Is Superstorm Sandy a harbinger of the 'new normal' because of global warming?

Long before Superstorm Sandy subsided, a new storm arose—an opportunistic attempt to score political points out of a great tragedy, as some people rushed to blame the powerful storm on climate change.

Al Gore said, “We must heed this warning and act quickly to solve the climate crisis.” Former Obama administration green jobs czar Van Jones tweeted that Sandy proved Gore “was right.”

New York Gov. Andrew Cuomo blamed Sandy on global warming, and so did New York City Mayor Michael Bloomberg, who said so in his endorsement of President Barack Obama. Kevin Knobloch, speaking for the Obama campaign, said, “We know this is going to be our future. This is our new normal.”

Yet for all the political rhetoric, there is no scientific basis to claim that global warming caused or strengthened Sandy. Roger Pielke Jr., professor of environmental studies at the University of Colorado and a leading researcher on hurricane history, wrote, “To call Sandy a harbinger of a ‘new normal,’ in which unprecedented weather events cause unprecedented destruction, would be wrong. This historic storm should remind us that planet Earth is a dangerous place, where extreme events are commonplace and disasters are to be expected.”

The scientific journal Nature warned, “Better models are needed before exceptional events can be reliably linked to global warming.” Climatologist John Christy of the University of Alabama told Congress in September that there is no evidence that global warming has caused, or will cause, more frequent or intense severe weather events.

The National Hurricane Center’s Chris Landsea explained in a lecture just days before Sandy struck that even assuming the global warming asserted by the UN Intergovernmental Panel on Climate Change, studies found that by 2100 there will be no more than a 3 percent increase in average hurricane intensity—within the margin of error in estimating wind speed and therefore undetectable.

Landsea cited studies indicating that Atlantic hurricanes, for reasons peculiar to the region, would actually become weaker with global warming. So if global warming had anything at all to do with Sandy, it made her weaker, not stronger.

The studies also found, Landsea said, “a big decrease in the overall frequency” of hurricanes—by about 25 percent—and “fewer major hurricanes.” The result? Less threat with global warming.

“While it’s hardly mentioned in the media, the U.S. is currently in an extended and intense hurricane ‘drought,’” Pielke wrote. “The last Category 3 or stronger storm to make landfall was Wilma in 2005. The more than seven years since then is the longest such span in over a century.”

But if that’s so, why do hurricanes seem to do so much more damage now than before? It’s because they do. But although damage is increasing, frequency and intensity have nothing to do with the change.

The actual cause? More property in harm’s way.

Take Miami Beach, Fla., where there was only one significant building in 1926. Today there are scores of high-rises, thousands of businesses and luxury homes, and hundreds of expensive boats in marinas. The Great Miami Hurricane of 1926 caused about $100 million in property damage. According to Landsea, if one just like it struck Miami today, it would cause about $165 billion in property damage—about 50 percent more than Katrina caused.

When Tropical Cyclone Nargis hit Myanmar in 2008, it caused only about $4 billion in property damage, but it killed about 140,000 people—people vulnerable because they were poor. If Sandy had caused the same property loss rate in the region it hit as Nargis did in Myanmar, it would have destroyed somewhere between $1.1 trillion to $2.2 trillion in property—22 times the $50 billion to $100 billion now estimated. More important, if it had caused the same death rate, it would have killed 288,000—2,600 times as many as the approximately 110 it did kill.

Why the lower rates from Sandy than from Nargis? Wealth made property, and especially people, less vulnerable.

To put it starkly, if there were no property in the path of a hurricane, it would be less likely to destroy wealth but more likely to kill whatever people were there. Paradoxically, this means a rising trend in damage caused by hurricanes is doubly good news—it reflects growing prosperity, which means increased safety for people.