Saturday, December 16, 2017

Scientists Pin Extreme 2016 Weather Specifically On Climate Change

This severe 2016 flood in China was one of many extreme
weather events that year made worse by climate change
For many years now, scientists have always told us it's really hard to pin a specific extreme weather event on climate change. Global warming just makes those wacky weather moments more likely.

Now, those scientists are getting better at saying certain weather extremes can be definitively linked to climate change. And they're pointing to some weird weather in 2016 as examples.

A peer-reviewed report called "Explaining Extreme Events in 2016 From A Climate Perspective" that takes a serious look at this very phenomenon. It was published in the Bulletin of the American Meteorological Society.

"For years, scientists have known humans are changing the risk of some extremes. But finding multiple extreme events that weren't even possible without human influence makes clear that we're experiencing new wather, because we've made a new climate," said Jeff Rosenfeld, editor-in-chief of the AMS Bulletin.

The report said 116 scientists from 18 countries looked at nearly two dozen extreme weather events across the globe that happened in 2016.

The planet had its hottest overall year in modern times during 2016, and that was the biggest weather news the scientists studied from that year. In terms of specific weather events, some of those cited in the report you might have heard of. Others were more obscure and esoteric, but would have big effects on people living near where they occured. Or even beyond the local impact.

One intriguing weather event the scientists looked at was extreme heat in Southeast Asia during 2016. There was an El Nino weather pattern in 2015 and early 2016. That pattern does tend to increase heat in Southeast Asia, whether or not global warming is a factor.

The report concluded: "The 2016 extreme warmth across Asia would not have been possible without climate change.... Although El Nino was expected to warm Southeast Asia in 2016, the heat in the region was unusually widespread."

The report continues: "All of the risk of extremely high temperatures over Asia in 2016 can be attributed to anthropogenic (human caused) warming. In addition, the ENSO condition (El Nino) ae te extreme warmth two times likely to occur."

Two of the esoteric events the scientists cited were weird ocean warming in the Bering Sea and the Gulf of Alaska near Alaska, and around the Great Barrier Reef in Australia.

Like the Southeast Asian heat, natural variability played a role in the ocean warmth near Alaska and Australia.  But the natural variability combined with climate change made the warmth unprecented. Why should we care about a warm Bering Sea? For one thing, it caused algae blooms, marine die-offs and contributed to a lack of Arctic ice. That damaged fisheries, and worse, a lack of ice in the Arctic might be messing with weather patterns, affecting, you, me and the rest of us in the Northern Hemisphere.

Of course, not all extreme weather events from 2016 are attributable to climate change. The study noted a big blizzard in the Mid-Atlantic States and a drought in Brazil that year were just random weather events, with little if any input from climate change.

Bob Henson in his Weather Underground Category 6 blog cited another study, which was actually a review of a number of studies that looked into weather particular extreme weather events are attributable to climate change.

Henson wrote that the analysis publishe by the Energy and Climate Intelligence Unit, a non profit grou that focuses on climate change "looked at 59 extreme weather/climate change attribution studies published in the two years since the Paris Climate Accord in 2015. The analysis found that 41 of the studies demonstrated that climate change had made extreme weather events more intense and/or longer lived, and that a few of them had costs and death tolls that could be partially attributed to human-caused climate change."

I'm sure there will be a lot more science coming as researchers peer into more and more individual weather events to see ever more precisely how climate change is affecting us, or more often, screwing us over

No comments:

Post a Comment