Limiting global warming could reduce human risk by 85%

If global warming could be limited to 1.5 degrees Celsius, the risks to humans would be reduced by up to 85 percent. This is the conclusion of a study led by the University of East Anglia (UEA), which also identified hotspot regions for climate change risks.

The researchers investigated how limiting global warming could simultaneously reduce the risk of human exposure to heat stress, water scarcity, coastal and river flooding, and disease. The experts compared the extent of these threats at various levels of warming (1.5°C compared to 2°C or 3.66°C). 

The researchers also measured the impacts of global warming on agricultural yields and the economy. The study shows that overall, human exposure to these risks would be reduced by 10-44 percent if warming is reduced to 1.5°C rather than 2°C. Compared to 3.66 degrees Celsius of warming, a 1.5°C limit would reduce human risks by 32–85 percent.

The threats that were reduced the most were river flooding, drought, and heat stress, but the risk reduction was greatest for drought. Furthermore, West Africa, India and North America were identified as regions where the risks are projected to increase the most by the end of this century.

“Our findings are important because the Paris Agreement target is to limit global warming to ‘well below’ 2°C and to ‘pursue efforts’ to limit it to 1.5°C. This means that decision makers need to understand the benefits of aiming for the lower figure,” said study lead author Professor Rachel Warren.

“In addition, at COP26 last year, the commitments made by countries in terms of greenhouse gas emission reductions are not sufficient to achieve the Paris goals. At present, current policies would result in average warming of 2.7°C, while the Nationally Determined Contributions for 2030 would limit warming to 2.1°C.”

“While there are a number of planned additional actions to reduce emissions further, potentially limiting warming to 1.8°C in the most optimistic case, these still need to be delivered and further additional action is needed to limit warming to 1.5°C.”

The findings are published today in the journal Climatic Change.

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By Chrissy Sexton, Earth.com Staff Writer