Portland Press Herald
Tux Turkel
HAMPDEN - It's hardly a tourist attraction, but the Pine Tree Landfill here is certainly Maine's most-visible dump -- a 200-foot mountain of trash sprawling across 42 acres on the edge of Interstate 95.
The thousands of motorists who pass the landfill every day can watch trucks and loaders scurrying across the expanding summit. But it's what they can't see, behind the mound, that's most surprising: A 50-foot high flame, shooting into the sky like a giant cigarette lighter.
Every day, rotting garbage beneath the Pine Tree Landfill gives off enough methane gas to power thousands of homes and provide heat for industry. Now it's just being wasted. Even worse, as the gas wafts into the atmosphere, it acts as a powerful heat trapper that contributes to global climate change.
All that is about to end.
On May 14, the landfill's owners will break ground for Maine's first power plant that converts landfill gas into electricity. When it's operating later this year, the $6 million project will generate enough energy to light roughly 3,000 homes for the next 15 years. It also has the potential, perhaps, to dry lumber or grow vegetables with waste heat from the turbines.
While the 3-megawatt power plant is noteworthy by itself, its larger significance is tied to a second project up the interstate at the state-owned Juniper Ridge Landfill in Old Town. Still in the planning stages, a power project there could light more than 15,000 homes for up to 60 years. It would use engines retired from the Pine Tree Landfill.
"As our gas declines here, we can pull the engines out and use them elsewhere," said Don Meagher, planning and development manager for Casella Waste Systems Inc., which operates both landfills.
What's happening at Hampden and Old Town reflects a national effort to capture the methane from solid waste landfills, to produce home-grown energy and fight global climate change. New tax credits and other financial incentives have made it profitable for Casella and other waste firms to get into the power business.
"Our landfills aren't that large," said David Burns, who monitors landfill gas activity at the Maine Department of Environmental Protection. "There hasn't been enough gas production to make them worthwhile, and the incentives haven't been there. That's all changing."
The United States has at least 2,300 operating or recently closed municipal solid waste landfills. Four hundred have methane power plants, but the U.S. Environmental Protection Agency estimates that 560 additional landfills have the potential to produce enough electricity for 870,000 homes.
At least four other landfills scattered around Maine are candidates to produce energy from methane, Burns said.
These plants also could remove greenhouse gas emissions associated with climate change. Methane is a potent greenhouse gas, 21 times stronger than carbon dioxide. Municipal landfills are the single largest man-made source of the gas, according to the EPA.
To encourage methane power, Congress included production tax credits for landfill gas projects in the Energy Policy Act of 2005. Some New England states that want to encourage renewable power production have put a premium on electricity from landfills. Looking ahead, a pending multi-state agreement to fight global warming is expected to include additional financial incentives for removing greenhouse gases from the atmosphere.
"It has created some revenue to offset expenses," Meagher said.
Casella owns Pine Tree and operates Juniper Ridge for the state. It also owns the Maine Energy trash-to-energy plant in Biddeford and has two landfill gas plants in New York and Vermont.
Maine has closed 300 municipal landfills over the past 25 years; 12 are still operating. Any landfill that accepts household garbage and other organic wastes will generate methane eventually. But to make power production worthwhile, there has to be a large enough output and a system in place to capture the gas.
The Pine Tree Landfill first starting burying waste from the Bangor area in 1975, and now holds 6 million cubic yards. It stopped taking municipal trash in the 1980s, and is set to close by 2010. Most of the disposal now is ash and other residue from the state's waste-to-energy plants, as well as construction and demolition debris.
But tons of household garbage are decomposing in the core, and although the power potential of the landfill has peaked, Casella estimates there's still enough methane for 15 years of electricity generation.
"We're really harvesting energy from the past," Meagher said.
THINKING MODULAR
A recent tour of the landfill shows how the system works.
