Hurricane Sandy's the hurricane from hell. It broke all records. It was the storm of the century. It is the hurricane we will tell our grandkids about.
But can it happen again? This depends on the science behind the storm. Hurricane Sandy was unusual because it involved the collision of three air masses. First, you had a medium sized hurricane coming in from the Atlantic, feeding off the warm waters of the Gulf. Then you had an unusual jet stream pattern, carrying ice-cold Arctic air from the north polar region down to Florida, colliding with the hurricane. Third, you had a low pressure storm coming in from the west.
By themselves, none of these three could cause much damage. But together, they morphed into a giant superstorm that caught scientists by surprise. Computer programs are not very good at modeling the collision of two air masses, and simulating the collision of three air masses is even more difficult.
Is this related to global warming? First, there is no smoking gun, no conclusive evidence that points to global warming, which is an average effect, measured over many years. However, the signs are not good.
Second, global warming is heating up the Gulf waters, and warm water is the basic energy source driving a hurricane. More warm water means, in principle, more energy for a hurricane. But hurricanes also derive energy from the temperature difference between cold and warm air. The unusual collision with the jet stream from the Arctic also helped to feed the hurricane. And the fact that the north polar regions are changing (e.g. 50% decrease in thickness of north polar ice in the last 50 years, the recession of ice in Greenland and Alaska, thawing out of tundra, etc.) means possible changes in the jet stream.
So it is possible (although not 100% certain) that the warming of the earth can cause hurricanes of greater intensity.
Global warming is actually a misnomer. It should be called global swings, so that we can have droughts, flooding, forest fires, etc. happening at the same time in different points of the earth. So global warming is actually the weather on steroids. This is consistent with the 100 year floods, 100 year forest fires, 100 year droughts that we seem to have every few years.
So is this the new normal? We cannot say with certainty, but a case can be made that this wacky weather is, in part, driven by global warming.
Image courtesy of Shutterstock.