One in six of the animals and plants on the planet could face extinction if nothing is done to reduce the rate of climate change.
New research suggests species loss is closely linked to climate change – not only increasing but accelerating as temperatures rise.
If global warming continues unabated, raising the Earth’s temperature by 4.3C compared with its pre-industrial level, 16% of species could be at risk.
Certain regions of the Earth are likely to be hardest hit, according to the forecast, with South America, Australia and New Zealand all harbouring vulnerable diverse groups of endemic species with small ranges.
In contrast to the 23% of species affected in South America and 14% in Australia and New Zealand, North America and Europe had the smallest proportion of species facing extinction at 5% and 6% respectively.
The research is based on an analysis of 131 different biodiversity studies taking into account a range of factors including modelling technique, taxonomic group, location, global temperature and species distribution.
Author Dr Mark Urban, from the University of Connecticut in the US, wrote: “The factor that best explained variation in extinction risk was the level of future climate change.
“Global extinction risks increase from 2.8% at present to 5.2% at the international policy target of a 2C post-industrial rise, which most experts believe is no longer achievable.
“If the Earth warms to 3C the extinction risk rises to 8.5%. If we follow our current, business-as-usual trajectory, climate change threatens one in six species (16%).”
Dr Urban pointed out that in 1981 scientists predicted the signal of global climate change would soon emerge from the background “noise” of weather.
He said: “Thirty years later we are reaching a similar threshold for the effects of climate change on biodiversity.
“Extinction risks from climate change are expected not only to increase but to accelerate for every degree rise in global temperatures. The signal of climate change-induced extinctions will become increasingly apparent if we do not act now to limit future climate change.”