Sprouting from the mountain are a scattering of plastic pipes and valves. These wellheads are connected to a network of horizontal pipes buried under the landfill. Casella installed the collection system in 2002, not for power, but to control the rotten smell that offended neighbors. The system sucks up gas and pipes it to a central point, where it's burned by a flare inside a chain-link fence. All that remains of the smell -- and the energy -- disappears in a shimmer of flame buffeted by the wind.
Nearby, workers are preparing to set utility poles where the power plant will rise. The plant is designed by Industry and Energy Associates of Portland, which has done similar projects in Delaware and New Jersey. Cianbro Corp. will build it.
Landfill gas generators aren't set up like big power plants. They're more like modular units. Engineers can measure how much methane a landfill is emitting today. They take an educated guess on how much is remaining, based on the age of the facility, how much waste it contains and other factors. Then they plug in a series of one-megawatt engines. Each can be removed as gas output declines.
The Pine Tree Landfill will have three engines. Casella plans to swap them over to Juniper Ridge, if that project goes forward. This arrangement spreads out the company's capital investment. Along with government incentives, engine sharing makes the Pine Tree project economically viable, Meagher said.
At least four other landfills in Maine are candidates for some form of gas power, according to the DEP.
Topping the list is the large Crossroads Landfill in Norridgewock, which also has a gas collection system installed.
In Bath, the DEP is working with the city to reduce odors from hydrogen sulfide gas. In Fort Fairfield, it's involved with the Tri-Community Landfill, which is leaking methane underground. In Augusta, the DEP saw enough power potential at the Hatch Hill Landfill that new boilers at Cony High School were designed to burn landfill gas, Burns said.
"We're really at the beginning of gas-to-energy projects in Maine," Burns said. "It's really hard to say how many will go forward."
Methane power plants have an added benefit. Like all combustion engines, they give off plenty of waste heat. At other landfills, such as the one in Burlington County, N.J., engineers recover the heat to warm greenhouses. The New Jersey operation grows flowers and tomatoes; it even includes a fish farm.
Casella is exploring the economics of a greenhouse, lumber-drying kiln or other ventures at the landfill, Meagher said. That could make Pine Tree Landfill a real tourist attraction some day, a place where tomatoes tossed out 25 years ago are helping to grow the vegetables of tomorrow.
Staff Writer Tux Turkel can be contacted at 791-6462 or:
tturkel@pressherald.com
Monday, April 30, 2007
Ogunquit envisions lure of being 'green town'
Portland Press Herald
By ANNE GLEASON, Staff Writer
Sunday, April 29, 2007
The Meadowmere Resort in Ogunquit displays a flag on its property to let visitors know that the hotel is a Maine Environmental Leader.
To earn its "green" certification, the resort worked with the state to become more environmentally friendly. Its vending machines and arcade games operate using motion sensors. It switched to nonchlorinated cleaner in the swimming pool and installed energy-efficient light bulbs.
A similar state program, which involves earning enough points to receive certification, has been developed for restaurants.
Ogunquit officials are exploring ways to create a similar label for the town. And the benefits of being an official "green town" would be twofold, said Conservation Commission Chairman Mike Horn.
In addition to saving energy and helping the environment, the tourist town could market itself to travelers concerned about the environment and climate change, he said.
"It would be highly advantageous to be able to promote the town as Maine's green town," Horn said. "(Ogunquit's) almost totally a tourist town."
Other communities are going green, through efforts such as the U.S. Mayors Climate Protection Agreement. Portland, Saco and Kennebunk have signed a pledge to reduce carbon dioxide emissions by at least 7 percent below 1990 levels by 2012.
Horn believes Ogunquit could start by encouraging its many hotels and motels to participate in the state's lodging program. The program could then be expanded to restaurants, other businesses and residents who wished to participate to help achieve a townwide green status.
"It's blue sky now, but the more I talk to people, it seems doable," Horn said.
For assistance, the Conservation Commission reached out to Peter Cooke, program manager with the state Department of Environmental Protection's Pollution Prevention Program. Cooke oversees the green-certification programs for lodging and restaurants.
