Carbon-Based

Darrell Moellendorf in Policymic: When someone at the National Oceanic and Atmospheric Association last week referred to the confluence of Hurricane Sandy with a polar trough just before Halloween as “Frankenstorm,” it may have been largely due the storm’s intensity and timing. But “Frankenstorm” produces another association. This monster, like the one in Mary Shelley’s novel, may have been human created.

The Intergovernmental Panel on Climate Change (IPCC), summarizing data gained from countless observations, has reported that over the hundred-year period from 1906 to 2005, the average global surface temperature increased 0.74°C. Although the oceans have warmed less quickly than land areas, they have been taking in over 80% of the heat being added to the climate system. Warm ocean waters are the energy supply for cyclones. This is why such storms lose force when they run aground. And according to the IPCC, “There is observational evidence of an increase in intense tropical cyclone activity in the North Atlantic since about 1970.”

Has the warming of the oceans caused more intense tropical storms? Are greenhouse gas emissions the creator of a Frankenstorm? Oceanic warming is consistent with intense tropical storms, but it is not possible to run the kind of test needed to infer causation in any particular case with a sufficient degree of certainty. British philosopher John Stuart Mill described a “method of difference” to determine if a certain factor caused an event. Remove the factor, keeping the other factors in place, and see if that leads to an alternative outcome. But we cannot re-run history over the last 150 years and take CO2 emissions out to make the comparison with today. And even if we could, many other things would be very different without a coal-powered industrial revolution.

Intense tropical cyclones would presumably have formed in the absence of the current warming of the oceans by the greenhouse effect. Maybe Sandy would have been one of those. But the fact is that Sandy is not one of those, but one that formed after the ocean had warmed due to human activity. And Sandy follows a summer of record heat waves and droughts in the United States and polar ice retreating to its lowest ever recorded level...

Aerial views of the damage caused by Hurricane Sandy to the New Jersey coast taken during a search and rescue mission by 1-150 Assault Helicopter Battalion, New Jersey Army National Guard, Oct. 30, 2012. (This appears to be Casino Pier, Seaside Heights, New Jersey.)