Wed October 31, 2012
Sandy Raises Questions About Climate And The Future
Originally published on Wed October 31, 2012 2:12 pm
If you ask climate scientist Radley Horton, it's difficult to say that Hurricane Sandy was directly caused by climate change, but he sees strong connections between the two. Horton is a research scientist at The Earth Institute at Columbia University. He says that in New York City, the sea level has gone up about a foot over the past century and that researchers expect that rise to continue and even accelerate.
"Given the higher sea levels in the future, even if storms remain exactly the same, we're going to get more frequent flooding events, maybe three times as many coastal flood events by the end of the century, just by virtue of having average sea levels be higher," he tells Fresh Air's Terry Gross.
It's difficult to know whether this year's rise in ocean temperatures was associated with climate change, but Horton says that Hurricane Sandy moved over unusually warm waters in the North Atlantic. "As the planet continues to warm, we expect ocean temperatures to go up," says Horton. "All things being equal, that does give a storm like Sandy more energy."
Horton is also the climate science lead for the science policy team of the New York City Panel on Climate Change, which has worked to prepare the city for climate hazards. He says that because Hurricane Sandy was unprecedented, it's a moment to learn about the many different types of impact a storm can have — for example, flooded subways. "We have several major tunnels with a huge amount of water in them," says Horton. "And even once that water is gone, it's salt water — salt water and electricity do not mix — so it's going to take a lot of time to test some of the electrical signal equipment."
In addition to the damage to cellphones, Internet and electrical equipment in building basements, Horton says the storm also revealed a vulnerability to fires in some of the coastal areas. He asks: "Is that something we fully understood and are there steps that can be taken to augment these heroic efforts that we saw from the firefighting community?"
Horton says another area of future research is the Northeast's long history of industry — much of which reaches back before times of regulation, when hazardous materials polluted the soil. "I think moving forward we just need to research and see if some of those hazardous materials got into floodwater and if it did, are there steps we can take in advance of the next storm to try to prevent that from happening again."
On melting sea ice, and how it can steer hurricanes like Sandy in unusual directions
"We've got approximately half as much sea ice in the Arctic in the fall now as we did say, 30 years or so ago — there's been this dramatic decrease. There is emerging research — my colleagues and I published a paper last February on this — suggesting that as that sea ice melts it's changing the jet stream, a current that steers weather in the mid-latitudes, places like New York. As sea ice melts, our research suggests that the jet stream is going to tend to get weaker. As the jet stream gets weaker, it's easier for storms to stagnate or in some cases, maybe even move to the west, which is what this storm did.
"Most hurricanes, as they get as far north as a place like New York, especially late in the season — September, October — [the] standard pattern is for that strong jet stream to push those storms to the east. What we saw with this storm was that it moved to the west. It's a very unusual track and I would say it's a big research question whether we might see in general more stormy weather and storms taking a track like that as sea ice melts."
On melting sea ice and rising ocean levels
"The melting of sea ice in the Arctic has very little effect directly on ocean levels — because you can think of it really as, ice that's sort of already floating on water. As it melts, it doesn't directly affect sea levels. But there's emerging research suggesting that as the Arctic Sea ice melts, it warms the atmosphere around it. So we need to look at these major ice sheets nearby, especially the Greenland ice sheet, and ask the question of whether the Greenland ice sheet is experiencing warmer air — changes to maybe more rainfall events instead of snow in some parts, and also warmer waters as that Arctic ice melts, as that eroding [of] some of the bases of these ice sheets on Greenland, in ways that make it easier for the land-based ice on Greenland to move to the water. Because if your ice that's on land moves to the water, then you do see an impact in sea level rise. That's emerging research, but I think it's potentially a hazard that could contribute to sea level rise in the future."
On how the New York City Panel on Climate Change helped prepare the city for Hurricane Sandy
"There was a major effort led by Bloomberg to really get a whole group of agencies, private sector companies to the table. And there was a role for experts — everything from climate scientists to risk management experts, members of the insurance community for example. And I think as a result of that process, New York City did document some of the key vulnerabilities and took some specific adaptation steps as well. Adaptation's a process, but some of the key steps that were initiated included beginning the process of elevating some of the key infrastructure, including a wastewater treatment plant in the Rockaways. Steps are being taken to elevate some of those pumps. But you're also seeing a push in the last few years towards these sort of green infrastructure solutions to try to capture rainfall, floodwaters, and also along the coast to sort of buffer the coast through building up of marshes and such to limit the effects of storm surges."