Using existing environmental programs, such as the lodging policy and the Governor's Carbon Challenge, Cooke said a town might be able to develop a communitywide certification program. He said the effort is worth exploring.
"Using a combination of programs to obtain green status as a town there's potential there," he said.
The carbon challenge requires participants to sign a pledge to lower emissions. The state's program has 60 participants. With the exception of about eight to 10 residences, all are businesses, municipalities or nonprofits, Cooke said.
The state program for hotels and motels, launched a year and a half ago through the state DEP's Pollution Prevention program, has 48 participants.
"It's well worth it, not just morally, but it has also made a lot of business sense," said Allyson Cavaretta, director of sales and marketing at the Meadowmere. "I can't stress enough the importance of taking care of the things that people come here to see."
The Inn by the Sea in Cape Elizabeth was among the first to receive certification.
In recent months, the hotel started using biofuel and joined carbonfund.org, allowing guests to donate to the fund to offset carbon dioxide emissions they contributed on their trip by checking a box on their bill, said Rauni Kew, the inn's director of marketing.
Kew said travelers are becoming increasingly aware of environmental issues. A recent TripAdvisor survey found that 38 percent of worldwide travelers see environmentally friendly tourism as a consideration when taking trips.
Also, corporations and businesses that are environmentally conscious have chosen to hold conferences at the hotel because of its efforts and designation, Kew said.
The hotel's environmental practices also have earned Inn by the Sea publicity, including being designated as a top environmental hotel in the Americas by MSNBC. The state, as a whole, could benefit in the same way by getting more entities in line with green initiatives, Kew said.
Vermont and New Hampshire have regional certification programs similar to Maine's lodging and restaurant programs, she said. The Boston Green Tourism initiative encourages hotels and restaurants to go green and promotes Greater Boston as a green destination, according to its Web site.
"It's time to market Maine as a green destination," Kew said. "We are the perfect place to do that, because we are green."
In Bar Harbor, a midcoast tourist town flush with lodging facilities, Graycote Inn owner Roger Samuel said he expects his bed and breakfast's green certification to become increasingly attractive.
"You might find some people who think, 'I can make perhaps a little impact by staying (at a green hotel) as opposed to somewhere else.' It's getting on the radar of more and more people," he said.
The lodging program is based on a points system. Hotels must obtain 100 points to receive certification. After two years, they either have to increase their points to 130 or pay a fee to recertify.
Currently, hotels can earn up to 300 points using various suggestions in the state's workbook, such as switching to geothermal heating or composting food waste.
A similar program is in place for restaurants, and O'Naturals in Portland became the first in the state to receive certification last week, Cooke said.
"This whole green thing's not going away," he said.
Ogunquit resident Bernadine Speers got the Conservation Commission talking about the townwide effort last week.
Speers had heard from a friend about cities in France that "had gone green." The cities, she said, go as far as presenting new residents with a bicycle, implementing green education into school curriculum and banning plastic bags in grocery stores.
Some of those efforts would not work in Ogunquit, but Speers said she finds the concept of a green community intriguing.
Staff Writer Anne Gleason can be contacted at 282-8229 or at:
agleason@pressherald.com
By ANNE GLEASON, Staff Writer
Sunday, April 29, 2007
The Meadowmere Resort in Ogunquit displays a flag on its property to let visitors know that the hotel is a Maine Environmental Leader.
To earn its "green" certification, the resort worked with the state to become more environmentally friendly. Its vending machines and arcade games operate using motion sensors. It switched to nonchlorinated cleaner in the swimming pool and installed energy-efficient light bulbs.
A similar state program, which involves earning enough points to receive certification, has been developed for restaurants.
Ogunquit officials are exploring ways to create a similar label for the town. And the benefits of being an official "green town" would be twofold, said Conservation Commission Chairman Mike Horn.
In addition to saving energy and helping the environment, the tourist town could market itself to travelers concerned about the environment and climate change, he said.
"It would be highly advantageous to be able to promote the town as Maine's green town," Horn said. "(Ogunquit's) almost totally a tourist town."
