MORE than a quarter of the world’s land area could become significantly drier if global warming reaches 2°C, causing an increased threat of drought and wild fires.
But an international team of researchers says their findings show limiting the rise to less than 1.5° C would dramatically reduce this.
The work, published in the journal Nature Climate Change, is the result of an international collaboration led by the Southern University of Science and Technology (SUSTech) in Shenzhen China and the UK’s University of East Anglia (UEA).
The 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-to-year variations they experience now, as global warming reaches 1.5°C and 2°C above pre-industrial levels.
SUSTech researcher Chang-Eui Park says aridity measures the dryness of the land surface by combining precipitation and evaporation.
“Aridification is a serious threat because it can critically impact areas such as agriculture, water quality, and biodiversity,” Park says.
“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-to-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.”
UAE Prof Tim Osborn says the world has already warmed by 1°C.
Drought severity increased across the Mediterranean, southern Africa, and the eastern coast of Australia during 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.
“The areas of the world which would most benefit from keeping warming below 1.5°C are parts of Southeast Asia, southern Europe, southern Africa, Central America and southern Australia – where more than 20 per cent of the world’s population live today,” Osborn says.