Climategate: More Science Fiction from the IPCC

I’ve always thought the IPCC should be considered science fiction rather than science. Literally. Jack Vance, described this past summer in the New York Times Magazine as “the greatest living writer of science fiction and fantasy,” used the acronym IPCC in his futuristic Demon Princes novels to represent the Interworld Police Coordination Company -- sort of an intergalactic police force. Our own IPCC -- the Intergovernmental Panel on Climate Change -- does indeed hope to police the world, but aims to free the Earth of carbon dioxide instead of human (and alien) criminals.

Jack Vance’s IPCC is far more connected with reality than ours.

Our IPCC’s latest fantasy concerns hurricanes, a subject of great interest to a resident of New Orleans like myself.

This is the essence of the IPCC Assessment Report 4 (WG1 chapter 3) executive summary on hurricanes:

Intense tropical cyclone activity has increased since about 1970. … Globally, estimates of the potential destructiveness of hurricanes show a significant upward trend since the mid-1970s, with a trend towards longer lifetimes and greater storm intensity. … These relationships have been reinforced by findings of a large increase in numbers and proportion of hurricanes reaching categories 4 and 5 globally. … numbers of hurricanes in the North Atlantic have also been above normal (based on 1981–2000 averages) in 9 of the last 11 years, culminating in the record-breaking 2005 season.

In reality, hurricanes, in both strength and in frequency, have been decreasing over the past four years. Ryan Maue of the Center for Ocean-Atmospheric Prediction Studies (COAPS) at Florida State University, a hurricane researcher, has shown that “global and Northern Hemisphere tropical cyclone activity remains near 30-year historical lows -- three years in a row now of considerably below-average activity globally.”

The decrease is not only in the number of hurricanes, but also in the total energy (ACE) of hurricanes, both in the Atlantic and worldwide, as a graph of hurricane energy vs. time shows:

The hurricane energy has been dropping since 2005, and now is at levels not seen since the late 1970s.

The above figure uses a 24-month running sum. If one instead uses a 12-month running sum, one sees that the average hurricane energy dropped this past summer to the lowest level in 30 years:

The above graphs only cover the past 30 years, so let’s look at northern hemisphere hurricane total energy since 1970, for the months of May, June, and July: