Climate Change Brought in for Questioning

Suspect #1, a.k.a. Global Warming, a.k.a. Climate Change, was brought in for questioning regarding its role in our increasingly scary hurricane seasons.

Researchers Greg Holland of the National Center for Atmospheric Research (NCAR) and Peter Webster of Georgia Institute of Technology analyzed a century of storm data to uncover whether the increasing storms and hurricanes in the Atlantic—observed by scientist and layman alike—are a result of natural cycles or human induced climate change. The authors of the study concluded that the frequency of tropical storms are increasing with the rising rising sea surface temperatures (SSTs). In turn, the cause of the warming SSTs looks like human produced greenhouse gases. So it isn't looking too good for C.C. (climate change) who is already up for charges for melting ice in the Arctic, and consequently adding to the mortality of polar bears in the region as well as economic instability for the local humans.

Image courtesy Steve Deyo, ©UCAR

Holland and Webster gathered storm and temperature statistics for the North Atlantic from 1900 to 2005 and found that they had increased in two sharp step functions (around 1930 and since 1995) separated by periods of relative stable activity. (Shown in graphic). They measured an increase in ocean temperature by approximately 0.7 degrees Fahrenheit before each period of increased storm activity. This last period has not yet ended so we could be looking at a few more interesting storm seasons up ahead.

This isn't the first report to link higher hurricane activity with sea-surface temperatures. Now, I haven't checked into every paper published on the subject, by I found at least one other report in Science online here. The paper by Holland and Webster contains a comprehensive list.

This information will no doubt make most of us wonder about Hurricane Katrina and just where we can lay the blame for that one. So far, no one has proven Climate Change to be solely responsible for the storm, as intense storms occur during every natural cycle and the ratio of major hurricanes to tropical storms still sits at around 55%. However, the frequency of these major hurricanes have increased with the increase in overall cyclones. A major hurricane is categorized as having over 110 mph 177 (km/h) winds. Katrina's winds reached up to 170 mph 274 (km/h) and its landfall speeds reached 125 mph (201 km/h).

The full report by Holland and Webster is published online in the Philosophical Transactions of the Royal Society of London on July 30th. A detailed press release from the Georgia Institute of Technology is available here. Tell me if I missed anything.

If you want to learn more about climate change in general, the New Scientist has an interesting roundup of the 26 most common myths about climate change. Check it out.