This new study is very bad news for the Global South, and bad news for the rest of us too. The climate is changing much faster than we had previously understood. Changes that had been expected in the 2080s are being observed in the Southern Hemisphere now.
by Weizmann Institute of Science
A new study, published today in Nature Climate Change, will certainly make the IPCC—and other environmental bodies—take notice. A team of scientists led by Dr. Rei Chemke of Weizmann's Earth and Planetary Sciences Department revealed a considerable intensification of winter storms in the Southern Hemisphere. The study, conducted in collaboration with Dr. Yi Ming of Princeton University and Dr. Janni Yuval of MIT, is sure to make waves in the climate conversation. Until now, climate models have projected a human-caused intensification of winter storms only toward the end of this century. In the new study, Chemke and his team compared climate model simulations with current storm observations. Their discovery was bleak: It became clear that storm intensification over recent decades has already reached levels projected to occur in the year 2080.
"A winter storm is a weather phenomenon that lasts only a few days. Individually, each storm doesn't carry much climatic weight. However, the long-term effect of winter storms becomes evident when assessing cumulative data collected over long periods of time," Chemke explains. Cumulatively, these storms have a significant impact, affecting the transfer of heat, moisture and momentum within the atmosphere, which consequently affects the various climate zones on Earth. "One example of this is the role the storms play in regulating the temperature at the Earth's poles. Winter storms are responsible for the majority of the heat transport away from tropical regions toward the poles. Without their contribution, the average pole temperatures would be about 30°C lower." Similarly, the collective intensification of these storms yields a real and significant threat to societies in the Southern Hemisphere in the next decades.
"We chose to focus on the Southern Hemisphere because the intensification registered there has been stronger than in the Northern Hemisphere," Chemke says. "We didn't examine the Northern Hemisphere, but it seems that the intensification of storms in this hemisphere is slower compared to that in the Southern Hemisphere. If the trend persists," Chemke adds, "we will be observing more significant winter storm intensification here in the upcoming years and decades."
More powerful winter storms don’t necessarily mean more precipitation. Brazil, Argentina, Paraguay and Chile are in a multi year drought.
By John Bartlett in Pintué
Unprecedented drought makes water a national security issue as more than half of Chile’s 19 million population lived in area with ‘severe water scarcity’ by end of 2021
From the Atacama Desert to Patagonia, a 13-year megadrought is straining Chile’s freshwater resources to breaking point.
By the end of 2021, the fourth driest year on record, more than half of Chile’s 19 million population lived in an area suffering from “severe water scarcity”, and in April an unprecedented water rationing plan was announced for the capital, Santiago.
In hundreds of rural communities in the centre and north of the country, Chileans are forced to rely on emergency tankers to deliver drinking water.
“Water has become a national security issue – it’s that serious,” said Pablo García-Chevesich, a Chilean hydrologist working at the University of Arizona. “It’s the biggest problem facing the country economically, socially and environmentally. If we don’t solve this, then water will be the cause of the next uprising.”