Other communities are going green, through efforts such as the U.S. Mayors Climate Protection Agreement. Portland, Saco and Kennebunk have signed a pledge to reduce carbon dioxide emissions by at least 7 percent below 1990 levels by 2012.
Horn believes Ogunquit could start by encouraging its many hotels and motels to participate in the state's lodging program. The program could then be expanded to restaurants, other businesses and residents who wished to participate to help achieve a townwide green status.
"It's blue sky now, but the more I talk to people, it seems doable," Horn said.
For assistance, the Conservation Commission reached out to Peter Cooke, program manager with the state Department of Environmental Protection's Pollution Prevention Program. Cooke oversees the green-certification programs for lodging and restaurants.
Using existing environmental programs, such as the lodging policy and the Governor's Carbon Challenge, Cooke said a town might be able to develop a communitywide certification program. He said the effort is worth exploring.
"Using a combination of programs to obtain green status as a town there's potential there," he said.
The carbon challenge requires participants to sign a pledge to lower emissions. The state's program has 60 participants. With the exception of about eight to 10 residences, all are businesses, municipalities or nonprofits, Cooke said.
The state program for hotels and motels, launched a year and a half ago through the state DEP's Pollution Prevention program, has 48 participants.
"It's well worth it, not just morally, but it has also made a lot of business sense," said Allyson Cavaretta, director of sales and marketing at the Meadowmere. "I can't stress enough the importance of taking care of the things that people come here to see."
The Inn by the Sea in Cape Elizabeth was among the first to receive certification.
In recent months, the hotel started using biofuel and joined carbonfund.org, allowing guests to donate to the fund to offset carbon dioxide emissions they contributed on their trip by checking a box on their bill, said Rauni Kew, the inn's director of marketing.
Kew said travelers are becoming increasingly aware of environmental issues. A recent TripAdvisor survey found that 38 percent of worldwide travelers see environmentally friendly tourism as a consideration when taking trips.
Also, corporations and businesses that are environmentally conscious have chosen to hold conferences at the hotel because of its efforts and designation, Kew said.
The hotel's environmental practices also have earned Inn by the Sea publicity, including being designated as a top environmental hotel in the Americas by MSNBC. The state, as a whole, could benefit in the same way by getting more entities in line with green initiatives, Kew said.
Vermont and New Hampshire have regional certification programs similar to Maine's lodging and restaurant programs, she said. The Boston Green Tourism initiative encourages hotels and restaurants to go green and promotes Greater Boston as a green destination, according to its Web site.
"It's time to market Maine as a green destination," Kew said. "We are the perfect place to do that, because we are green."
In Bar Harbor, a midcoast tourist town flush with lodging facilities, Graycote Inn owner Roger Samuel said he expects his bed and breakfast's green certification to become increasingly attractive.
"You might find some people who think, 'I can make perhaps a little impact by staying (at a green hotel) as opposed to somewhere else.' It's getting on the radar of more and more people," he said.
The lodging program is based on a points system. Hotels must obtain 100 points to receive certification. After two years, they either have to increase their points to 130 or pay a fee to recertify.
Currently, hotels can earn up to 300 points using various suggestions in the state's workbook, such as switching to geothermal heating or composting food waste.
A similar program is in place for restaurants, and O'Naturals in Portland became the first in the state to receive certification last week, Cooke said.
"This whole green thing's not going away," he said.
Ogunquit resident Bernadine Speers got the Conservation Commission talking about the townwide effort last week.
Speers had heard from a friend about cities in France that "had gone green." The cities, she said, go as far as presenting new residents with a bicycle, implementing green education into school curriculum and banning plastic bags in grocery stores.
Some of those efforts would not work in Ogunquit, but Speers said she finds the concept of a green community intriguing.
Staff Writer Anne Gleason can be contacted at 282-8229 or at:
agleason@pressherald.com
In mosquito, a small tale of climate change
By Beth Daley, Globe Staff | April 29, 2007
Fourth in a series of occasional articles examining climate change, its effects, and possible solutions.
