Regional Biodiversity in a Warmer World

CO2 Science

NASA's James Hansen claims that as temperatures around the world continue to rise, "polar species can be pushed off the planet, as they have no place else to go," and that life in alpine regions "is similarly in danger of being pushed off the planet," while England's Sir John Houghton declares that "we are in danger of losing thousands, if not millions, of species because of climate change."

These ominous words of warning, which portend significantly reduced species richness over much of the earth in future years -- if the planet continues to warm -- sound logical enough, but are they true?

We have long argued that these contentions are false, since in a CO2-accreting atmosphere -- such as we are destined to have for some time to come -- most plants prefer warmer temperatures, so that while warming gives them the opportunity to move poleward in latitude and upward in altitude at the cold-limiting boundaries of their ranges, it does not mandate that at the heat-limiting boundaries of their ranges they must move in these directions. Hence, with the greater over-lapping of vegetative species ranges that these phenomena portend for concomitant increases in atmospheric temperature and CO2 concentration, there should be a tendency for regional plant species richness to actually increase over the world; and it is our belief that this same type of range overlapping will apply to many of the world's animals that rely on these plants for their food and habitat.