Storm Warnings

The National Association of Insurance Commissioners, founded in 1871 and headquartered in Kansas City, Missouri, bills itself as the “oldest association of state officials” in the country. Every three months, its members, who include the chief insurance regulators of all fifty states plus the District of Columbia, hold a four-day meeting to discuss issues of common concern. The association’s fall, 2005, meeting was scheduled for this past weekend, and, in addition to seminars on such perennial favorites as “Property Casualty Reinsurance” and “Receivership and Insolvency,” the event’s planners had organized a session on a new topic: global warming. Given recent events in Louisiana and Mississippi, a session on weather-related disasters would surely have been well attended. Unfortunately for the association, the meeting was booked into the Sheraton in downtown New Orleans.

Katrina was so destructive—whole towns and cities devastated, and their traditions swept away—that anyone who would presume to comment on it has a heavy burden. A disaster of this magnitude seems to demand not dispassionate analysis but simple human empathy. To use it as an occasion to point out the folly of U.S. energy policy, as, for example, the German environmental minister, Jürgen Trittin, did, is to invite the charge of insensitivity, or even worse. “The American president shuts his eyes to the economic and human damage that the failure to protect the climate inflicts on his country and the world economy through natural catastrophes like Katrina,” Trittin wrote in the Frankfurter Rundschau. An editor for the London Times online accused Trittin of “intellectual looting,” while the Web version of Der Spiegel announced “another low point for transatlantic relations—and set off by a German minister. How pathetic.” But, callous as it may seem to say so, America’s consumption of fossil fuels and catastrophes like Katrina are indeed connected.

Though hurricanes are, in their details, extremely complicated, basically they all draw their energy from the same source: the warm surface waters of the ocean. This is why they form only in the tropics, and during the season when sea surface temperatures are highest. It follows that if sea surface temperatures increase—as they have been doing—then the amount of energy available to hurricanes will grow. In general, climate scientists predict that climbing CO2 levels will lead to an increase in the intensity of hurricanes, though not in hurricane frequency. (This increase will be superimposed on any natural cycles of hurricane activity.) Meanwhile, as sea levels rise—water expands as it warms—storm surges, like the one that breached the levees in New Orleans, will inevitably become more dangerous. In a paper published in Nature just a few weeks before Katrina struck, a researcher at the Massachusetts Institute of Technology reported that wind-speed measurements made by planes flying through tropical storms showed that the “potential destructiveness” of such storms had “increased markedly” since the nineteen-seventies, right in line with rising sea surface temperatures.

The fact that climbing CO2 levels are expected to produce more storms like Katrina doesn’t mean that Katrina itself was caused by global warming. No single storm, no matter how extreme, can be accounted for in this way; weather events are a function both of factors that can be identified, like the amount of solar radiation reaching the earth and the greenhouse-gas concentrations in the atmosphere, and of factors that are stochastic, or purely random. In response to the many confused claims that were being made about the hurricane, a group of prominent climatologists posted an essay on the Web site RealClimate that asked, “Could New Orleans be the first major U.S. city ravaged by human-caused climate change?” The correct answer, they pointed out, is that this is the wrong question. The science of global warming has nothing to say about any particular hurricane (or drought or heat wave or flood), only about the larger statistical pattern.

For obvious reasons, this larger pattern is also of deep interest to the insurance industry. In June, the Association of British Insurers issued a report forecasting that, owing to climate change, losses from hurricanes in the U.S., typhoons in Japan, and windstorms in Europe were likely to increase by more than sixty per cent in the coming decades. (The report calculated that insured losses from extreme storms—those expected to occur only once every hundred to two hundred and fifty years—could rise to as much as a hundred and fifty billion dollars.) The figures did not take into account the expected increase in the number and wealth of people living in storm-prone areas; correcting for such increases, the losses are likely to be several hundred per cent higher. A report issued last week, which was supposed to have been presented at the National Association of Insurance Commissioners’ meeting in New Orleans, noted that, even before Katrina, catastrophic weather-related losses in the U.S. had been rising “significantly faster than premiums, population, or economic growth.”

Since President Bush announced that the country was withdrawing from the Kyoto Protocol, in March, 2001, the Administration has offered a variety of excuses for why the U.S., which produces nearly a quarter of the world’s greenhouse-gas emissions, can’t be expected to cut back. On the one hand, Administration officials have insisted that the science of global warming is inconclusive; on the other, they’ve cited this same science to argue that the steps demanded by Kyoto are not rigorously enough thought out. As the rest of the world has adopted Kyoto—earlier this year, the treaty became binding on the hundred and forty nations that had ratified it—these arguments have become increasingly indefensible, and the President has fallen back on what one suspects was his real objection all along: complying with the agreement would be expensive. “The Kyoto treaty didn’t suit our needs,” Bush blurted out during a British-television interview a couple of months ago. As Katrina indicates, this argument, too, is empty. It’s not acting to curb greenhouse-gas emissions that’s likely to prove too costly; it’s doing nothing.