Kerry Emanuel on climate change and hurricanes

“‘[With global warming, we could see] a 50-percent increase in the destructive potential” of the most powerful tropical storms,’ says meteorologist Kerry Emanuel of the Massachusetts Institute of Technology.”

For decades, MIT’s Kerry Emanuel has been a go-to researcher for those seeking insight into how climate change may affect catastrophic storms. The above quote is from 1992, in a Newsweek article “Was Andrew a Freak — Or a Preview of Things to Come?” — and has never been more timely.

Kerry is also an eloquent and forceful voice pushing leaders around the world to take the risks of climate change more seriously.



Now we’re once again deep into storm season around the world, and it’s not pretty. With events still unfolding in Texas with Hurricane/Tropical Storm Harvey, and weeks of escalating devastating monsoon floods in Bangladesh, India and Nepal, many people are asking: are these extreme storms the result of climate change?

The current thinking: it’s complicated. Foremost, we shouldn’t be seeking a direct causal link between climate change and any particular storm. As Professor Emanuel told The Washington Post’s Chris Mooney a few days ago:

“My feeling is, when there’s a hurricane, there’s an occasion to talk about the subject,” he said. “But attributing a particular [weather] event to anything, whether it’s climate change or anything else, is a badly posed question, really.”

Scientists are clear that climate change has “threat multiplier” effects on storms, increasing the likelihood and severity of some aspects. For instance: warmer waters and warmer air increase the moisture available and the energy in storms; disruptions in atmospheric circulation increase the likelihood of a storm “stalling out” over a region; and ocean storm surges are made more destructive when melting ice caps have raised the baseline sea level.

“The thing that keeps forecasters up at night is the prospect that a storm will rapidly gain strength just before it hits land,” Emanuel recently told Agence France-Presse, citing Harvey as an example. “Global warming can accentuate that sudden acceleration in intensity.”

Interestingly, it’s still uncertain whether global warming will lead to more or less frequent hurricanes. But in terms of catastrophic damage, storm frequency seems less important than the severity of storms, where climate change does have a clear footprint.

Kerry Emanuel has been a frequent contributor on MIT OpenCourseWare. Check out these two courses particularly connected to the storms + climate change issue.

  • 12.103 Science and Policy of Natural Hazards introduces the science of natural catastrophes such as earthquakes and hurricanes and explores the relationships between the science of and policy toward such hazards. It presents the causes and effects of these phenomena, discusses their predictability, and examines how this knowledge influences policy making.
  • 12.340 Global Warming Science provides a scientifically rigorous foundation to understand anthropogenic (human-caused) climate change, an introduction to climate models, the material impacts of climate change, and the science behind mitigation and adaptation proposals. [See also the archived MITx on edX version of this course.]

[Republished from the MIT OpenCourseWare "Open Matters" blog. Image: A satellite measurement of Hurricane Harvey on Aug. 25 found that intense storms in the eastern side were dropping rain at a rate greater than 3.2 inches (82 mm) per hour. Credits NASA/JAXA, Hal Pierce.]



Curt Newton's picture

Here's a bit more from Kerry

Here's a bit more from Kerry Emanuel on Hurricane Harvey, via

SKCN1B92V0?ct=t%28Weekly_Climate_Review8_16_2016%29">Reuters a couple days ago:

“There is universal agreement” that global warming will boost rainfall during hurricanes because warmer air holds more moisture, increasing the risk of severe floods, said Kerry Emanuel, atmospheric science professor at the Massachusetts Institute of Technology.

“If you look at long-term effects of hurricanes on society, the impacts are more about water than wind,” he said. “Harvey is an example of how vulnerable modern society is to rainstorms as the climate warms. It’s solid physics,” he said.

[Re: the article's title, "EPA says climate scientists trying to 'politicize' Texas storm" ??? I for one am glad that scientists like Kerry are doing their job. Which is way more than can be said about the current EPA leadership.]

Rick Shankman's picture

Yes, Curt... I know that.

Yes, Curt... I know that.

Too bad Dr. Emanuel doesn't believe in divestment either, as he wasn't a signatory to the Open Letter to President Rief signed by FFMIT, a whole bunch of other student groups, associations, clubs, committees, and numerous faculty.

He did, however, sit on the MIT Climate Change Conversation Committee.

As you know, there was no divestment.  More talk, but no divestment.

... and, sustainability for MIT now means conversion from burning bunker fuel to methane.  Fossil to Fossil.

Curt Newton's picture

Update: Carbon Brief has just

Update: Carbon Brief has just published a more detailed and thorough consideration of the link between clima

te change and severe storms like Hurricane Harvey.  It includes a link to this short video with Kerry (which I think comes from the Yale Climate Communications crew):



What should we do about it? Eric Holthaus is appropriately blunt in his Politico piece:

“There’s an uncomfortable point that, so far, everyone is skating around: We knew this would happen, decades ago. We knew this would happen, and we didn’t care. Now is the time to say it as loudly as possible: Harvey is what climate change looks like. More specifically, Harvey is what climate change looks like in a world that has decided, over and over, that it doesn’t want to take climate change seriously.”