Almost half of plant and animal species have experienced local extinctions due to climate change, research reveals, with the tropics suffering the most pronounced loss

(Pic: Global Water Forum/Flickr)

(Pic: Global Water Forum/Flickr)

Climate change is already beginning to alter the natural world.

A study of 976 plant and animal species worldwide – freshwater, terrestrial and marine – reveals that local extinctions have happened in 47% of their natural ranges.

This does not mean that species have become extinct: the effects are local. Amphibian species that once frequented particular ponds and streams have slipped away, meadow wildflowers have migrated, and once-familiar butterflies and bees have flown favourite nesting places, all in response to global warming.

John Wiens, an ecologist at the University of Arizona at Tucson, reports in the Public Library of Science Biology that he searched the biological databases for studies that recorded the “warm edge” of a species’ habitat: that is, the boundary of the range where conditions start to become too warm for comfort for any particular species.

He may not have expected to see much change, because as a global average the world warmed by just 0.85°C between 1880 and 2012. The forecasts for global warming this century suggest that – unless humans make drastic cuts in fossil fuel consumption – they could rise by another 4°C.

But when Professor Wiens took a closer look at the evidence delivered by studies of 716 animals and 260 plants in Asia, Europe, Madagascar, Oceania and North and South America, he found signs of change in 460 instances, almost half of all studies.

The effect was more pronounced for tropical species, and most pronounced of…