2017-09-07. Is climate change wreaking weather havoc? Evolving science seeks answers.

posted Sep 10, 2017, 9:48 PM by Alan Gould
By Kurtis Alexander, San Francisco Chronicle. For GSS Climate Change chapter 8. Excerpt: ...There’s still no simple answer to the question, “Was that hurricane caused by climate change?” But scientists can now often say whether an event was more likely, and more severe, due to the warming planet. A team of experts at Lawrence Berkeley National Laboratory, among the pioneers of the evolving science of extreme event attribution, estimated that human-caused climate change probably raised temperatures in California by as much as 4 degrees last week. Similar accounting has been done for the California drought and strings of wildfires across the West, as well as the catastrophic hurricanes Harvey and Irma, whose devastation continues to unfold. ...While scientists can’t blame climate change for causing any one weather system, studies have found that past heat waves in both the U.S. and abroad were so unlikely in the absence of global warming that there was little other explanation for what drove them. Eventually, the research could find that climate change is the primary engine behind some disasters. ...“Around 2000 or so, you mostly would have heard from the scientific community that we can’t draw any connection between global warming and any extreme event,” Diffenbaugh said. “What has happened since, particularly in the past five years, is an explosion of research by multiple groups that are working very hard to pose and test hypotheses of how global warming is possibly influencing individual events.”... http://www.sfgate.com/bayarea/article/Did-climate-change-cause-the-heat-wave-The-12181543.php