I've been asked many times in the past 24 hours if climate change was the cause of the superstorm/post-tropical cyclone named Sandy. The answer is simple: Yes ... partially.
While there certainly have been other late-season hurricanes in the past — the "Perfect Storm" of 1991 or the "Long Island Express" of 1938 — the way in which Sandy came together with two other fronts is something new, and indicates the type of volatility we should begin to expect as our climate warms up.
Just listen to the way experts have been attempting to describe this new type of superstorm:
- Jim Cisco, forecaster at NOAA: "Frankenstorm"
- Stu Ostro, chief meteorologist at Weather Channel: "mind-boggling"
- Dylan Dreyer, NBC meteorologist: "There is just no word for it"
- Carl Parker, forecaster Weather.com: "This has never happened before"
Though Sandy is remarkable, scientists have been reluctant to firmly apply the "climate change" stamp to Sandy. Why? The area of climate research known as "attribution" (which looks for cause & effect relationships between long-term climate systems and short-term weather systems) is a very new field, made possible only recently by better data and better computers. Because attribution is a new field, it is impossible for scientists to make 99 percent certainty claims about anything. But in just the past few years very, very strong connections have emerged.
Here are a few key facts about what's happening to the climate in our region:
- 2012 broke all known records for melting of Arctic sea ice
- Melting Arctic sea ice increases sea level rise
- Seas in the Northeast U.S. are rising 4 times faster than the global average; they are a full 7 inches higher than in 1912
- Higher sea levels mean far greater flooding impacts in low-lying urban areas
- Melting Arctic ice also creates negative pressure in the jet stream, forcing large cold air fronts to move south
- The Sandy superstorm gained its lethal power due to a large cold air front from the north
- Temperatures in the Northeast are 5 degrees warmer than usual
- Warmer seas allow tropical storms to acquire more moisture than usual (PDF)
- The Sandy superstorm gained its massive size from a huge amount of moisture collected in the Atlantic
Make of it what you will. But you can see why people like New York Gov. Andrew Cuomo have begun to finally call attention to the extremity and frequency* of extreme weather events:
There’s no such thing as a 100-year flood ... we have a 100-year-flood every two years now. These are extreme weather patterns. The frequency has been increasing ... Anyone who says there's not a dramatic change in weather patterns I think is denying reality.
Many have attempted to describe the role of climate change on the formation of major storm events by using an analogy to the use of steroids in sports. Check out Seth Meyers explaining it to Jimmy Fallon last night. Can you say that steroids were the reason Barry Bonds hit so many home runs for the Giants? Well yes ... partially. You can look at the historic record and then compare that record to a spike in performance to see the difference. Here's a good video recap:
But as the science becomes more clear, and as we see more and more extreme weather events like drought, extreme precipitation, coastal flooding, and record storm seasons, some experts are saying this steroid analogy is not sufficient in describing the pivotal role climate change plays in extreme weather. As James Hansen of NASA's Goddard Institute for Space Studies has said:
Our analysis shows that it is no longer enough to say that global warming will increase the likelihood of extreme weather and to repeat the caveat that no individual weather event can be directly linked to climate change.
As we clear through Sandy's wreckage in the weeks to come, the consequence of NOT addressing this possibility — that climate change is, as scientists have warned for decades, a primary driver of extreme weather events — will become an all-too-painful reality for us. Then, maybe then, our politicians will set aside their differences and get to work on the greatest problem mankind has ever faced.
*Note: Scientists have been particularly reticent in making claims about the frequency of storms. The IPCC has documented some research that shows we may be seeing MORE storms, but the more widely accepted fact is that climate change increases the severity of storms, not necessarily the total number of storm systems in a given season.
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