科學家相信，氣候的改變是導致類似saber-toothed tiger和woolly mammoth等物種消失的原因。
清靜的空氣-涼爽的星球(Clean Air-Cool Planet)的執行長，同時也是這份報告的共同發表人，亞當馬克漢表示，這次物種的移動速度必須比上次的冰河時期還要快十倍。
稍早的研究發現，許多物種早已到全球溫暖化的影響。作者表示，在鳥類方面，例如蘇格蘭的great tit(一種山雀)和亞利桑那的墨西哥橿鳥(Mexican jay，一種鴉科的鳥)都已較早育雛；蝴蝶也搬移了他們的棲地，分布到北歐各地；北極圈的哺乳類，例如北極熊，海象 和北美馴鹿也開始受到海冰減少以及寒原棲地溫暖化的影響。
Imagine a deciduous forest in the Arctic.
Global warming could dramatically alter a third of the world's natural habitat over the next 100 years, according to a study released Wednesday by the World Wide Fund for Nature.
"Global Warming and Terrestrial Biodiversity Decline" is the first attempt to quantify the possible loss of land-based species on a global scale as a result of global warming, said Kara Rinaldi of the World Wide Fund's climate change campaign.
Polar bears are among the most affected by global warming. Studies show diminished body size in many bears.
Previous efforts to model the potential effects of greenhouse warming on global ecosystems focused on flows of energy and matter through ecosystems rather than on species that make up ecosystems.
The problem, the report finds, is that many plant and animal species will not be able to keep up with the modification of their habitat.
"As global warming accelerates, plants and animals will come under increasing pressure to migrate to find suitable habitat," said Jay Malcom, a forestry professor at the University of Toronto and a co-author of the report.
According to the report, the rate of warming is expected to be much faster than the rate of warming that occurred during the most recent ice age 13,000 years ago.
Scientists believe that climate change led to the extinction of such species as the saber-toothed tiger and the woolly mammoth.
"Species will have to move 10 times faster than last time," said Adam Markham, executive director of Clean Air-Cool Planet and a co-author of the report.
In the northern latitudes of Canada, Russia and Scandinavia, where warming is predicted to be most rapid, up to 70 percent of habitat could be lost, the report notes.
In the United States, few regions will be spared, according to the report. More than a third of existing habitats in 11 states - Maine, New Hampshire, Oregon, Colorado, Wyoming, Idaho, Utah, Arizona, Kansas, Oklahoma and Texas - could be changed from what they are today.
"It is likely that sugar maples - a cold-weather species that is characteristic of the Northeast's hardwood forests - will be pushed completely out of New England to Canada," Markham said.
Previous studies found that many species are already affected by global warming. Birds such as the great tit in Scotland and the Mexican jay in Arizona are breeding earlier in the year, the authors note. Butterflies are shifting their ranges to the north throughout Europe, and mammals in many parts of the Arctic, including polar bears, walrus and caribou, are beginning to suffer from the impact of reduced sea ice and warming tundra habitat.
Projections of global warming were based on middle-of-the road estimates by the International Panel on Climate Change, a panel of more than 2,000 scientists who have examined climate change since the early 1990s, the authors note. According to moderate IPCC predictions, the amount of carbon dioxide in the atmosphere will double from pre-industrial levels over the next century. Nevertheless, some scientists suggest a three-fold increase in concentrations by 2100.
The report factors the effect of human influence on the survival of those species able to migrate fast enough to keep pace with rapid warming.
Conditions today make it harder for species to move than ever before, Markham explained. Rare, isolated or slow-moving species could lose out to weeds and pests that can move or adapt quickly.
"The best thing we can do to help wildlife adapt to climate change is to stop destroying their habitat," Markham said. "The more habitat we leave, the more resilient wildlife will be to climate change. The more we mess it up, the more vulnerable wildlife will be."