Did Climate Change Contribute to Sandy?

As Hurricane Sandy battered the East Coast last week, meteorologists and climate scientists were repeatedly asked to explain what role climate change played in amplifying the storm.

We did our best to answer: We know that a warming climate puts more energy into storms, including hurricanes, loading them with more rainfall and the stronger winds pushing more of a storm surge. That makes flooding more likely. We also know that storm surge now rides higher on sea levels that have risen over the last century due to global warming, amplifying losses where the surge strikes. On the stretch of the Atlantic Coast that spans from Norfolk to Boston, sea levels have been rising four times faster than the global average.

Overall, we know that climate change has stacked the deck so that this kind of event happens more frequently. That answer, however, prompts a deeper, more unsettling question that many want to know: is climate change worsening some recent extreme weather events like super storm Sandy?

The short answer is yes. Climate scientists broadly agree that the extreme weather we’ve seen over the past few years is exactly what we’d expect to see in a changing climate. And it’s not just Sandy; we’re on track to have the hottest year in more than a century of record-keeping in the continental United States, the country has suffered one of the most crippling droughts in history, as well as one of the worst wildfire years in history. Last year, when Hurricane Irene hit the United States, meteorologists called it “unprecedented,” yet Sandy has already outpaced the damage from Irene.

We’ll probably never know the exact point when the weather stopped being entirely natural. But we should consider Sandy—and other recent extreme weather events – an early taste of a climate-changed world, and a grim preview of the even worse to come, particularly if we continue to pump more carbon pollution from smokestacks and tailpipes up into the atmosphere.

 Last weekend, millions of Americans prepared for the storm by turning to meteorologists to tell them where the storm would hit. The meteorologists relied on detailed computer models to form an accurate prediction of where it would hit and how strong it would be.

We climate scientists use models too, and our results are remarkably consistent and remarkably dire. For example, our models predicted an increase in extreme precipitation with global warming, and that’s exactly what we have witnessed. In the northeast U.S. extreme precipitation has gone up 67 percent in recent years, due to the same rain-loading action that pumped up both Sandy and Hurricane Irene. Our models also predicted more heat waves, and again that’s exactly what we have gotten as the most extreme summers are now much more frequent around the world, setting the stage for intense heat waves.

This new world is expensive – damage from Sandy will be in the billions of dollars, with estimates as high as $50 billion. In 2011, the United States broke a record for the most billion dollar weather disasters in one year, fourteen, totaling $47 billion dollars.

It’s time to stop asking when climate change will arrive. It’s here, and we need to move aggressively to curb carbon emissions while also preparing for a changed world. We are at nothing less than a critical juncture.

In addition to more extreme weather, failing to change our ways will mean extreme costs. Not acting on climate change could cost our nation more than 1 percent of GDP by 2025, or $218 billion a year, according to an analysis by Frank Ackerman, an economist at Tufts University. And it skyrockets from there, possibly to an estimated $1.8 trillion by 2100.

Fortunately, scientists have outlined what is needed to meet this challenge. We need to cut industrial carbon pollution. There are several ways to achieve that goal, many of them also money-savers, and as scientists we stand ready to help policymakers figure out the best, most cost-effective ways to do so.

Dr. Bob Corell is a senior policy fellow for the American Meteorological Society and former Chair of the United States Global Change Research Program.

Dr. Jeff Masters is the founder and Director of Meteorology for Weather Underground and a former NOAA Hurricane Hunter.

Dr. Kevin Trenberth is a Distinguished Senior Scientist in the Climate Analysis Section at the National Center for Atmospheric Research.

This article was published at Politico and is copyright 2012 by Politico LLC. We understand that they have given permission to repost. All other rights are reserved by Politico LLC.


  1. No matter to what degree Hurricane Sandy was / was not a result of climate change, there's another obvious lesson I think we can take away --- and that we might be missing so far:

    * Shoreline development is risky.
    * Ignoring evacuation orders can be deadly.
    * Simply rebuilding is not always the best idea.

    If we can't get this basic stuff right, what hope do we have as water levels slowly rise over the next century while our "climate dice" become increasingly loaded?

  2. Now there's a sticky issue.

    "Simply rebuilding" is tied to our concept of land as property.

    People from outside our area may not vividly recall the great conflagration just over a year ago on labor day near Bastrop Texas. People around here remember it. For many in Texas it was the moment of peak horror in a horrible summer.

    People are rebuilding big houses in the former Lost Pines forest, now ironically lost, near Bastrop Texas.

    What choice do they have? They are underinsured and this is the land they have. They get the replacement value of the house if they are well-enough insured, but this was high-priced land by Texas standards, the westernmost expanse of the southern "piney woods", and in commute distance to Austin, which had appeal for many. And people had large lots because that's part olf the Texas exurban thing.

    This is a vast, depressing, burnt-out wasteland, understand.

    They sure as hell aren't going to sell that plot anytime soon. So they build right there.

    Now in this case, at least we know that the Lost Pines will not be lost yet again, at least not soon. (Ignoring climate change, the park rangers are earnestly hoping that the forest comes back. But this was an unnaturally hot fire and some plots may take a long time to seed.)

    I suggest that insurance should have a concept of the land being totalled as well as the house being totalled. The insurance companies would now own the wasteland, rather than unfortunate insured individuals. Or, it could be socially insured and revert to the commons in such an event.

  3. Ultimately, paying people off like that for the amount of damage we're likely already committed to may be impossible. One mechanism for that will be that insurance becomes less and less obtainable. Expandng the National Flood Insurance Program to cover other stuff is a possible short-term fix, but I suspect there's no political will to do even that.

  4. I'm not saying the following is a solution, but it's an end-point for one type of property. If one owns land on a barrier island and one day the barrier island goes away ... I don't know if we have a legal provision for owning a plot of water (maybe we do for aquaculture) but I think we can safely say that the owners couldn't rebuild.

    I think Steve has the right idea - insurance companies will run the numbers and premiums will reflect the increased probability of major disaster. E.g. I'd guess the cost of insuring a Jersey shore dwelling is about to go way up. That will discourage rebuilding, and lead to some dropping insurance ... and then when the uninsured get hit there will be much less money for rebuilding.

  5. Weather energy is fungible. All the energy in the system affects all the weather in the system. All the weather in the system is affected by all the energy in the system. AGW started affecting the weather as soon as the energy in system rose above natural levels - even if natural levels were subject to some variation.

    Just because in the past we did not detect some AGW energy fluxes and associate changes in weather patterns does not mean that those fluxes and changes in weather patterns did not occur. By the time we started doing reanalysis, we considered some of those weather patterns normal and natural, and thus we did not recognize them as the result of AGW.

    In addition, after WWI, we had a global orgy of plowing virgin grasslands. We tend to treat this as a pristine period, and yet we were changing the albedo of large areas of land, and releasing dust that affected downwind areas. Add the explosion in coal use and coal soot, and the effect is non-trivial.

    As far as the detection of AGW, is concerned, our detection baseline was contaminated. And, the period prior to WW1 is hard to use a detection baseline because of poor standardization of weather stations and equipment.

  6. Pingback: Another Week of GW News, November 11, 2012 – A Few Things Ill Considered

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