NOAA report: Global warming contributed to dozens of extreme weather events in 2015

A National Oceanic and Atmospheric Administration report published in the Bulletin of the American Meteorological Society on Thursday found that 80 percent of extreme weather events in 2015, including heat waves, floods and droughts, were influenced by climate change.

In the NOAA’s fifth annual research collaboration entitled, “Explaining Extreme Events from a Climate Perspective”, 116 climate scientists examined 30 unusual weather cases and found 24 were made more intense or likely due to significantly higher global temperatures.

Of the 24 attributable events, 10 were related to heat waves or shorter periods of extremely high temperatures, and also included a new record that was set for average overall global temperature in 2015.

Other weather phenomenon effected by global warming include tropical cyclones in the western Pacific Ocean, Alaskan wildfires, rainless or “sunny day” flooding in Miami in September 2015, record winter sunshine in the UK, “extreme drought” in western Canada, “snowpack drought” in Washington state and record low sea ice in the Arctic Ocean.

Specifically, researchers found that the flooding in Miami caused by high ocean tides was 500 percent more likely to occur in 2015 compared to two decades ago, and heat waves in Pakistan and India were 800 times more probable.

Weather events found not to have a connection with climate change include a southern moving polar vortex that brought below average temperatures to the eastern U.S., a late-arriving rain season in Nigeria and consecutive days of heavy rain in Chennai, India.

Separate studies, however, have found a causal relationship between melting Arctic sea ice and the southerly flow of the polar air mass that enveloped much of eastern North America in February 2015.

“There’s lots of reasons why a paper may not find a role for climate change,” said the study’s lead editor, Stephanie Herring, who pointed to new trends not yet associated with warming and potentially insufficient methods of detection.

“After five years of the BAMS’ ‘Explaining Extreme Events’ report, we’re seeing mounting evidence that climate change is making heat waves more extreme in many regions around the world,” she continued.

Since the first NOAA-sponsored study was issued in 2012, approximately 70 out of slightly over 100 potentially life-threatening weather occasions have been found to be effected by global warming.

“As we get better at distinguishing the influence of climate change from natural variability, the local significance and impacts of this global phenomenon are becoming clearer,” Herring concluded.

 

[AP] [Climate Central] [NOAA.gov] [Photo courtesy Carbon Brief]