Washington, August 4 : Scientists have suggested that climate change has pushed many animals to the edge, with temperature-induced habitat loss spelling disaster for them.
Scientists have long pointed to physical changes in the Earth and its atmosphere, such as melting polar ice caps, sea level rise and violent storms, as indicators of global climate change.
But changes in climate can wreak havoc in more subtle ways, such as the loss of habitat for plant and animal species.
Climate models project that rising temperatures over time can lead to an increase in dry, desert-like conditions, which will affect not only the survivorship of particular species, but also the natural resources they have adapted to use in their natural environment.
Species are thus forced to move elsewhere to find places to live and food to eat.
"Impacts on individual species indicate wider changes at the biome level that will potentially change conditions for many plant and animal species, in addition to ecosystem services to humans," said Patrick Gonzalez, a researcher at The Nature Conservancy and a member of the Intergovernmental Panel on Climate Change (IPCC).
For example, one species whose habitat may be in danger is the Canada lynx, which is listed as threatened in the United States.
According to Gonzalez, who has worked with USDA Forest Service scientists to analyze lynx habitat, projects that a temperature increase of 2.5 to 4 degrees Celsius in the coming century across the US and Canada, may diminish snow cover suitable for lynx by 10 to 20 percent and reduce boreal forest cover by half in the contiguous US.
Together, these changes could shift lynx habitat northward and decrease the area of habitat in the lower 48 states by two-thirds.
Though climate change can result in animals and plants migrating northward to escape the heat, in many cases, suitable habitat becomes scarce or unavailable farther away from the species' natural range.
As if the direct effects of rising temperatures weren't enough, climate change also has impacts that could make climate patterns less consistent over time.
Michael Notaro, a scientist at the University of Wisconsin-Madison, used climate data from the past century to model vegetation changes over time.
He found that large variability in climate causes an increasing number and intensity of fires and droughts, as well as extreme weather events that could kill long-lived trees and allow short-lived grasses to colonize the leftover space.
His models predict that year-to-year variability in precipitation and temperature reduces the Earth's total vegetation cover, expanding its relative grass cover and diminishing its relative tree cover.
"Climate change threatens to alter extensive areas of habitat," said Gonzalez. "Lynx is one species that is vulnerable, but the potential impacts of climate change on entire ecosystems are even more alarming," he added.