A new study published in Science Advances has cast doubt on a leading theory used to explain the rise in extreme weather events. The resonant Rossby wave mechanism, which scientists have used to explain heatwaves, floods, and droughts, performs poorly when tested against simple climate models.
Theory fails simple test
Researchers Todd A. Mooring and colleagues tested the resonant Rossby wave theory using a simplified climate model. The theory proposes that large atmospheric waves become trapped and amplified under certain conditions, leading to prolonged extreme weather events. But the model results showed the mechanism does not work as predicted.
"The resonant Rossby wave mechanism for extreme weather performs poorly in our simple model test," the researchers wrote. The finding suggests that current understanding of how climate change drives extreme weather may need to be revised.
Extreme weather on the rise
Extreme weather events are becoming more frequent and intense around the world. Record-breaking heatwaves on land and in the ocean, drenching rains, severe droughts, and wildfires have all increased in recent years. The United Nations has warned that the world is almost certain to endure record hot years by 2030.
Human activities, especially the burning of fossil fuels, are driving the changes. Global temperatures have risen about 1.2 degrees Celsius above pre-industrial levels, and every fraction of a degree increases the risk of extreme events.
Implications for climate science
The study highlights gaps in understanding of how atmospheric dynamics connect to extreme weather. Better models are needed to predict when and where extreme events will occur, which is essential for disaster preparation and infrastructure planning. The findings may also affect how scientists communicate climate risks to policymakers and the public.