Limiting temperature rise to 1.5oC would avoid 60-95% of climate change impacts, according to new study
Release Date 12 January 2018
The impacts of climate change on the frequency of floods and droughts could be reduced significantly if the global temperature rise can be limited to 1.5oC, and impacts on heatwaves could be almost entirely avoided, says a new report. However, in some regions substantial impacts would remain.
A paper published online in Climatic Change, assesses for the first time some of the global and regional impacts that would be avoided if we met the 1.5o or 2oC targets set out in the Paris Agreement. The study looked at impacts on droughts, river floods, heatwaves and the demands for heating and cooling energy.
Professor Nigel Arnell from the Department of Meteorology at the University of Reading, who led the research with colleagues from the Met Office Hadley Centre and the Climatic Research Unit at the University of East Anglia, said:
“Two years ago, countries reached the Paris Agreement, which commits countries to limit the increase in global temperature to ‘well below’ 2oC and to aim for an increase of no more than 1.5oC. However, there has until now been little evidence on the impacts of climate change that would be avoided if we managed to achieve the 1.5oC target.
"Achieving the target would have the greatest effect on the impacts of extreme heat, which can have severe consequences for human health, labour productivity and crop growth" - Professor Nigel Arnell, University of Reading
“We know that the 1.5oC target is challenging. This research tells us that if we achieve this target then we can avoid between 60 and 95% of the adverse impacts of climate change than we could otherwise see. It also shows that achieving the 1.5oC target results in impacts that would be approximately 25 to 60% lower than if the rise in temperature was allowed to reach 2oC.
“The proportion of the impacts that would be avoided if we achieve the 1.5oC target varies between sectors. Achieving the target would have the greatest effect on the impacts of extreme heat, which can have severe consequences for human health, labour productivity and crop growth. The proportion of impacts that would be avoided also varies between regions, depending on the exposure to impacts in each region and the size and direction of regional changes in rainfall. Even if the 1.5oC target is met, there could still be substantial impacts in some regions.”
Professor Tim Osborn from the University of East Anglia added: “It is well known that the risk of severe impacts from climate change increases with increasing warming: our research has helped put some numbers to these changes. We have incorporated uncertainty in how climate may change and we have considered impacts across 19 regions of the world. Overall, we show there are clear benefits in limiting global warming to 1.5oC, the aim of the Paris Agreement.”
The results also highlight that alongside reductions in emissions, there is a need to plan adaptation measures to deal with the remaining impacts that would not be avoided with a 1.5oC target.
Arnell, N.W., Lowe, J.A., Lloyd-Hughes, B. et al. The impacts avoided with a 1.5 °C climate target: a global and regional assessment. Climatic Change (2017). https://dx.doi.org/10.1007/s10584-017-2115-9