The Big VPIRG Climate Scare 
By John McClaughry

On December 4 Vermonters were treated to a well- orchestrated media event designed to terrify them into endorsing a very expensive special interest policy agenda.

The occasion was the release of a new report by the Vermont Public Interest Group (VPIRG) claiming that "global warming will substantially increase the odds of extreme precipitation. scientists predict that warming temperatures will increase the frequency of major storm with heavy rainfall or snowfall."

And since VPIRG urgently believes that human emissions of greenhouse gases are forcing catastrophic global warming, the report predictably contained all of its policy recommendations as a last desperate effort for humankind to fend off climate disaster.

Those recommendations include land use controls to create dense settlements, mandatory limits on fossil fuel emissions, more expensive renewable electricity from wind and solar, and an interesting item called "stabilizing vehicle travel". This latter category includes incentives or penalties to promote walking, cycling, and public transit riding, to get people out of those awful private cars and trucks.

The report, entitled "When It Rains, It Pours", was prepared by the Environment America Research and Policy Center created by US PIRG with funding from the Pew Charitable Trust. (Imagine the flip side: how much credibility would you give to a report on climate change produced by the National Coal Association?) The key finding of the report for Vermont is a finding that our state "experienced a 57% increase in extreme rainstorms and snowstorms during the period studied" (1948-2006). It turns out, though, that since there were only 15 Vermont stations reporting, the actual increase at the customary 95% confidence level could have been 33% or it could have been 81%.

The report defines an "extreme" rainstorm as a storm that dropped as much precipitation in a 24 hour period as the smallest of the 59 biggest storm days of the 59 years observed, at the 3440 weather stations in the continental U.S. The VPIRG report is silent on this, but the Free Press story reported that the extreme storm threshold for Vermont was 1.51 inches of rain in a 24-hour period. Over the period studied this happened on the average about three times every two years.

Why did VPIRG choose the period 1948-2006? The report says its conclusions rest on the authority of Dr. David Easterling of the National Climatic Data Center. But the 2003 report cited to Easterling covers the period 1895-2000. In it, incidentally, Easterling observed that "[extreme precipitation] frequencies at the beginning of the 20th century were nearly as high as during the late 20th century for some combinations, suggesting that natural variability cannot be discounted as an important contributor to the recent high values." (Emphasis added.)

Former Lyndon State professor of meteorology Joseph D'Aleo offers this explanation: the first half of the period studied was the beginning of the last cold phase of the Pacific Decadal Oscillation, an ocean current pattern that strongly affects storm tracks and thus precipitation over North America. Half way through the VPIRG study period the PDO flipped to its warm phase.  VPIRG carefully picked a period where it could hardly have avoided getting the higher precipitation frequency that it wanted for shock effect.

D'Aleo believes that current global warming (and thus warming-related precipitation) is far more influenced by PDO and other ocean current changes than by any contribution produced by human activity.

The fact that VPIRG and its sister activist groups in other states waited to release the report until the eve of a Senate committee vote on sweeping climate change legislation (emphasized at the VPIRG news conference) adds weight to the suspicion that this report is more a political document than any kind of scientific revelation. The report constantly refers to "global warming pollution" - a favorite enviro characterization of the emission of harmless carbon dioxide from fossil fuel combustion. This lends more weight to that suspicion.

To their credit, the Vermont news media (Free Press, Vermont Press Bureau, WCAX) sought out some expert opinion. Andy Nash, the National Weather Service lead meteorologist at Burlington, was clearly not buying the VPIRG climate fright.  The Free Press reported Nash as observing cautiously that the data could be artifacts of the natural variability of the weather. WCAX quoted Nash as saying that the report does not present new data and raises more questions than it answers.

This won't be the last time that enviro organizations pump up an enviro-scare to promote their political agenda. Vermonters need to greet these continual revelations with a lot of skepticism.
 

John McClaughry is President of the Ethan Allen Institute