5 Dec 2011. Climate Changes Faster Than Species Can Adapt, Rattlesnake Study Finds. ScienceDaily.

The ranges of species will have to change dramatically as a result of climate change between now and 2100 because the climate will change more than 100 times faster than the rate at which species can adapt, according to a study In PLoS ONE by A. Michelle Lawing, et.al.
“We find that, over the next 90 years, AT BEST (note 1) these species’ ranges will change more than 100 times faster than they have during the past 320,000 years. This rate of change is unlike anything these species have experienced, probably since their formation.”
Rattlesnake ranges have moved an average of only 7 feet a year over the past 320,000 years.   Their tolerance to climate has evolved 100 to 1000 times slower, so range shifts are the only way rattlesnakes can adapt to climate change. Over the next 90 years, the ranges will be displaced by a remarkable .25 mile to 1.5 miles a year.
note 1 (my comment): The 2007 IPCC projections were too conservative, their worst-case projections have already been exceeded