CAN MIGRATING PLANTS MOVE FAST ENOUGH TO AVOID PROJECTED EXTINCTIONS FROM GLOBAL WARMING?

One of the great horror stories associated with predictions of CO2-induced global warming is that the warming will be so fast and furious that many species of plants will not be able to migrate towards cooler regions - poleward in latitude, or upward in elevation - at rates that are rapid enough to avoid extinction. This claim may sound logical enough ... but is it true? 

In a study that goes a long way towards providing a powerful negative answer to this important question, Cowling and Sykes (1999) conducted a review of the literature relative to the interactive effects of concurrent increases in atmospheric CO2 and air temperature on plant growth and development. While doing so, they concluded from what they learned that "increases in CO2 from 350 to 650 ppm are estimated to result in an up to 5°C rise in Topt [plant optimal growth temperature] primarily because of a reduction in rate of photorespiration at high temperatures." And they also observed that "experiments with Phaseolus vulgaris exposed to low CO2 indicate that Topt can decrease by approximately 4°-5°C with a reduction in CO2 from 380 to 200 ppm," citing the work of Cowling and Sage (1998).