More On Climate Change And Superstorm Sandy

Here’s another analysis, from Washington Post Capital Weather Gang blogger Jason Samenow, that is both balanced and detailed. Based on what we know about Sandy, and the scientific literature, here are his five big takeaways:

1) Sandy should not be “blamed” on climate change. Climate change does not cause storms and did not cause Superstorm Sandy. Storms form when certain weather ingredients come together. The historic record shows violent storms, some even more severe than Sandy, have struck the Northeast repeatedly..

2) While climate change did not cause Sandy, it may have been a performance enhancer like a steroid, injecting it with somewhat more energy and power.

3) Sea level rise from manmade climate change increased the water level along the Northeast coast 6 to 8 inches and, as a result, somewhat worsened the coastal flooding from Sandy.

4) There is speculation that decreased Arctic sea ice from manmade climate change altered atmospheric steering currents, strengthening the weather system in the North Atlantic that helped to push Sandy ashore in the Northeast. This idea is controversial.

5) Climate change is likely to slowly increase the intensity of hurricanes in the future, but trends in storm frequency are less certain and the number of storms may actually decrease. Sea levels will continue to rise adding to the coastal flood risk.

He goes on to examine each of these in detail, and includes lots of links to research and related articles. So if you want the full monty on Sandy and climate change I urge you to read the whole thing.

Superstorm Sandy And Global Warming II

Already getting some pushback from wannabe deniers, so I thought I would put this analysis from Scientific American out there as well. The key section:

The hedge expressed by journalists is that many variables go into creating a big storm, so the size of Hurricane Sandy, or any specific storm, cannot be attributed to climate change. That’s true, and it’s based on good science. However, that statement does not mean that we cannot say that climate change is making storms bigger. It is doing just that—a statement also based on good science, and one that the insurance industry is embracing, by the way. (Huh? More on that in a moment.)

Scientists have long taken a similarly cautious stance, but more are starting to drop the caveat and link climate change directly to intense storms and other extreme weather events, such as the warm 2012 winter in the eastern U.S. and the frigid one in Europe at the same time. They are emboldened because researchers have gotten very good in the past decade at determining what affects the variables that create big storms. Hurricane Sandy got large because it wandered north along the U.S. coast, where ocean water is still warm this time of year, pumping energy into the swirling system. But it got even larger when a cold Jet Stream made a sharp dip southward from Canada down into the eastern U.S. The cold air, positioned against warm Atlantic air, added energy to the atmosphere and therefore to Sandy, just as it moved into that region, expanding the storm even further.

Here’s where climate change comes in. The atmospheric pattern that sent the Jet Stream south is colloquially known as a “blocking high”—a big pressure center stuck over the very northern Atlantic Ocean and southern Arctic Ocean. And what led to that? A climate phenomenon called the North Atlantic Oscillation (NAO)—essentially, the state of atmospheric pressure in that region. This state can be positive or negative, and it had changed from positive to negative two weeks before Sandy arrived. The climate kicker? Recent research by Charles Greene at Cornell University and other climate scientists has shown that as more Arctic sea ice melts in the summer—because of global warming—the NAO is more likely  to be negative during the autumn and winter. A negative NAO makes the Jet Stream more likely to move in a big, wavy pattern across the U.S., Canada and the Atlantic, causing the kind of big southward dip that occurred during Sandy.

And I suppose I should also add this analysis by NASA’s James Hansen, who has studied (and worried about) climate change more than any scientist on the (warming) planet. Here’s the guts of what he has to say:

In a new analysis of the past six decades of global temperatures, which will be published Monday, my colleagues and I have revealed a stunning increase in the frequency of extremely hot summers, with deeply troubling ramifications for not only our future but also for our present.

This is not a climate model or a prediction but actual observations of weather events and temperatures that have happened. 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. To the contrary, our analysis shows that, for the extreme hot weather of the recent past, there is virtually no explanation other than climate change.

The deadly European heat wave of 2003, the fiery Russian heat wave of 2010 and catastrophic droughts in Texas and Oklahoma last year can each be attributed to climate change. And once the data are gathered in a few weeks’ time, it’s likely that the same will be true for the extremely hot summer the United States is suffering through right now.

The resistance to both the logic and the science of global warming and weather is stupefying to me. But not surprising, sadly. We are a species that is sleepwalking through history.

Nightly Reader: Nov. 7, 2012

1) Hope And Change? Honestly, I’m more interested in change. But I’m glad to hear mention of the climate (FINALLY!), and I sincerely hope that the aspirations and ideals expressed so beautifully in this speech translate into true leadership and a kickass political strategy that leads to a real shift in what America cares about, and what sacrifices America is willing to make for the global good.

2) Annals Of Inexplicable Subsidies: Does federal flood insurance, which encourages people to build in vulnerable locations, make any sort of sense anymore? Not really.

3) Deja Vu All Over Again: Another week, another brutal storm for the Northeast. This one with wind, rain, AND snow.

BONUS VIDEO(S): Nine awesome TED Talks which aim to show you nature from a different perspective or in a different light.