From the darkened living rooms of Lower Manhattan to the wave-battered shores of Lake Michigan, the question is occurring to millions of people at once: Did the enormous scale and damage from Hurricane Sandy have anything to do with climate change?
Hesitantly, climate scientists offered an answer this week that is likely to satisfy no one, themselves included. They simply do not know for sure if the storm was caused or made worse by human-induced global warming.
“We’re changing the environment — it’s very clear,” said Thomas R. Knutson, a research meteorologist with the government’s Geophysical Fluid Dynamics Laboratory in Princeton, N.J. “We’re changing global temperature, we’re changing atmospheric moisture, we’re changing a lot of things. Humans are running this experiment, and we’re not quite sure how it’s going to turn out.”
By the time Hurricane Sandy hit the Northeast coast on Monday, upending lives across the Eastern half of the country, it had become a freakish hybrid of a large, late-season hurricane and a winter storm more typical of the middle latitudes. Though by no means unprecedented, that type of hybrid storm is rare enough that scientists have not studied whether it is likely to become more common in a warming climate.
Winds knocked out power as far west as Michigan. But the most serious damage, including the flooding of New York’s subway tunnels and the broad destruction along the Jersey Shore, came as the storm pushed roiling ocean waters onto land, a phenomenon known as storm surge. The surge set records in some places, including the Battery in Lower Manhattan.
Globally, the ocean rose about eight inches in the last century, and the rate seems to have accelerated to about a foot a century.
Scientists say most of the rise is a direct consequence of human-induced climate change. Ocean water expands when it warms, accounting for some of the rise, and land ice is melting worldwide, dumping extra water into the ocean. Scientists say they believe the rate will accelerate further, so that the total increase by the end of this century could exceed three feet. (Source)