For decades now, scientists have warned that global warming will result in more frequent and powerful storms, and that rising seas will exacerbate the damage they cause. Unfortunately, it has taken Hurricane Katrina and the destruction of a major metropolitan area to really bring home to the public what that really means: the potential for death and destruction of truly Biblical proportions.
Global warming didn’t cause Katrina, of course, but it didn’t help matters any. Just weeks before Katrina hit, the journal Nature published new research showing that Atlantic hurricanes have more than doubled in power since 1970, fueled by warmer water and atmospheric conditions. Southwestern Louisiana is also experiencing the greatest relative sea-level rise in the nation – three feet a century – due to a combination of sea-level rise and destructive effects of separating the bayous from the Mississippi with levees. As the bayous surrounding New Orleans have turned to open water, the city has grown more vulnerable to the effects of a major storm, a situation I described years ago in Ocean’s End.
So what does global warming have in store for coastal Maine and what effect, if any, are higher temperatures having here?
Fortunately, Maine’s rocky shores afford a certain degree of storm protection, but not as much as you might think. Joseph Kelley, a marine geologist at the University of Maine in Orono, is conducting a vulnerability assessment of the Maine coast and has found that 53 percent of the shoreline actually consists of unconsolidated bluffs of marine clay, essentially dried out ocean mud.
“More than half the ‘rockbound’ coast of Maine is actually a ‘mud-bound’ coast that is teetering on the edge of a rising sea,” Kelley says. In storms these clay bluffs – characteristic of the shores of Falmouth, Cumberland and Brunswick – are prone to landslides, like the one that wiped out two homes on Rockland harbor in 1996. He says rising sea levels undercut the bluffs, eventually causing a collapse.
A 1995 study by the U.S. Environmental Protection Agency predicted that the beaches of southern Maine would see their shorelines retreat by between eight and 50 meters if sea levels rise by one meter, the “middle” scenario predicted by the International Panel on Climate Change, and twice that with a two-meter rise. At Ferry Beach in Scarborough, the study predicts that the latter scenario would result in the inundation of 260 acres of land, including 350 structures.
“In reality, it’s the storms that do the real ‘clean up’ with sea level rise,” Kelley says. “The next big storm will cause large scale damage to the southern Maine coast, just as it did in Louisiana.”
Climate change impacts aren’t expected to stop at the shore. Jennifer Andersen of the Natural Resources Council of Maine marshals a wide array of circumstantial evidence that global warming is already effecting the state: decreased snowfall, warmer winters and hotter summers; the spread of ticks and forest pests that cold winters once kept at bay, more summer smog, and the early onset of both maple sap runs and the annual ice-outs in our lakes and ponds.
“We feel the warning signs are out there, but that it’s not too late to do something about it,” she says. Her organization has long called for improvements in energy efficiency and the increased use of renewable energy sources, and successfully campaigned for the adoption of legislation that will expand the number of hybrid vehicles on Maine roads. They also support Maine’s participation in the Northeast Regional Greenhouse Gas Initiative, under which nine states will cap power plant emissions of greenhouse gases and allow the plants to trade surplus carbon allowances amongst themselves.
“Because there has not been a lot of leadership from the federal government, states have had to step up to the plate and take action,” Andersen adds. “We can turn things around.”
But David Vail, who teaches environmental economics at Bowdoin College, isn’t quite as upbeat. “This is a global phenomenon and the actions that can be taken in a local jurisdiction – especially one as small as Maine – are just not going to have a significant effect on the problem,” he says. “Any realist would say that ultimately the policy needs to come from Washington if we are going to have any real impact.”
That said, Vail supports efforts that would reduce greenhouse gas emissions in the state, not least because the policies would have all sorts of additional benefits. “We would reduce emissions of other pollutants at the same time, and conservation investments” – more efficient insulation, air conditioners, power plants, and automobiles, for instance – “have a high economic return beyond their environmental benefits.”
One hopes it doesn’t take another Katrina-like disaster to prod Congress and White House into recognizing those facts as well.
– Colin Woodard is the author of The Lobster Coast: Rebels, Rusticators, and the Struggle for a Forgotten Frontier and Ocean’s End: Travels Through Endangered Seas. He lives in Portland and has a website at www.colinwoodard.com.