Topline
As much as the entire population in Brazil, China, Egypt, Ethiopia and Ghana will be exposed to a severe drought lasting more than a year over a 30-year period if global temperatures rise by 3 degrees Celsius, according to a new study, the latest research to warn of life-threatening consequences if humans fail to take intensive actions to mitigate climate change.
Dry cracked earth is visible as water levels are low at Nicasio Reservoir in California.
Key Facts
Researchers involved in the Climate Change study found that as temperatures rise, droughts are expected to become more severe and frequent in all six countries they studied: Brazil, China, Egypt, Ethiopia, Ghana and India, regions chosen because of their diverse sizes, levels of development and climates across three continents.
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,” Warren said.
Surprising Fact
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.
Key Background
Droughts can have an array of damaging effects on human life, the economy, biodiversity and water storage and flows. Droughts can limit crop growth, fueling food shortages and wildfires. Previous research has found that human-induced climate change can increase the probability of droughts and worsen extreme conditions. The U.S. and several other countries experienced severe heat and droughts during the summer of 2022. In Italy, the country’s worst drought in decades caused its largest lake to near its lowest level ever recorded, while countries in the horn of Africa faced the worst drought in 40 years. Global temperatures are expected to increase by anywhere from 1.1 to 5.4 degrees Celsius from current levels by 2100 as carbon dioxide and other greenhouse gases caused by human activity trap heat near Earth’s surface, research has shown. The Paris Agreement, signed by 192 countries and the European Union in 2015, sets forth a goal of limiting global warming to 2 degrees Celsius in this century, and eventually 1.5 degrees compared to pre-industrial levels. The United Nations warned earlier this year countries must act “now or never” and take major actions to limit global warming to 1.5 degrees.
Further Reading
How Bad Is the Western Drought? Worst in 12 Centuries, Study Finds. (New York Times)
Why Are Rivers Drying Up? Global Droughts Are Turning Waterways to Dust (Bloomberg)
Source: https://www.forbes.com/sites/madelinehalpert/2022/09/27/global-warming-will-fuel-more-frequent-severe-and-longer-lasting-droughts-study-finds/