Sunday, July 25, 1999

Climate of change
By MEREDITH GOAD, Staff Writer
Copyright © 1999 Blethen Maine Newspapers Inc.

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It's the year 2100, and the temperature in Maine has inched up 4 degrees Fahrenheit over the last century. It doesn't sound like much, but consider that during the last ice age it was just 5 to 9 degrees colder than it is now.

Four degrees warmer is enough to change the very face of Maine.

The Ice Storm of '98, for example, doesn't seem like such a fluke now. Maine's traditionally harsh winters are much milder, and the ski and snowmobile industries are suffering.

Spring arrives a few days early, but there's not much of a maple sugaring season because the maple trees are slowly migrating northward into Canada. The mornings are much quieter because Maine has lost almost 40 percent of its songbirds as they follow the spruce-fir forests north. The lack of hard frosts and the dearth of maples has muted the colors of autumn, and more tourists are now flying to Canada to go leaf-peeping.

This may be the Maine of the future, scientists say, if the planet heats up as they expect it will because of global warming. Not all will be gloom and doom, but things will be different. And the changes may start happening much sooner than we anticipate — not in centuries but within our lifetimes.

Over the next century, the amount of carbon dioxide, one of the greenhouse gases that fuels global warming, is expected to at least double in the atmosphere. The resulting ice storms, floods, droughts and other consequences of that doubling may affect everything from agriculture and forestry to public health in Maine.

"We're changing the chemistry of the entire Earth by a factor of two or quite possibly more than that," says Dr. George L. Jacobson Jr., director of the Institute for Quaternary Studies at the University of Maine. "Now how smart can it be for us as human beings to change the atmosphere of the whole Earth? How can we possibly assume nothing will happen?"

Jacobson and his colleagues worry that the public isn't paying enough attention to global warming and that New Englanders won't be prepared for the changes it will bring. It's time to start thinking about what those changes might be — good or bad, Jacobson says, and begin planning for them. People and industries are making decisions today with long-term consequences — the trees that are being planted now, for example, may be maturing under different climatic conditions — and they need to start factoring climate change into their plans.

The 1990s were the warmest decade of the millennium. Some people still think scientists haven't reached a consensus on whether or not this warming is real. Others are simply overwhelmed by the topic and assume it won't be an issue until long after they're dead and buried.

But scientists examining gas bubbles trapped in glacial ice have found that natural climate changes can occur more quickly than they previously thought. Some of the most dramatic changes have occurred in less than 25 years, and these abrupt changes are sometimes preceded by periods of instability — fluctuations in temperature and extreme weather events much like what we're experiencing now.

That, combined with worldwide signs that climate is changing — glaciers shrinking by 11 percent, birds and butterflies moving northward, tropical disease crossing northern borders, Alaska salmon dying in the warming waters of the Pacific — has made scientists increasingly worried.

"It's very high risk," said Don Anderson of the Maine Department of Environmental Protection, who traveled to Washington recently with a group of scientists to urge Congress to take action. "Is it absolutely proved? No."

Most mainstream scientists now do agree that the Earth is warming, although there is still a lot of uncertainty about just how much it might warm in the future and how quickly it might happen. And no one knows for sure yet how climate change might affect precipitation patterns around the globe.

"There are scientific uncertainties out there, and we will probably always have scientific uncertainties," said Barry Rock, director of the Complex Systems Research Center at the University of New Hampshire. "But I don't feel that the levels of uncertainty warrant inaction. I really feel that there's enough indirect evidence now that we should start taking this seriously. This isn't something that we can just assume the next generation is going to deal with, or that it probably isn't going to happen. We need to take it seriously, and we need to open a dialogue."

CO2 levels take off

Since the 1800s, "CO2 levels have risen by 30 percent, and they're rising at approximately 1 percent per year, which is a disturbing trend," Rock says. "Methane has doubled from what it was in pre-industrial times."

In 1995, scientists estimated that the buildup of these gases will increase the mean global surface temperatures of the Earth by 1.4 to 6.3 degrees Fahrenheit by the end of the next century. New estimates — preliminary but peer-reviewed — now say the temperature increase will be slightly higher, from 2.3 to 7.3 degrees.

Such an increase would have different effects on different parts of the planet. Some places would be drier, for example, some wetter. Exactly what will happen on a local level is hard to say because regional predictions are much less reliable. But there are some preliminary forecasts that have been made.

