NEW REPORT: Climate change will push wildlife northward and upward.
By JOEL GAY
January 4, 2005
A new national report paints a bleak picture for the wilds of North America if global warming continues, with waterfowl struggling to find wetlands, game animals losing their protective cover and plants possibly unable to pollinate.
In Alaska and northern Canada, where temperatures have risen faster than in most places, the effects could be heightened, according to the report distilled from hundreds of scientific papers by The Wildlife Society, an association of nearly 9,000 wildlife managers, research scientists, biologists and educators, based in Washington, D.C.
"Global warming presents a profound threat to wildlife as we know it in this country," said Douglas Inkley, who chaired the committee that wrote the report.
Among the eight co-authors were representatives from the Institute of Arctic Biology at the University of Alaska Fairbanks, the Marine Biological Laboratory at Woods Hole, Mass., Stanford University's Institute for International Studies, Ducks Unlimited's Institute for Wetland and Waterfowl Research in Canada and the National Wildlife Federation.
The earth's climate is constantly changing, the authors point out. But hundreds of studies in the last 20 years show that human activity has contributed to global warming during the last century.
The effect of rising temperatures has fallen unequally across North America. Nights have warmed more than days, while land surfaces have heated up more than ocean surfaces. Winters have warmed more than summers, the report notes, and temperatures and precipitation in northern latitudes have grown more than in the tropics.
There are too many variables to predict exactly what may happen in the next 100 years, the report says, but models by the leading climate research centers in the United Kingdom, Germany and the United States suggest warming will increase from two to 10 times more in the 21st century than it did in the 20th.
In the broadest terms, researchers believe North American animals and plants will move higher in elevation and farther north as temperatures rise. Some species may benefit from warmer air and water, but the report suggests that others may have a hard time keeping up with the changes.
Animals may find their migratory paths blocked by cities, transportation corridors or farmland. Predators and their prey may not move at the same time, upsetting natural balances. Plants could suffer if the birds and insects that pollinate them head to cooler climes.
Entire forests will migrate over time, the report says. Sugar maples could abandon the northeastern United States, perhaps replaced by the pine and hardwood forests of the southeast. Deer, bears and other animals that inhabit them would move on also.
The changing forest ecosystem could make the forests more susceptible to disease. Rapid warming is thought to have played a role in the spruce bark beetle epidemic that ravaged Southcentral Alaska in the 1990s.
The report notes that the growing season in parts of Alaska lengthened by 20 percent during the last century. In the future, that could mean more wildfires, which can disrupt caribou migration, moose survival and fur-bearer populations for years.
On Alaska's coast, biologists and longtime residents already have seen the effects of thinner sea ice, which is crucial to the survival of walrus, polar bears and some seabird species. For animals already living at the northern edge of North America, there may be no colder places to go.
Bird hunters could see dramatic declines in waterfowl, the report suggests. Wetlands in the Midwest and central Canada are expected to dry up, causing some duck species to decline by as much as 69 percent over the next 75 years. Nesting habitat could be lost as wetlands become more suitable for row crops.
The question before policy-makers and wildlife managers, the report says, is how to soften the impacts of global climate change. The authors suggest that managers adopt a more cautious approach to their work.
Old weather patterns may no longer hold, and extreme events such as 100-year floods could become more common, affecting fish runs and waterfowl habitat. Hunting seasons may have to be revised to account for later rutting periods or declining populations.
The report also suggests that managers maintain healthy populations, which can better withstand a changing climate, and to consider moving affected wildlife populations to guard against extinctions.
The report doesn't call for curbing emissions of greenhouse gases but notes that efforts to improve wildland habitat by planting trees or restoring grasslands and wetlands "has significant potential to offset impacts from global climate change."
Others see the new report as a call to action. After laying out "the full dimensions of global warming's forecast for wildlife," National Wildlife Federation president Larry Schweiger said, "now it is incumbent upon us to change that forecast."