Climate Scenarios

Climate Scenarios

The researchers based their study on minimum, mid-range, and maximum future climate scenarios based on information released by the United Nation's Intergovernmental Panel on Climate Change (IPCC) in 2001.

According to the IPCC, temperatures are expected to rise from somewhere between 1.5 and more than 4 degrees Fahrenheit (0.8 and more than 2 degrees Celsius) by the year 2050.

"Few climate scientists around the world think that 2050 temperatures will fall outside those bounds," said Thomas. "In some respects, we have been conservative because almost all future climate projections expect more warming and hence more extinction between 2050 and 2100."

In addition, the researchers accounted for the ability of species to disperse or successfully move to a new area, thus preventing climate change-induced extinction. They used two alternatives: one where species couldn't move at all, the other assuming unlimited abilities for movement.

"We are trying to bracket the truth," said Peterson. "If you bracket the truth and look at the two endpoints and they give the same general message, then you can start to believe it."

Outside of the small group of researchers working directly on the impacts of climate change to species diversity, "the numbers will come as a huge shock," said Thomas.