Lost in the shuffle when you let economists dominate the debate about climate change is the original core value of environmentalism, which is wildlife conservation.
There are is some extreme amount of climate change in which wildlife conservation becomes totally moot, we just give up any economically unused territory to rats and roaches and weeds or jellyfish and slime. Assuming (for the sake of argument, as this is not entirely obvious) that we have the sense not to go that far, what can be conserved and what cannot varies with climate change, biome and species.
Matt Miller at Nature Conservancy has a nice overview of a recent study by Schloss et al of the University of Washington appearing in PNAS, which focused specifically on mammal species. The bottom line is:
Across the Western Hemisphere, on average, 9.2% of mammals at a given location will likely be unable to keep pace with climate change. In some places, up to 39% of mammals may be unable to track shifts in suitable climates. Eighty-seven percent of mammalian species are expected to experience reductions in range size and 20% of these range reductions will likely be due to limited dispersal abilities as opposed to reductions in the area of suitable climate. Because climate change will likely outpace the response capacity of many mammals, mammalian vulnerability to climate change may be more extensive than previously anticipated.