Cleaner air ‘threatening’ Amazon

Writing in the journal Nature, the team said they have identified a link between reducing sulphur dioxide emissions from burning coal and increasing sea surface temperatures in the tropical north Atlantic.

The increased temperatures have resulted in a heightened risk of drought in the Amazon, which could dramatically affect the global climate system.

The rainforest contains about one tenth of the total carbon stored in land ecosystems and recycles a large amount of the rainfall that falls upon it.

A team from the University of Exeter, the Centre for Ecology and Hydrology, the Met Office Hadley Centre and the Brazilian National Institute for Space Studies carried out the study.

They estimate that by 2025 a major drought could happen every other year in the Amazon basin, and by 2060, droughts could occur in nine out of every ten years.

Dr Carlos Nobre, from the Brazilian Institute for Space Research, – one of the authors of the Nature article – added: “Global warming, deforestation and increased forest fires are all acting in synergy to reduce the resilience of the Amazonian forests.”

Lead author Professor Peter Cox of the University of Exeter said: “These findings are another reminder of the complex nature of environmental change.

“To improve air quality and safeguard public health, we must continue to reduce aerosol pollution, but our study suggests that this needs to be accompanied by urgent reductions in carbon dioxide emissions to minimize the risk of Amazon forest dieback.”

According to the scientists, sulphate particles from coal-fired power stations have partially reduced global warming by reflecting sunlight and making clouds brighter.

This has mainly been in the northern hemisphere, which has acted to limit warming in the tropical north Atlantic and keeping the Amazon wetter than it would otherwise have been.

Kate Martin