Limiting global warming to 1.5 degrees Celsius could save the vast majority of the world’s plant and animal species from climate change, a study has found.
The study, published in the journal Science, shows that limiting warming to the ultimate goal of the Paris Agreement would avoid half the risks associated with warming of two degrees Celsius for plants and animals, and two thirds of the risks for insects.
Species across the globe would benefit, but particularly those in Southern Africa, the Amazon, Europe and Australia, according researchers from the University of East Anglia in the UK.
Reducing the risk to insects is particularly important, the team say, because they are so vital for ‘ecosystem services’ such as pollinating crops and flowers, and being part of the food chain for other birds and animals.
Previous research focused on quantifying the benefits of limiting warming to two degrees Celsius above pre-industrial times – the upper limit for temperature as set out in the Paris Agreement – and did not look at insects.
This is the first study to explore how limiting warming to 1.5 degrees Celsius would benefit species globally.
Researchers, including those at James Cook University in Australia, studied some 115,000 species including 31,000 insects, 8,000 birds, 1,700 mammals, 1,800 reptiles, 1,000 amphibians and 71,000 plants in this, the largest scale study of its kind.
“We measured the risks to biodiversity by counting the number of species projected to lose more than half their geographic range due to climate change,” said Rachel Warren, from UEA.
“We found that achieving the ultimate goal of the Paris Agreement, to limit warming to 1.5 degrees Celsius above pre-industrial levels, would reap enormous benefits for biodiversity – much more so than limiting warming to two degrees Celsius,” Warren said.
“Insects are particularly sensitive to climate change. At two degrees Celsius warming, 18 per cent of the 31,000 insects we studied are projected to lose more than half their range,” she said.
“This is reduced to six per cent at 1.5 degrees Celsius. But even at 1.5 degrees Celsius, some species lose larger proportions of their range,” she said.
“The current global warming trajectory, if countries meet their international pledges to reduce CO2, is around three degrees Celsius. In this case, almost 50 per cent of insects would lose half their range,” she added.
“Other research has already shown that insects are already in decline for other reasons, and this research shows that climate change would really compound the problem,” she said.