On January 1st 2018, postdoctoral researcher Dr. Park Chang-Eui, and associate professor Dr. Sujong Jeong from SUSTech’s School of Environmental Science and Engineering published a new paper on future aridification over the globe in Nature Climate Change entitled ‘Keeping global warming within 1.5ºC constrains emergence of aridification’.

The study indicates that over a quarter of the world’s land could become significantly drier if global warming reaches 2ºC. The change would cause an increased threat of drought and wildfires. But limiting global warming to under 1.5ºC would dramatically reduce the fraction of the Earth’s surface that undergoes such changes.

The findings, published today in Nature Climate Change, are the result of an international collaboration led by the Southern University of Science and Technology (SUSTech) in Shenzhen China and University of East Anglia (UEA).

Aridity is a measure of the dryness of the land surface, obtained from combining precipitation and evaporation. The research team studied projections from 27 global climate models to identify the areas of the world where aridity will substantially change when compared to the year-on-year variations they experience now, as global warming reaches 1.5ºC and 2ºC above pre-industrial levels.

Dr Chang-Eui Park from SUSTech, first author of the study, said: “Aridification is a serious threat because it can critically impact areas such as agriculture, water quality, and biodiversity. It can also lead to more droughts and wildfires - similar to those seen raging across California. “Another way of thinking of the emergence of aridification is a shift to continuous moderate drought conditions, on top of which future year-on-year variability can cause more severe drought. For instance, in such a scenario 15 per cent of semi-arid regions would actually experience conditions similar to ‘arid’ climates today.”

Prof. Su-Jong Jeong from SUSTech, corresponding author of the study, said “The world has already warmed by 1ºC. But by reducing greenhouse gas emissions into the atmosphere in order to keep global warming under 1.5ºC or 2ºC, it could reduce the likelihood of significant aridification emerging in many parts of the world.” Drought severity has been increasing across the Mediterranean, southern Africa, and the eastern coast of Australia over the course of the 20th Century, while semi-arid areas of Mexico, Brazil, southern Africa and Australia have encountered desertification for some time as the world has warmed.

Edited by: Jeremy Welburn