If temperatures rise by 3 degrees Celsius, more than 50% of agricultural land in all six countries would be exposed to severe droughts lasting longer than one year over the 30-year period researchers analyzed, using climate variations from 1961-1990 as a reference.
Even smaller rises in temperatures are projected to have harmful consequences: With a global warming of 2 degrees Celsius, the risk of drought will quadruple in Brazil and China and double in Ethiopia and Ghana, while a 1.5 degrees Celsius rise would triple the probability of drought in Brazil and China.
Global warming not only increases the amount of land exposed to drought but also the length of the weather event, with only a 1.5 degree increase projected to cause droughts lasting longer than two years in Brazil, China, Ethiopia and Ghana, according to Rachel Warren, lead study author and professor with the Tyndall Center for Climate Change Research at the University of East Anglia in England.
Limiting global warming to 1.5 degrees Celsius above pre-industrial levels, as proposed by the Paris Agreement, will “greatly benefit all of the countries in this study, greatly reducing exposure to severe drought for large percentages of the population and in all major land cover classes,” said Jeff Price, study co-author and professor at UEA.
The research suggests “urgent global scale action” is required now “to stop deforestation” and to “decarbonize the energy system in this decade, so that we can reach global net zero greenhouse gas emissions by 2050."
The western U.S. over the past two decades has experienced some of the driest conditions on record. A study from earlier this year found the megadrought in the American Southwest, which began in 2000, led to the driest 22-year period over the past 1,200 years. The extreme conditions have been fueled by human-caused climate change, according to researchers.
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