UNORGANIZED TERRITORIES, Maine -- In a woodsy bog on the road between Millinocket and Baxter State Park, a mosquito that can barely fly is emerging as one of climate change's early winners.
The insect, which lives in the carnivorous purple pitcher plant, is genetically adapting to a warming world. By entering hibernation more than a week later than it did 30 years ago, the Wyeomyia smithii mosquito is evolving to keep pace with the later arrival of New England winters.
Along with Canadian red squirrels and European blackcap birds, the mosquito -- a non biting variety found from Florida to Canada -- is one of only five known species that scientists say have already evolved because of global warming.
The unobtrusive mosquito's story illustrates a sobering consequence of climate change: The species best suited to adapting may not be the ones people want to survive. Scientists say species with short life cycles -- Wyeomyia smithii lives about eight weeks -- can evolve quickly and keep up with changing environmental conditions as a result. Rodents, insects, and birds, some carrying diseases deadly to humans, are genetically programmed to win. Polar bears and whales, which take years to reproduce, are not.
"Rapid climate change is actually now driving the evolution of animals -- that is a dramatic event," said Christina M. Holzapfel, who, with her husband, William E. Bradshaw, has documented genetic changes in hundreds of thousands of mosquitoes at their University of Oregon lab in Eugene. The couple, both evolutionary geneticists, began collecting the mosquitoes at the bog here and in other New England locations more than 30 years ago while at Harvard University.
Until now, the effects of climate warming had been most noticeable in the Arctic, as glaciers melt. But dramatic changes are also being seen in northern temperate zones such as New England, where the average winter temperature has risen 4.4 degrees Fahrenheit over the last 30 years. Growing seasons have lengthened, winter is arriving later, and the weather has become more erratic.
Scientists are worried that climate change, caused largely by the release of heat-trapping gases from power plants and cars, will drive evolution in unpredictable and unwelcome ways in these regions, where millions of people live. Researchers are trying to determine in more detail how species will adapt to a projected 3.2- to 7.2-degree rise in the world's average annual temperature by the end of the century. Their answers could help predict outbreaks of diseases spread by insects and rodents, and how ecosystems will change as species react at different rates to the warming.
"The world is going to be a very different-looking place," said Loren Rieseberg, an evolutionary biologist at the University of British Columbia in Vancouver. He has done rough calculations suggesting that species that take longer than two years to reproduce will not be able to keep up with the current pace of climate change. Some of the laggards will probably become extinct, he said, while others will migrate to new places.
"We are going to have very different sets of organisms living together," he said.
Hibernation in a lab
In a cramped, steamy room at the University of Oregon in Eugene, dozens of mosquitoes feebly flit above rows of red-veined purple pitcher plants. Oversized Petri dishes, each with dozens of mosquito larvae, are stacked nearby.
The windowless room is part of a five-year experiment by Bradshaw and Holzapfel that simulates global warming in Northern Maine. Using sophisticated computers that constantly monitor and adjust the room's temperature and humidity, the couple is replicating the climate of New Jersey -- which northern Maine is expected to experience in 180 years if the current rate of warming continues.
The room's fluorescent lights are programmed to mimic the number of hours of light per day in northern Maine because day length signals mosquitoes to begin hibernating.
In Maine, the mosquitoes mostly begin hibernation on Aug. 25, when there is a little less than 15 hours of daylight. But to survive in New Jersey, they must begin hibernating later in the season, when day length is less than 14 hours, to compensate for the later onset of winter.
Timing of hibernation is a life or death decision for the mosquito: If it begins hibernating too early, it will use up limited nutritional reserves when it doesn't need to and reduce its chance of surviving the winter. If it starts too late, it will freeze to death.
The experiment favors individual mosquitoes in each generation that, because of genetic variation, start hibernating later than the rest of the population. More of these late-hibernating mosquitoes survive the winter and then pass on that later-hibernation genetic trait to the next generation. The process continues until most of the population is hibernating at the best time to ensure they survive the winter.
