastating heat wave like the one that killed 35,000 people in Europe in 2003, for example, is now more than 10 times more likely than it used to be.
But that’s just a single event in a single place, which doesn’t say much about the world as a whole. A new analysis in Nature Climate Change, however, takes a much broader view. About 18% of heavy precipitation events worldwide and 75% of hot temperature extremes—defined as events that come only once in every thousand days, on average—can already be attributed to human activity, says the study. And as the world continues to warm, the frequency of those events is expected to double by 2100.
“People can argue that we had these kinds of extremes well before human influence on the climate — we had them centuries ago,” said Erich M. Fischer, lead author of a study published Monday by the journal Nature Climate Change. “And that’s correct. But the odds have changed, and we get more of them.”
The study by Dr. Fischer and his colleague Reto Knutti, of the Swiss Federal Institute of Technology in Zurich, is not the first to attribute large-scale changes in extreme weather to human influence on the climate. But it is among the first to forecast, on a global scale, how those extremes might change with continued global warming.
The question is important because while a gradual increase in average temperatures can have profound ecological consequences, it is weather extremes that have the greatest effect on human society. A 1995 heat wave in Chicago killed hundreds of people, and a 2003 heat wave in Europe killed an estimated 70,000.
Scientists believe both were made more likely by the human emissions that are warming the planet, and heat on that scale will become commonplace if emissions are allowed to continue unabated. For now, though, such heat extremes — Chicago temperatures were near or above 100 degrees for four days running that July — are still rare, which makes them difficult to study in a statistical sense.
Source: Blouin News
