Climate change may have driven the development of human civilisation millenniums ago, but today it may trigger massive species extinction in as little as 100 years, according to Prof Chris Thomas of the University of York.
He presented a bleak view of how our warming climate and rising carbon-dioxide levels will push many species of animal, amphibian and plant to extinction.
Conditions within the coming century will be outside the bounds of those seen on earth for millions of years and never previously experienced by vast numbers of our current species, Prof Thomas told the BA meeting.
"The conditions we expect to see on the planet around the year 2100 are going to be unlike anything we have seen on earth for at least two million and possibly 10 million years."
Estimates suggest that carbon dioxide will reach levels not experienced on earth for the past 24 million years. The impact from that, including acidification of surface waters, will be "huge even aside from climate change".
He said that by 2100 average temperatures are expected to be 5.8 degrees higher than today. "Then we really would be going back to a climate not seen since the age of the dinosaurs."
Species may not be able to evolve quickly enough to cope with the changing conditions. "Something like 10 to 50 per cent of species will be at risk of eventual extinction from climate change."
He said the process may already be under way. Species gravitate away from unacceptable conditions, which, in the context of a warming planet, means they will move north or south depending on the hemisphere where they exist.
"Up to 80 per cent of species are already moving in the directions predicted. This is an incredibly high population of species, given all the other impacts like habitat loss." Climate-triggered fungal outbreaks have already led to the extinction of more than 1 per cent of amphibian species.
