Conservators Annual Dinner Meeting
May 28, 2008
Dukes Tells Conservators:
Heat Wave Coming
The atmosphere is heating up, we all know. The question is how much. Professor Jeffrey Dukes of UMass Boston, speaking at the Newton Conservators' annual meeting on May 28, discussed global temperature trends, 50- and 100-year forecasts, the causes of global warming, some potential cures, and the likely damages to New England along the way. He answered the question: how fast is global warming happening? Faster, he says, than was forecast in even the worst-case projections.
Professor Dukes, the recipient of a National Science Foundation grant for his current experimental field work in Waltham, cited statistics from the Union of Concerned Scientists and others. The most startling of these was the track record of the projections themselves. Scientists make best- and worst-case scenarios for temperature trends, given the amounts of heat-trapping gases that are expected to be emitted. The best-case scenario shows a gradual warming. The worst-case scenario shows a steeply climbing temperature trend. And in each of the two most recent years for which data are available, actual temperatures have exceeded the temperatures predicted in even the worst-case scenarios.
Carbon dioxide is the most important of the heat-trapping, or greenhouse, gases. Methane is emitted from cattle, and nitrous oxide is produced in wet environments such as rice paddies and cattle waste lagoons. Human activity, including farming and the burning of fossil fuels, has resulted in an increase of CO2 in the atmosphere of roughly 50% in the past 10,000 years. The amount of CO2 that we put into the atmosphere annually is relatively small in comparison to emissions from natural sources. But it is enough to tip the scales in favor of greatly increased warming.
Warming can be expected to be greatest at the poles and least near the equator, with an average annual temperature increase of 7 degrees at the poles. Winters will become wetter in the northern hemisphere. New England can expect an increase in precipitation of 10% to 20% in 50 to 100 years. Egypt, already dry, will become dryer. Along with the increased rain will come greater extremes, with rain falling in larger storms, separated by longer periods of drought.
Massachusetts can expect an average annual temperature increase of 5 to 11 degrees by 2100. The climate of Massachusetts will become more like today's climate in Maryland or Georgia. Our winters will see much less snow cover. Growing seasons will be a month or more longer. Species that today are prevented from surviving in New England because of extreme cold temperatures will enter the region. The wooly adelgid, kept in check throughout much of New England because of its inability to survive deep freezes, will no longer be frozen out, and hemlocks, the adelgid's favorite food, are likely to die off. The same goes for sugar maples. The bright colors of fall will become dull.
Professor Dukes has established the Boston Area Climate Experiment at a field station in Waltham. There, he and a group of volunteers subject small patches of ground to the climate conditions that are projected for New England's near future. The station could use additional volunteers.
Can we stop climate change? Professor Dukes' answer is "yes." But to do so takes will. His advice: eat less meat. And elect leaders who will take on the challenge, rather than put it off to another day.
- Eric Reenstierna