The report's findings echo those of a 2004 study, in which a team of international scientists suggested that over a million species15 to 35 percent of those they studiedcould be at risk of extinction by 2050.
Both the 2004 study and the current research were conducted in part by scientists from Conservation International.
"We used a completely different set of methods [from the 2004 study] and came up with similar results," Conservation International's Lee Hannah, co-author of the current study, told Reuters.
"All the evidence shows that there is a very serious problem."
Hot Spot Species Live on the Edge
Stuart Pimm, an expert in extinctions and biodiversity at Duke University in Durham, North Carolina, explained that species living in ecological hot spots are at particular risk when their environments change.
"That's where the most vulnerable species are, because they have the smallest geographical ranges," said Pimm, who is not affiliated with the study.
Species living high on tropical mountainsides, for example, have nowhere to go if temperatures warm their home turf.
In South Africa's Cape Floristic Region, located on the continent's southern tip, species are unable to migrate to lower latitudes to escape the rising temperatures.
"There's no question that the poles are experiencing the greatest climatic change," Pimm said.
But polar species are far fewer in number and may not face the same extinction risk as those that live in more confined hot spots with greater biodiversity.
"While polar bears and caribou are being harmed, they are not as vulnerable as the species that live in these hot spots because of [the hot spot species'] very narrow geographic ranges."
Other experts warn that it's not just the hot spots featured in the new study that face an imminent extinction risk.
"Many species are indeed struggling to hold on in locations all over the globe, not just in hot spots," said biologist Terry Root, of Stanford University's Center for Environmental Science and Policy, who was not involved in the study.
"This is not some activity that will only be occurring 'overseas.' The likely extirpations and extinctions will also be occurring within a couple hundred miles of all of our back yards."
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