Science says: Record heat, fires aggravated by climate change

Heat waves once again set temperature records around the world. Europe has experienced its deadliest fire in more than a century, and one of the 90 great fires of the US West has burned dozens of homes and forced evacuation from at least 37,000 people near Redding, California. Precipitation has caused flooding in the eastern United States this week

It's all part of the summer – but all this is compounded by man-made climate change, say scientists

. Jennifer Francis.

Japan reached 106 degrees on Monday, its hottest temperature ever. Records have fallen in parts of Massachusetts, Maine, Wyoming, Colorado, Oregon, New Mexico and Texas. And then there is madness in Europe, where normally Norway, Sweden and Finland have all seen temperatures never before seen, exceeding 90 degrees. So far this month, at least 118 of these heat records have been established or linked around the world, according to the National Oceanic and Atmospheric Administration.

The explanations should sound as familiar as crushing broken records. 19659002] "We now have very strong evidence that global warming has already put an inch on the scale, increasing the likelihood of extremes such as intense heat and heavy rainfall," said Noah Diffenbaugh, climate scientist of Stanford University. "We are finding that global warming has increased the chances of recording hot events on more than 80% of the planet, and has increased the chances of record wet events by nearly half of the planet."

Climate change is making the world warmer because of the build-up of heat-trapping gas from the burning of fossil fuels such as coal and oil and other human activities. And experts say the jet stream – which dictates the weather in the northern hemisphere – behaves strangely again.

"An unusually twisted jet stream has been in place for weeks," said Jeff Masters, director of Weather Underground. He says that this allows the heat to stay in place in three areas where the folds are: Europe, Japan and the western United States.

The same jet stream caused the 2003 European heat wave, the 2010 Russian wave and the fires. the drought of Texas and Oklahoma in 2011 and the 2016 Canadian wildfires, Michael Mann, climate specialist from the University of Pennsylvania State, pointed out the previous studies conducted by him and others. He said in an email that these extremes were becoming more common because of climate change caused by humans and in particular, the increased warming in the Arctic.

Climatologists have long said that they can not directly connect unique weather events, such as a heat wave, to humans caused climate change without extensive study. In the last decade, they have used observations, statistics and computer simulations to calculate whether global warming increases the likelihood of events.

A study of European scientists revealed Friday that the current European heat wave is twice as likely. global warming, although these conclusions have not yet been confirmed by outside scientists. The World Meteorological Attribution team said it compared thermal measurements and forecasts for the Netherlands, Denmark and Ireland with historical data going back to the early 1900s.

"The world is warming up and heat waves are becoming more and more common," said Friederike Otto, a member of the team and deputy director of the Environmental Change Institute of the University of New York. ; Oxford.

Erich Fischer, extreme weather expert at the Swiss Federal Institute of Technology in Zurich. Part of the analysis indicates that the authors used well-established methods to draw their conclusions.

Kim Cobb, Georgia Tech's climate scientist, said the link between climate change and fires is not as important as with heat waves.

A devastating fire in Greece – with at least 83 dead – is the deadliest in Europe since 1900, according to the International Disaster Database run by the Disease Epidemiology Research Center. In Brussels, Belgium

In the United States on Friday, there were 89 large active fires, consuming nearly 900,000 acres, according to the National Interagency Fire Center. So far this year, fires have burned 4.15 million acres, nearly 14% higher than the average over the past 10 years.

The first major scientific study linking greenhouse gases to stronger and longer heat waves. Entitled "More intense, more frequent and more durable heat waves in the 21st century." The study's author, Gerald Meehl of the National Center for Atmospheric Research, said Friday that "now it reads as a prediction of what is happening and will continue to occur as long as average temperatures continue to rise." It's not a mystery. "

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Borenstein reports from Washington, Jordans from Berlin

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Follow Seth Borenstein on Twitter: @borenbears His work can be found here.

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