The experiment, now in its third year, is similar to what is happening in a warming New England, where the growing season is getting longer and winters are arriving later "but the day length stays the same," Holzapfel said.
Survival in a bog
Bradshaw and Holzapfel never set out to study global warming with the fragile Wyeomyia smithii mosquito. As post-graduate students at Harvard in the early 1970s, they became interested in species' biological clocks and settled on the pitcher plant mosquito as a good case study.
The two would pull on hip boots and wade into bogs around Boston and in Northern Maine searching for the stubby plants and their signature tall summer purple blooms.
The plant, which can live 100 years, feeds on ants, moths, and other insects that drown in its water-filled leaves. The mosquito spends much of its life in water and doesn't succumb in the plant's watery trap. The mosquito larvae also feed on the decaying bugs and the adults rarely stray far from the plant: They are so weak-flying, a strong wind will send them crashing to their deaths.
Over the years, Holzapfel and Bradshaw gathered insects and purple pitcher plants from more than 100 sites from Florida to Canada. Back at their lab in Oregon, they would place the mosquitoes in a constant environment and meticulously record at what day length they began hibernating.
As global warming became a pressing scientific issue, the couple pored over their exhaustive records. Their data showed that Millinocket mosquitoes and others at the same latitude (46 degrees north) were starting hibernation 7.5 days later in 1996 than they had in 1972. Bradshaw and Holzapfel demonstrated that this was a genetic response to climate change because the further north they looked, the more mosquito hibernation dates shifted. In Florida, for example, the mosquito hibernation dates didn't change at all.
These observations fit with other scientific evidence that global warming becomes more pronounced closer to the poles.
"No one set out 30 years ago to ask questions about climate warming and evolution," said Bradshaw. "It was a non issue."
'Things are changing'
Nearly every species reacts to changes in the weather. Lilacs bloom earlier if a spring is particularly warm. Mice populations boom in years when winter temperatures are warm enough for them to reproduce.
Yet these responses aren't necessarily genetic: Most species, including humans, have a built-in flexibility -- scientists call it phenotypic plasticity -- that allows them to adjust to temporary environmental conditions. It is partly why we can withstand Boston's frigid winters and steamy summers.
But when the changes are all in the same direction and continue for a long time -- such as the warming taking place in New England -- Charles Darwin's natural selection can take over: Individuals with certain characteristics better suited to the changed environment survive in greater numbers than others in the population. Those individuals then pass on those favorable genetic characteristics to their offspring, eventually leading to evolutionary change in the entire population.
Now that Bradshaw and Holzapfel have demonstrated this shift in the wild among mosquitoes from Maine and elsewhere, they are trying to better understand the exact mechanisms. Their current experiment with Maine day length and New Jersey climate is designed to further illuminate the critical role day length plays in mosquitoes' survival in a warming world.
In the May issue of Genetics, the scientists report that they have identified regions on three chromosomes containing genes involved in controlling mosquitoes' response to day length.
Scientists say that global warming is almost certainly driving evolution of other, less-studied species. And while they know that short-lived species that reproduce rapidly have a better chance of adapting, they cannot yet predict exactly which species will ultimately win and which will face the threat of extinction. Some long-lived species may be able to adjust without genetic changes; humans, for example, can move from flood-prone areas as sea levels rise. Some short-lived species may die because their environment changes too greatly for them to survive.
"The moral of the story is that things are going to be different," said Kevin Emerson, a graduate student in the Bradshaw-Holzapfel lab. "Whether we know exactly what is going to be different . . . I don't think we can say. But people have to accept that things are changing."
Beth Daley can be reached by email at bdaley@globe.com
© Copyright 2007 The New York Times Company
Fourth in a series of occasional articles examining climate change, its effects, and possible solutions.
UNORGANIZED TERRITORIES, Maine -- In a woodsy bog on the road between Millinocket and Baxter State Park, a mosquito that can barely fly is emerging as one of climate change's early winners.