Scientists say Maine could see an increase in temperature of 2 to 8 degrees Fahrenheit and a sea-level rise of up to 20 inches. The changes that kind of temperature increase might bring to the state may be good or bad, depending on the point of view, but all will require some level of adjustment.

Since 1950, notes Paul Epstein, associate director of the Center for Health and Global Environment at Harvard Medical School, winter nighttime temperatures have been going up twice as fast as the overall rise in temperature.

"Warm winters can contribute to overwintering of ticks and mosquitoes, and warm, wet summers and springs can give rise to large populations of these insects," Epstein said.

That translates into an increased potential for insect-borne diseases in New England such as Lyme disease, eastern equine encephalitis and even malaria.

"In the United States in the 1990s, we've seen locally transmitted malaria in Michigan, California, in Toronto last year, in Queens, New York, in New Jersey and in Florida," Epstein said. "And in the 1980s, we saw locally transmitted malaria only in California. This is definitely consistent with the projections that (during global warming) higher latitudes may begin to see malaria and may have conditions conducive to the transmission of malaria."

Spring is now coming six days earlier, and fall five days later. As the pollen season continues to expand, "one big question is, are we setting ourselves up for more hay fever and asthma," said Epstein. Warm winters also mean more ice storms like the one in 1998 that sent hundreds of people to Maine hospitals.

"There was a dramatic increase in lung disease, respiratory illnesses like asthma and cardiac disease complaints, and carbon monoxide" poisoning, recalled Dr. Dora Mills, director of the Maine Bureau of Health.

Hot, sticky days with high temperatures speed up the formation of ground-level ozone, which can exacerbate heart and lung diseases. The Maine Bureau of Health has issued alerts about dangerous heat and ozone levels during the past two summers, something that was previously "extraordinarily rare," Mills said.

Effects of rising sea level

Depending on where you live on the planet, sea level is expected to rise anywhere from 7 to 39 inches. Large chunks of Florida and Louisiana, including New Orleans, are expected to disappear eventually. In Maine the effects will be less severe and gradual enough that — except for people living in vulnerable places like Wells, Camp Ellis or Higgins Beach — communities will be able to adjust.

"The greatest extent of sea-level rise is going to be in Down East Maine, but that's obviously a rocky shoreline and least developed," said Suzanne Moser of the Kennedy School at Harvard, who has studied community responses to sea-level rise in Maine. "In southern Maine you have the beaches — not a lot of miles, but you have a lot of development there, a lot of population there. Generally speaking, the southern Maine communities are going to notice it most strongly in increased erosion, wetland inundation, maybe some saltwater intrusion into their water resources."

While Portland likely will be built up higher, low-lying communities will have to learn how to protect themselves by doing some of the same things they do to prepare for severe storms, notes Joseph Kelley of the University of Maine Department of Geologic Sciences. That's because it's the storm surges that actually will cause the most damage.

"Sea-level rise is not in and of itself going to swamp our beaches and remove them," Kelley said. "It is the silent partner."

Although the sea will rise slowly, it's wise to begin thinking about the issue now, Kelley says, especially in regard to long-range planning of public infrastructure. For example, the town of Ogunquit has built a sewage treatment plant right on the beach.

"That's probably not the best place for a sewage treatment plant in a long-range sense because sea level is rising and sooner or later they're going to have to do something about that plant," he said.

Nature may have a harder time accommodating the rising waters. Wetlands will drown if they can't retreat inland because of development.

Wetlands serve as nursery areas for many species of fish and shellfish. They also help to maintain water quality by trapping sediments, and they are a major food source for New England's already ailing fishery.

"One of the really important things about salt marshes is that the plant material that grows in a salt marsh basically dies back every year and is transported by the tides into the Gulf of Maine food chain," said Stewart Fefer of the U.S. Fish and Wildlife Service. "So it's an important nutrient source for the food chain." Spruce, fir displacement Maine's forests will also experience change. Southern hardwood forests could creep northward, displacing spruce and fir by as much as 40 percent to 50 percent. That has obvious implications for the forestry industry in Maine.

If it becomes substantially drier, forests in some areas of the state could be replaced by grasslands.

As the vegetation changes, so will the wildlife that relies on it.

