Northeast Floods Stir Global Warming Debate
by: Jason Szep 29 June 2006
BOSTON (Reuters) - Images of swamped homes in the U.S. Northeast deepened suspicions over global warming, giving ammunition to scientists and others who say greenhouse gas-spewing cars and factories are fueling extreme weather.
Meteorologists cautioned that no one should read too much into one storm. But the Atlantic Ocean is unusually warm for this time of year, they said, creating excess moisture in the atmosphere that can swiftly build a powerful rainstorm.
Paul Epstein, associate director of Harvard Medical School's Center for Health and the Global Environment, said the Atlantic is warming faster than scientists projected even a decade ago, and he expects such storms as the one seen this week from Virginia to New York to become common.
"Scientists and climatologists are looking at one another and we're just stunned because no one, even in the 1990s, projected the magnitude of the storms and degree of warming in the Arctic that we are seeing," he said.
Epstein sees a clear pattern: rain has increased in the United States by 7 percent in three decades; heavy rain events of more than 2 inches a day are up 14 percent and storms dumping more than 4 inches a day rose 20 percent.
The floods that forced up to 200,000 evacuees from a historic Pennsylvania coal town on Wednesday followed a year of erratic weather in other parts of the region, including record rainfall in May and June in Massachusetts, a spring-like January in Maine and Vermont's worst autumn foliage in memory.
On February 12, Boston dug itself out of its largest snowfall for a single day when 17.5 inches fell -- an abrupt change from the second-warmest January on record in much of New England. Rhode Island's January was the warmest in 56 years.
In Maine, lakes froze later, then thawed, faster than many could remember.
Most scientists say greenhouse gases could cause huge climate changes like floods, heat waves, droughts and a rise in sea levels that could swamp low-lying Pacific islands by 2100.
But not everyone blames human pollution for drenching the U.S. Northeast.
"The climate is warming," said Bernie Rayno, senior meteorologist at Accuweather.com. "The real question is: 'Are humans causing it or is it occurring because of natural cycles?' We believe that we are in a natural cycle like we were back in the 1930s, 40s and 50s. And that was a time of big climate swings."
Brenda Ekwurzel of the Union of Concerned Scientists sees a gradual shift over the past 50 years toward heavier rain and more violent weather, including the record-shattering hurricane season that produced 28 storms last year.
"We do expect to see an increase in the intensity of rainstorms particularly in the Northeast," she said.
At current projections, Epstein said, a typical day in Boston could feel like present-day Richmond, Virginia, in 100 years under one model of the atmosphere and oceans produced by the federally funded New England Regional Assessment of 2001.
Epstein, who contributed to that study, said another model that sees Boston resembling Atlanta, Georgia with a 10-degree Fahrenheit (5.6-degree C) rise in temperature over a century could be conservative.
"What we are seeing is really the pace and magnitude of these changes are much greater than we had imagined, so in fact the models each year become underestimates," he said.
The Insurance Information Institute, a nonprofit trade group, said the Northeast looked "woefully unprepared" to the risk of floods. "We're entering a period of time when we should expect more severe and frequent hurricanes and at the same time we've got this trend toward more and more people moving into coastal areas," said spokeswoman Jeanne Salvatore.
"The risk is a lot higher than most people anticipate."