Many researchers and climatologists are getting asked this same question ad nauseum. Most are quick to say that ‘Yes, this storm could have formed without any relating effects from rising CO2 levels, BUT, most likely climate change did play an exacerbating role.’ Ultimately, many elements went in to creating this deadly and damaging storm, so which of those did climate change have an effect on?
First, let’s look at how hurricanes form. Hurricanes are like giant engines using warm and wet air as their fuel. The warmer the surface of the ocean, the more water vapor there will be in the air causing the resultant storm to be more powerful. As this warm air rises it creates a low pressure system in the air below. The higher pressure and cooler air surrounding the system pushes in and begin to rise creating a swirling motion, which we recognize as a hurricane. For a more detailed look at how a hurricane forms, visit NASA: Hurricane Formation
So, what can we say about climate change and its effects on Hurricane Sandy? Rising CO2 levels have created increased melting of ice sheets in the poles and warmer sea surface temperatures. Both of these factors of melting ice and thermal expansion have contributed to sea-level rise, and could have caused Sandy’s record breaking storm surge of 13.2 feet. According to climatologist Michael Mann of Pennsylvania State University, “At least 1 foot of those 13.2 feet was arguably due to sea-level rise,” he said. This is because sea level is at least 1 foot higher than a century ago. Sea Surface temperature also had a role to play. Due to the warmer than usual temperature in the Atlantic there was more water vapor in the air, intensifying the storm and producing heavier rainfall.
Typically as hurricanes move northward the colder water weakens the hurricane, but anomalous warmer sea surface temperatures in the North prevented this from happening. Dan Satterfield, a meteorologist at CBS affiliate WBOC TV writes on his blog at the American Geophysical Union, “What meteorologists like myself, and climate researchers are talking about is the huge blocking high over Greenland. October or November hurricanes re-curve into the Atlantic because of a much stronger fall jet stream, but the Greenland block turned Sandy into the coast. The track of Sandy was very RARE.” He gives more detailed information on the post-mortem of Sandy’s track on his blog.
The most accurate statement we can make about Climate Change and Hurricane Sandy’s relationship is that it has given us insight in to the kind of storms climate change will make more likely. And hopefully sandy’s aftermath will bring the conversation about Climate Change mitigation and adaptation back to the forefront of American consciousness. If you are interested in this conversation visit the Earth Institutes State of the Planet blog where several climate insiders discuss Sandy’s impacts and the goals we must set to prepare ourselves for the likelihood of these strong storm events.
