A rise of just 2 degrees Celsius in global warming could make over a quarter of the world's land to become drier and more desert like, increasing the threat of widespread drought and wildfires, new research led by one of Indian origin has found.
The study showed that reducing greenhouse gas emissions into the atmosphere to limit global warming under 1.5 or 2 degrees Celsius would dramatically reduce the likelihood of significant aridification emerging in many parts of the world, the researchers said.
Aridity is a measure of the dryness of the land surface, obtained from combining precipitation and evaporation.
"Our research predicts that aridification would emerge over about 20-30 per cent of the world's land surface by the time the global mean temperature change reaches 2 degrees Celsius," said Manoj Joshi from the the University of East Anglia's School of Environmental Sciences.
"But two thirds of the affected regions could avoid significant aridification if warming is limited to 1.5 degrees Celsius," Joshi added.
For the findings, published in the journal Nature Climate Change, the team examined 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 and 2 degrees Celsius above pre-industrial levels.
The world has already warmed by one degree Celsius. As a result, 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.
"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," explained Chang-Eui Park from the Southern University of Science and Technology (SUSTech) in China.