2010 was a pretty serious year for Atlantic hurricanes. The season tied with 1995 and 1887 for the third largest number of named storm, with 19, and tied with 1969 for the second largest number of hurricanes, with 12. One of those hurricanes—Earl—reached Category 4 status, with winds hitting a maximum of 145 mph, stronger than anything we’ve yet seen from Hurricane Irene. Danielle, another 2010 hurricane, also hit Category 4, albeit with weaker winds, and Hurricane Alex caused over $18 billion worth of damage in Mexico. Yet for the U.S., the 2010 hurricane season was remembered as a snooze. Not one storm made landfall on the continental U.S.—indeed, Irene will likely be our first since 2008—and even the powerful Earl eventually veered off into the Atlantic, causing little damage.
2010 should be a reminder that it’s not just the strength or frequency of storms alone that matter—it’s where they hit. That’s especially important for Hurricane Irene, which has 65 million people in its sights—more than 20% of the U.S. population—as it bears down the East Coast. Irene is a pretty big storm—Category 2 right now, with winds and rain that extend unusually far from its eye. But the reason Irene is, in the words of President Obama, a “historic hurricane,” isn’t so much because of its strength, but because of where it’s hitting—and what. There’s a lot of wealth and a lot of people in the path of the storm, and the damage will be costly.
How expensive? The Kinetic Analysis Corp. estimates that Irene may cause $13.9 billion worth of damage, and $20 billion of overall economic losses from shipping and work disruptions. Over at the New York Times, Nate Silver crunches some very scary numbers and estimates that a direct hit on New York City—which produces an annual gross domestic product of $1.4 trillion, one-tenth of the nation’s GDP—could cause tens of billions of dollars worth of damage, if not far more:
Apart from the potential loss of life in the most densely populated part of the country, history suggests that the economic damage could run into the tens of billions of dollars, depending on the severity of the storm and how close it comes to the city. Unlikely but theoretically plausible scenarios could have the damage entering the realm of the costliest natural disasters of all time, and perhaps being large enough to have a materially negative effect on the nation’s gross domestic product.
On his blog Roger Pielke Jr.—an expert in natural disasters at
Colorado State University the University of Colorado—does some estimates himself, and predicts that the “effects will be widespread and the damage total considerable.” Real disaster math nerds can check out the ICAT Damage Estimator that Pielke Jr. helped put together, and run the numbers themselves.
Even in the best-case scenario, Irene will almost certainly be the 10th billion-dollar natural disaster the U.S. has suffered so far this year alone, with four months still to go. What gives? Is something making mega-disasters more mega?
Over at the Daily Beast, Bill McKibben has an idea: climate change. McKibben argues that global warming has helped make ocean temperatures warmer, lending storms like Irene more power and more precipitation—making them more dangerous. And he thinks this storm is just the beginning:
Remember—this year has already seen more billion-dollar weather-related disasters than any year in U.S. history. Last year was the warmest ever recorded on planet Earth. Arctic sea ice is near all-time record lows. Record floods from Pakistan to Queensland to the Mississippi basin; record drought from the steppes of Russia to the plains of Texas. Just about the only trauma we haven’t had are hurricanes plowing into the U.S., but that’s just luck—last year was a big storm year, but they all veered out to sea. This year we’re already on letter I—which in a normal year we don’t get to until well into October. Every kind of natural system is amped up, holding more power—about ¾ of a watt extra energy per square meter of the Earth’s surface, thanks to the carbon we’ve poured into the atmosphere. This is what climate change looks like in its early stages.
The science behind warming and storms is a lot more complex than McKibben describes, and it’s worth noting that the average number of hurricanes making landfall on the U.S. has remained at around 1.69 since 1851, without much of a trend upwards or downwards. While it’s obviously true that whether or not a storm makes landfall on the U.S. in a given year is a matter of luck, you’d imagine that if climate change led to more frequent storms, the very real warming we’ve seen over the past century would eventually increase the average number of hurricanes hitting the country. That hasn’t happened yet.
Nor have we seen a clear upward trend in the amount of damage hurricanes have been causing. It’s true that damages from hurricanes has generally increased over the past century, even adjusting for inflation—and you can be sure that Irene will push that trend even higher. But that trend collapses once you normalize for the astounding population and economic growth the U.S.—and especially the East Coast—has experienced over the last 100 years, as this 2008 paper from Pielke Jr. et. al shows. Adjusted for those factors, and even Katrina pales against the great Miami storm of 1926, which would have cost $157 billion in 2005 dollars.
Does that mean we don’t need to worry the impact that climate change might have on major storms? Absolutely not. We suspect that as the ocean surface temperatures warm—as McKibben points out—there will be more fuel for tropical storms, while warming alone will increase the amount of precipitation in the atmosphere. (Warmer air can hold more moisture.) As John Carey wrote earlier this summer in Scientific American, climate change is increasing the odds for certain kinds of extreme weather:
Scientists compare the normal variation in weather with rolls of the dice. Adding greenhouse gases to the atmosphere loads the dice, increasing odds of such extreme weather events. It’s not just that the weather dice are altered, however. As Steve Sherwood, co-director of the Climate Change Research Center at the University of New South Wales in Australia, puts it, “it is more like painting an extra spot on each face of one of the dice, so that it goes from 2 to 7 instead of 1 to 6. This increases the odds of rolling 11 or 12, but also makes it possible to roll 13.”
But trying to isolate the effect of climate change from what we might think of as normal weather—after all, hurricanes have been hitting the U.S. since long before we started burning carbon—is still very difficult. There’s a lot of noise out there. But what’s much more certain is that extreme weather events will become more and more costly because there are more of us in danger zones like coastal areas, and we’re increasingly richer—which means we have more to lose, at least economically. (The bright side is that wealth tends to reduce the loss of life during natural disasters, thanks to better constructed buildings and greater emergency response capacity.) We’ve entered an era in which billion-dollar-plus disasters—whether they’re caused by storms, droughts, quakes or even infectious disease—will become almost commonplace, especially if we fail to adapt.
So let’s make sure we do so. Adaptation can take the form of better emergency response planning and implementation—including on a personal level—and tougher building codes. We should also think seriously about the wisdom of building close to a rising sea—New York City has been smart about trying to prepare for storm surges on some facilities, like sewage treatment plants, but I’ve seen little evidence that anyone wants to limit popular coastal development. In fact, we keep piling up more and more wealth along our coasts, home to some of the most expensive property on the planet. At some point—as the world keeps warming and the risks keep growing—we might want to question the wisdom of concentrating so much financial and human capital in vulnerable places. And not just because of extreme weather—just imagine the global economic damage a major terrorist attack on New York’s financial district would do, or for that the inevitable major earthquake in Tokyo, which would likely cost over $1 trillion.
The smart investors diversifies, spreading their risk out as much as possible. As Irene bears down on the East Coast, maybe we should think about doing the same thing with our property—and our lives.