Friday September 29, 2023

Satellites link rain, drought intensity to global warming

March 14, 2023

PARIS: The intensity of extreme water cycle events -- especially drought and precipitation or flooding -- correlates strongly with a continuing rise i nd severe droughts and precipitation events in the future.

Earth´s surface has warmed, on average, 1.2 degrees Celsius since the late 19th century, and -- on current policies -- is on track to heat up 2.8C above that benchmark by 2100. By far the largest extreme event of the past 20 years was a sustained deluge over central Africa that “dwarfed” all the others measured.

It caused Lake Victoria to rise by over a metre and was still ongoing in 2021 when the study concluded. “It´s probable that the string of top-ten warmest years (2015-2023) is helping to sustain these ongoing events longer than they would have under more normal global temperature conditions,” said Rodell.

About 70 percent of the events measured lasted six months or less, with an average duration of five to six months. Roughly a third of the top 30 wet and dry events globally occurred in South America. More broadly, the correlations were particularly strong in tropical climates.

The most intense dry event registered happened in the Amazon during the hottest year on record. The research offers concrete support for the IPCC´s most recent assessment report, which found that the severity of extreme water cycle events is increasing.

Extreme droughts and floods are ranked as some of the world´s worst disasters with huge impacts for the economy, agriculture and society. Tropical cyclone Freddy made a loop rarely seen by meteorologists when it returned to hit Mozambique for a second time on Monday, killing at least 70 people in Malawi and Mozambique and displacing thousands.