The insect, which lives in the carnivorous purple pitcher plant, is genetically adapting to a warming world. By entering hibernation more than a week later than it did 30 years ago, the Wyeomyia smithii mosquito is evolving to keep pace with the later arrival of New England winters.
Along with Canadian red squirrels and European blackcap birds, the mosquito -- a non biting variety found from Florida to Canada -- is one of only five known species that scientists say have already evolved because of global warming.
The unobtrusive mosquito's story illustrates a sobering consequence of climate change: The species best suited to adapting may not be the ones people want to survive. Scientists say species with short life cycles -- Wyeomyia smithii lives about eight weeks -- can evolve quickly and keep up with changing environmental conditions as a result. Rodents, insects, and birds, some carrying diseases deadly to humans, are genetically programmed to win. Polar bears and whales, which take years to reproduce, are not.
"Rapid climate change is actually now driving the evolution of animals -- that is a dramatic event," said Christina M. Holzapfel, who, with her husband, William E. Bradshaw, has documented genetic changes in hundreds of thousands of mosquitoes at their University of Oregon lab in Eugene. The couple, both evolutionary geneticists, began collecting the mosquitoes at the bog here and in other New England locations more than 30 years ago while at Harvard University.
Until now, the effects of climate warming had been most noticeable in the Arctic, as glaciers melt. But dramatic changes are also being seen in northern temperate zones such as New England, where the average winter temperature has risen 4.4 degrees Fahrenheit over the last 30 years. Growing seasons have lengthened, winter is arriving later, and the weather has become more erratic.
Scientists are worried that climate change, caused largely by the release of heat-trapping gases from power plants and cars, will drive evolution in unpredictable and unwelcome ways in these regions, where millions of people live. Researchers are trying to determine in more detail how species will adapt to a projected 3.2- to 7.2-degree rise in the world's average annual temperature by the end of the century. Their answers could help predict outbreaks of diseases spread by insects and rodents, and how ecosystems will change as species react at different rates to the warming.
"The world is going to be a very different-looking place," said Loren Rieseberg, an evolutionary biologist at the University of British Columbia in Vancouver. He has done rough calculations suggesting that species that take longer than two years to reproduce will not be able to keep up with the current pace of climate change. Some of the laggards will probably become extinct, he said, while others will migrate to new places.
"We are going to have very different sets of organisms living together," he said.
Hibernation in a lab
In a cramped, steamy room at the University of Oregon in Eugene, dozens of mosquitoes feebly flit above rows of red-veined purple pitcher plants. Oversized Petri dishes, each with dozens of mosquito larvae, are stacked nearby.
The windowless room is part of a five-year experiment by Bradshaw and Holzapfel that simulates global warming in Northern Maine. Using sophisticated computers that constantly monitor and adjust the room's temperature and humidity, the couple is replicating the climate of New Jersey -- which northern Maine is expected to experience in 180 years if the current rate of warming continues.
The room's fluorescent lights are programmed to mimic the number of hours of light per day in northern Maine because day length signals mosquitoes to begin hibernating.
In Maine, the mosquitoes mostly begin hibernation on Aug. 25, when there is a little less than 15 hours of daylight. But to survive in New Jersey, they must begin hibernating later in the season, when day length is less than 14 hours, to compensate for the later onset of winter.
Timing of hibernation is a life or death decision for the mosquito: If it begins hibernating too early, it will use up limited nutritional reserves when it doesn't need to and reduce its chance of surviving the winter. If it starts too late, it will freeze to death.
The experiment favors individual mosquitoes in each generation that, because of genetic variation, start hibernating later than the rest of the population. More of these late-hibernating mosquitoes survive the winter and then pass on that later-hibernation genetic trait to the next generation. The process continues until most of the population is hibernating at the best time to ensure they survive the winter.
The experiment, now in its third year, is similar to what is happening in a warming New England, where the growing season is getting longer and winters are arriving later "but the day length stays the same," Holzapfel said.
