Hurricane Maria, currently on a collision course with Puerto Rico, intensified explosively in one day from a Category 1 storm to Category 5 superstorm. The Prime Minister of Dominica said Tuesday that Maria caused “mind boggling” devastation when it tore through his island nation.

“As [we] see storms like Irma and now Maria intensify from tropical disturbances to Category 5 hurricanes in record time, we see hints of yet another potential threat,” climatologist Michael Mann told ThinkProgress via email. “We may have less time to prepare and react to monster storms, hindering our adaptive capacity to deal with their devastating impacts.”

Climate science deniers have sought to dismiss scientists’ discussion of the link between human-caused climate change and more intense hurricanes as “idle chatter.” It is anything but.

Maria is the fourth hurricane to hit a strength of Category 4 or 5 this season, joining Jose, Irma, and Harvey. Remarkably, half of all Atlantic hurricanes this season have been Category 4 or 5.


Or, rather, it would have been remarkable to see such a high proportion of rapidly-intensifying superstorms if that hadn’t been predicted by climate scientists. Hurricanes draw energy from the ocean. The warmer the ocean gets, the greater the proportion of Category 4 and 5 superstorms we will see (see chart below).

Climate models predicted human-caused global warming will boost the proportions in the highest hurricanes (4-5) compared to the lowest (1-2). The ACCI is a measure of human-caused warming. CREDIT: NCAR 2013.

A 2013 study, led by Greg Holland of the National Center for Atmospheric Research (NCAR) found that “since 1975 there has been a substantial and observable regional and global increase in the proportion of Cat 4–5 hurricanes of 25–30 percent per °C of anthropogenic global warming.”

Holland, the Director of NCAR’s Capacity Center for Climate and Weather Extremes, pointed out last week that “globally, the proportion of Cat 4 and 5 hurricanes has increased from ~20 percent of all hurricanes to around 40 percent due to climate change over the past 60 years.”

That rapid growth “has arisen through an increased number of weaker storms moving up into much higher intensities,” he added.

Indeed, climate scientists have pointed out the weaker storms have been strengthening much more rapidly into stronger storms than they ever did before. “Storms are intensifying at a much more rapid pace than they used to 25 years back,” explained the author of a 2012 study. “They are getting stronger more quickly and also [to a] higher category. The intensity as well as the rate of intensity is increasing.”


A 2015 study on the impact of sea-surface temperatures on the intensity of hurricanes in the North Atlantic found “intensification increases by 16 percent for every 1°C increase in mean SST.” And a 2016 study warned that “the vast majority (79 percent) of major storms” are rapid intensification storms,” and “the most intense storms” are those that undergo rapid intensification.

So it’s no surprise that Harvey spun up from a tropical depression to a Category 4 superstorm in two days. Or that Irma saw a “rapid intensification burst,” as meteorologist Jeff Masters described it.

It’s also no surprise that the most prominent climate science deniers would like scientists to stop talking about the link between human-caused climate change and more intense hurricanes.

Two weeks ago, EPA Administrator Scott Pruitt slammed scientists for discussing “the cause and effect of these storms,” saying that “to use time and effort to address it at this point is very, very insensitive to the people in Florida.”

On Friday, Myron Ebell, a climate science denier who ran Trump’s EPA transition working group, wrote a piece in The Hill demanding scientists “stop the loose talk about hurricanes and global warming.” Ebell went so far as to defend the EPA head saying, “Pruitt is of course absolutely right to focus on government action rather than idle chatter.”


For those who have built a career denying the existence and severity of climate change, well-established science is nothing more than “idle chatter.” But for Americans who must live through — and plan for — an ever higher proportion of super hurricanes, the scientific reality of the hurricane-climate connection is gravely serious.

As we’ve written, if we can’t talk about what’s to come, and what’s driving it, then how can we plan for it? How can we rebuild wisely?

It’s long past time for this country to start seriously planning for the warming-driven rise in super-hurricanes like Harvey, Irma, and Maria — and in the sea levels that worsen their storm surge. As Mann said, the summer’s spate of monster hurricanes “is a reminder that there is only one safe solution: stemming the problem at it’s source, and shifting rapidly away from a fossil fuel energy-driven economy.”