Thanksgiving, Climate Change & Hurricanes

Nov 26, 2019

What do turkeys and hurricanes have in common?   Thanksgiving -   the holiday weekend  marks the end of the 2019 hurricane season. This year powerful slow moving storms like Dorian invigorated the conversation about the impact of climate change on hurricanes.  BPR’s Helen Chickering talked with a climate scientist based here in Asheville who has been tackling that question.

“Part of what was so remarkable about hurricane Harvey

At a recent presentation on hurricanes and climate change at the Collider in Asheville, climate scientist Carl Schreck PhD, paused to make a point.     

“Before I go further, I want to make very clear that the climate is warming and humans are causing it,  97% of scientists, my colleagues, agree on those two simple facts.”

Not as clear, Schreck told the crowd, is the impact of climate change on hurricanes.  Schreck is with the North Carolina Institute for Climate Studies, a NOAA partner, based in the Federal building in downtown Asheville where he spends a lot of time investigating tropical weather and its impacts around the globe.

“That’s certainly one of the biggest challenges when we talk about hurricanes and climate change that we know certain aspects of climate change is making hurricanes worse, but hurricanes have always been happening.”

In 2019, Dorian and  Lorenzo were among the the standouts - both category 5 storms.   The fourth consecutive year in which a category 5 developed in the Atlantic.

That’s sound of Dorian hitting the Bahamas, posted by the global news network on You Tube,  which highlights one of the biggest challenge  for scientists as they work to  tease out the climate change impact; record keeping.  Carl Schreck says there isn’t as much historical hurricane data, compared to other extreme weather events like droughts, floods and heat waves. 

“If you go back say 100 years, we would only know about the storms if they made landfall or if some poor ship captain, managed to get close enough to a storm to know about it and survived to tell someone else that it happened.  So we know we’re observing more storms we ever could ever before.” 

That increase in observation - thanks to satellite and other technology is revealing some trends.   Hurricanes pull their power from the ocean, and today’s warmer waters act as a booster.    The warmer atmosphere also plays a role, says Schreck, is  making storms wetter.

”So two things we know most clearly with Hurricanes, essentially they’re  getting wetter, as climate is changing more water vapor in the atmosphere.  So pretty much any heavy rain event is stronger in a warm climate than it would have been in the past, and hurricanes are more efficient at that. “

Sea level rise is another factor says Schreck, making for higher storm surges that can cover more land. And notable for the 2019 season was the snail like pace of several storms as they made landfall,  

A very very slow moving storm, officials the Hurricane center is saying that Dorian is stationary.”

“That is really is at the cutting edge of our science right now.  There was a  study by NOAA’s  Jim Kossin, who’s with the NOAA Center for Environmental Information here, just last year, that was showing  on average forward motions of these storms is slowing down year by year.  But it is just one study so far, we haven’t had a chance to understand why necessarily, so it’s something we’re looking to learn more about.”

And while the 2019 Atlantic Hurricane season is wrapping up, the storm watch continues for Carl Schreck.  Over in the Pacific – Cyclone and Typhoon season are in full swing.  

I’m Helen Chickering, BPR News