Jeff Price, director of climate change impact studies at the American Bird Conservancy, works with computer models to examine how bird populations might shift during global warming. His calculations show that by 2100 Maine will experience a net loss of 23 percent of its warbler species alone.

"And that's turnover, so that takes into account species from Massachusetts and Pennsylvania moving into Maine," he said. "But if you look at it in terms of what Mainers think of as 'their' birds, the loss is 53 percent."

Broaden it to all songbirds, and there's an 11 percent net loss and a 36 percent gross loss. Birds that will no longer live in Maine at all include the olive-sided flycatcher, yellow-bellied flycatcher, winter wren, Tennessee warbler, Nashville warbler, Cape May warbler, bay-breasted warbler, pine siskin, evening grosbeak and dark-eyed junco.

Southern birds that will move in to colonize Maine or increase their range here include the northern bobwhite, white-eyed vireo, cerulean warbler, northern cardinal, eastern bluebird, Kentucky warbler and orchard oriole.

Why worry about losing a little of the costume jewelry of the forest?

"All warblers are insectivorous, and you've got all three of the species that eat spruce budworm," Price said. "You have huge expanses of forests that are prone to pest outbreaks. This is not the entire pest control system, but this is a major part of the natural pest control system that is likely to break down."

Coldwater fishing is also likely to suffer if the climate warms. About 50 percent of the country's rainbow trout fishing areas are expected to be lost as the planet warms, according to Frank Rahel of the University of Wyoming.

Brook trout could be lost from much of southern New England, Rahel said at a global warming conference in Vermont. Where populations remain, they will be small and fragmented, a precursor to extinction.

Brook trout are ancient, coldblooded creatures that evolved in the northern climes and can't survive a water temperature beyond 75 degrees. Maine has 1,103 brook trout lakes and ponds, and 30,000 miles of brook trout streams. The fish became isolated in these areas after the last glacier retreated from the landscape.

"We do have a lot of brook trout populations now where the temperature is marginal," said Forrest Bonney, a state fisheries biologist. "There are a lot of pond situations where the water temperatures are essentially too warm for trout, but they're able to get by during warm periods because there are springs or some thermal refuge. So I think there is a real potential for loss. I don't think it would take much of an increase in temperature to lose these populations in marginal habitats."

Of course that doesn't mean that fishing would be gone for good.

"After climate change we're not going to have fishless lakes and streams by any means," Rahel said. "We're going to have more warmwater species. Those species are pretty adaptive and they'll extend their range, so we'll have species like walleye and perch instead of things like brook trout."

Dynamic range changes

Southern Maine wildlife that is now at the northern limit of its range — spotted and Blanding's turtles, black racers, cottontail rabbits, grey fox — would probably push farther into the state; wildlife at the southern limit of its range — mink frogs and northern flying squirrels, for example — probably would move north to escape warming temperatures and adjust to shifts in habitat.

"Compared to other parts of the world, global climate change in Maine would lead to a lot more dynamism than other places," said Mac Hunter, a wildlife professor at the University of Maine. "You'd see a lot more species moving in and others moving out here than any random place on the globe."

Some of these shifts may have already begun to happen. A decade or two ago, for example, the red flash of a cardinal's wing was a much rarer site in Maine than it is today.

"Part of that is because of people feeding them," says Ken Elowe, director of the wildlife division at Maine Inland Fisheries and Wildlife, "but part of it has got to be due to some sort of temperature impact that we don't perceive yet."

Possums aren't well-adapted to cold because they have naked tails and ears — some still get frostbite here in the winter — but they also have become a more common resident in Maine in recent years.

Some species might have trouble shifting their geographic range because landscapes are so heavily fragmented by human development now, Hunter said.

"But with that important reservation, the native flora and fauna will fare a whole lot better in the face of global climate change than we will," he said. "It's the human element and all of our support mechanisms in agriculture and forestry and fisheries and these things we've developed to support ourselves that are really threatened."

Indeed, for nature, climate change has always been the norm. Kelley points out that it was extreme climate change that allowed the development of agriculture. But the past 10,000 years have been the most stable climatically in the last million years, he said, and we shouldn't expect that it will last forever.

Especially when humans are tinkering with a climate system that is still largely unknown, Jacobson says. There is now more carbon dioxide in the atmosphere than there has been naturally for at least several million years, he noted.

"And to assume that that will have no consequences is irresponsible, I think," he said.

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