Hurricane Florence Is a Warning of What’s to Come
Right now, Hurricane Florence is spinning toward the mid-Atlantic coast like a giant thermo-aquatic buzz saw. Hurricanes are fickle and can shapeshift at the last minute, but Florence is on track to be one of the biggest hurricanes in U.S. history, with winds that are expected to accelerate to 155 mph and a storm surge up to 15 or 20 feet. Already 1.5 million people have been evacuated from the Carolina coast, and surely more evacuation orders are to come. This is a monster storm, and it will likely have a devastating impact on the people who live in the region. And Florence is just one of three big storms that are spinning simultaneously in the Atlantic, at what is historically the peak of hurricane season.
Welcome to life on our superheated planet.
Every hurricane, like every snowflake, is unique, driven by a particular mix of ocean temperature and atmospheric circulation patterns, among other things. On cable networks, you will see a lot of images of bent-over trees and reporters standing in 100-mph-plus winds and houses with their roofs blown off. But like Hurricane Harvey, which caused massive flooding in Houston last year, water is likely to be more deadly and destructive than the wind.
Hurricanes push a lot of water in front of them as they spin along. With Florence, the angle of approach is coming straight in at 90 degrees, which will push a big wall of water in front of it. As Andrew Freedman at Axios points out, the Carolinas are uniquely vulnerable to storm-surge flooding because the continental shelf extends far offshore, by about 50 miles, creating a large shallow area that enables a storm to build up water to great heights. (Other hurricane-prone areas, like southern Florida, have a steeper slope offshore, and typically see lower surge amounts.) A surge of 15 to 20 feet or higher could sweep over barrier islands on the Outer Banks and reshape the coastline.
But inland rainfall is likely to be equally damaging. Right now, meteorologists see the storm hitting the coast, then stalling over land, possibly for as long as four or five days, and dumping huge amounts of rainfall, up to 30 or 40 inches, affecting a much wider area than the center of the hurricane itself.
That means massive inland flooding that can extend hundreds of miles from the center of the storm. This is a hidden and under-reported risk: One in four hurricane deaths is from freshwater flooding. And as meteorologist Marshall Shepard points out, the saturated ground means lots of falling trees. (In Hurricane Sandy, 19 percent of the 106 deaths were from falling trees.)
But Florence is not simply a natural disaster. It is a manufactured catastrophe, a product of choices we have made about how we live, where we live and how we think (or don’t think) about our future.
For one thing, our 150-year fossil-fuel binge, which has superheated the atmosphere, has amped up the energy and intensity of big storms like Florence. No, climate change does not cause hurricanes. But it does make them more dangerous. (For more on the relationship between climate change and hurricanes, see climate scientist Katharine Hayhoe’s excellent video). Florence’s intensity is directly fed by the extra-warm waters of the Atlantic (as high as 86 F), which acts like jet fuel for the storm.
#Florence is getting supercharged by near-record warm (~2C/3.6F above normal) subtropical North Atlantic ocean surface temperatures (https://t.co/8vutoyB14S). Even just a 1C global-warming trend can increase the likelihood of this sort of ‘ocean heat wave’ ten-fold or more…
— Michael E. Mann (@MichaelEMann) September 10, 2018
Another consequence of our warming planet is melting ice sheets in the Arctic and Antarctica, which is raising sea levels. As the work of University of Florida scientist Andrea Dutton and others has shown, the mid-Atlantic is a particular hotspot for sea-level rise. Between 2011 and 2015, due to a number of factors, including natural variability in atmospheric circulation and changes in ocean currents, the southeastern coast of the U.S. saw sea levels rise six times faster than the global average. And of course, the higher the ocean level, the bigger the storm surge.
And how have we reacted? Rather than adapt to rising waters, or move aggressively to cut carbon pollution, in 2012 the North Carolina legislature outlawed taking sea-level rise into account in their coastal management strategy.
But we’ve done a lot to increase the risk from storms like Florence in other ways, too. For example, a recent study shows that navigation-dredging has doubled tidal ranges in Wilmington, North Carolina, and significantly increased surge exposure over the past century. We have also built a lot of homes in places that are high-risk for hurricanes and flooding. Stephen Strader, an associate professor of geology at Villanova University, points out the expanding bullseye of developed land in the region now at risk for flooding.
Exposure change in region forecast to be affected by #Florence. 1,325% increase in the number of homes within the cone of uncertainty. While much of the development has been along the coast, most is inland and subject to flooding. The water that kills, not the wind. #HaveAPlan pic.twitter.com/LBjyII1IJQ
— Stephen M. Strader (@StephenMStrader) September 10, 2018
As Dutton, the University of Florida scientist, put it in an email to me: “No need to mince words here. The outrageous coastal development practices need to change and unfortunately, this storm might just be the one to squeeze the insurance market enough to make that happen. Especially on the heels of Irma, Maria and Harvey, which have already stretched the available resources.”
In the next few days, assuming Florence continues on its current path, what we’re likely to see is a lot of wind, a lot of crashing waves, a lot of suffering, a lot of people losing everything. It will be emotional and dramatic, and climate scientists like Dutton and Hayhoe will try to make the connection between how we live and the storms we create. But then the winds will die down, the waters will recede, and we will move on.
We know what's next. #ClimateChange will be mentioned after these big hurricanes are strengthened by warming seas for almost as long as #GunControl is discussed following mass/school shootings.
— Kris Karnauskas (@OceansClimateCU) September 11, 2018
In the aftermath of Florence, the biggest challenge will not be coming up with the billions for rebuilding, but using it as an opportunity to think differently about the world we live in. The storm may be a natural disaster, but it is also a reflection of the world we have built.
Maybe Florence will change something, maybe there will be a message in a bottle that washes up somewhere on the coast that wakes the world up to the dangers we face on our superheated planet. But I thought the same thing after Hurricane Katrina, and Sandy, and Maria.
Yes, there are things to be optimistic about. Activists are taking to the streets. Electric cars are catching on fast. California Gov. Jerry Brown just signed a bill mandating that the state’s utilities move to 100-percent zero-emission electricity generation by 2045, as well as an executive order requiring the state to become carbon neutral by that same year.
But as U.N. Secretary General Antonio Guterres put it the other day, “Climate change is moving faster than we are.” President Trump — who believes climate change is a hoax perpetuated by the Chinese — is doing everything he can to kill any action that would slow it down. On the eve of the storm, the New York Times reports that the EPA is about to roll back restrictions on methane emissions, a potent greenhouse gas. In July, the EPA proposed weakening a rule on carbon dioxide pollution from vehicle tailpipes. And in August, the agency proposed replacing a regulation on coal-fired power plants with a weaker one that will allow far more global-warming emissions to flow unchecked from the nation’s smokestacks.
The stupidity of this is breathtaking — the political equivalent of a suicide pact for human civilization as we know it today. That’s the message written in the wind and water of Hurricane Florence, and in the economic damage and human suffering it will bring. This time, I hope we listen.
This story has been updated to correct the spelling of Katharine Hayhoe’s name.