Survival in a bog
Bradshaw and Holzapfel never set out to study global warming with the fragile Wyeomyia smithii mosquito. As post-graduate students at Harvard in the early 1970s, they became interested in species' biological clocks and settled on the pitcher plant mosquito as a good case study.
The two would pull on hip boots and wade into bogs around Boston and in Northern Maine searching for the stubby plants and their signature tall summer purple blooms.
The plant, which can live 100 years, feeds on ants, moths, and other insects that drown in its water-filled leaves. The mosquito spends much of its life in water and doesn't succumb in the plant's watery trap. The mosquito larvae also feed on the decaying bugs and the adults rarely stray far from the plant: They are so weak-flying, a strong wind will send them crashing to their deaths.
Over the years, Holzapfel and Bradshaw gathered insects and purple pitcher plants from more than 100 sites from Florida to Canada. Back at their lab in Oregon, they would place the mosquitoes in a constant environment and meticulously record at what day length they began hibernating.
As global warming became a pressing scientific issue, the couple pored over their exhaustive records. Their data showed that Millinocket mosquitoes and others at the same latitude (46 degrees north) were starting hibernation 7.5 days later in 1996 than they had in 1972. Bradshaw and Holzapfel demonstrated that this was a genetic response to climate change because the further north they looked, the more mosquito hibernation dates shifted. In Florida, for example, the mosquito hibernation dates didn't change at all.
These observations fit with other scientific evidence that global warming becomes more pronounced closer to the poles.
"No one set out 30 years ago to ask questions about climate warming and evolution," said Bradshaw. "It was a non issue."
'Things are changing'
Nearly every species reacts to changes in the weather. Lilacs bloom earlier if a spring is particularly warm. Mice populations boom in years when winter temperatures are warm enough for them to reproduce.
Yet these responses aren't necessarily genetic: Most species, including humans, have a built-in flexibility -- scientists call it phenotypic plasticity -- that allows them to adjust to temporary environmental conditions. It is partly why we can withstand Boston's frigid winters and steamy summers.
But when the changes are all in the same direction and continue for a long time -- such as the warming taking place in New England -- Charles Darwin's natural selection can take over: Individuals with certain characteristics better suited to the changed environment survive in greater numbers than others in the population. Those individuals then pass on those favorable genetic characteristics to their offspring, eventually leading to evolutionary change in the entire population.
Now that Bradshaw and Holzapfel have demonstrated this shift in the wild among mosquitoes from Maine and elsewhere, they are trying to better understand the exact mechanisms. Their current experiment with Maine day length and New Jersey climate is designed to further illuminate the critical role day length plays in mosquitoes' survival in a warming world.
In the May issue of Genetics, the scientists report that they have identified regions on three chromosomes containing genes involved in controlling mosquitoes' response to day length.
Scientists say that global warming is almost certainly driving evolution of other, less-studied species. And while they know that short-lived species that reproduce rapidly have a better chance of adapting, they cannot yet predict exactly which species will ultimately win and which will face the threat of extinction. Some long-lived species may be able to adjust without genetic changes; humans, for example, can move from flood-prone areas as sea levels rise. Some short-lived species may die because their environment changes too greatly for them to survive.
"The moral of the story is that things are going to be different," said Kevin Emerson, a graduate student in the Bradshaw-Holzapfel lab. "Whether we know exactly what is going to be different . . . I don't think we can say. But people have to accept that things are changing."
Beth Daley can be reached by email at bdaley@globe.com
© Copyright 2007 The New York Times Company
Earth Portal
I was just made aware of a new web site which is a portal to articles concerning the environment. More specifically and according to the site, the "Earth Portal is a comprehensive resource for timely, objective, science-based information about the environment. It is a means for the global scientific community to come together to produce the first free, expert-driven, massively scaleable information resource on the environment, and to engage civil society in a public dialogue on the role of environmental issues in human affairs. It contains no commercial advertising and reaches a large global audience."
The URL for the site is as follows:
Earth Portal Web Site
The URL for the site is as follows:
Earth Portal Web Site
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