Study Finds Climate Change Makes Heat Waves Longer, Hotter, More Harmful

Washington, Mar 29 AP - A recent study highlights a concerning trend in global climate patterns, revealing that heat waves are not only becoming more frequent but are also moving across the globe at a slower pace, intensifying their impact. Published in Friday's Science Advances, the research indicates a significant shift since 1979, with heat waves now occurring 67% more often and moving 20% more slowly. This change results in prolonged periods of extreme heat over larger areas, affecting more people with higher temperatures than observed four decades ago.

The study, co-authored by climate scientists Wei Zhang of Utah State University and Gabriel Lau of Princeton University, offers a comprehensive analysis focusing on the duration, movement, and intensity of heat waves. Their findings show an alarming increase in the average duration of global heat waves from eight days between 1979 and 1983 to twelve days between 2016 and 2020. Eurasia has experienced particularly severe extensions in heat wave durations, while Africa saw the most significant slowdown in their movement.

North America and Australia are noted for witnessing the largest increases in heat wave magnitude, encompassing both temperature and area covered. "This paper sends a clear warning that climate change is making heat waves more dangerous in multiple ways," commented Michael Wehner, a climate scientist at Lawrence Berkeley National Lab who was not involved in the research.

The study's authors explain that slower-moving heat waves mean prolonged exposure to high temperatures for affected regions, likening it to "an oven" where "the longer the heat lasts, the more something cooks." In this analogy, it is people who are facing the increasing brunt of these intensified conditions. The research utilized computer simulations to trace these changes back to emissions from burning coal, oil, and natural gas, identifying a clear link to climate change.

Additionally, the study delves into alterations in weather patterns that contribute to the propagation of heat waves. It points out that atmospheric waves, including the jet stream which typically moves weather systems along, are weakening. This weakening is part of why heat waves are not being moved along as swiftly as before.

Experts outside of the study have lauded its holistic approach to understanding heat waves. Kathy Jacobs, a climate scientist from the University of Arizona not involved in the study, praised its exploration of how heat waves evolve and move regionally and across continents. Jennifer Francis from Woodwell Climate Research Centre also emphasized the study's importance, stating it underscores "one of the most direct consequences of global warming: increasing heat waves."

This research serves as a stark reminder of the escalating challenges posed by climate change, particularly in terms of human exposure to extreme temperatures. With heat waves becoming longer, slower, and more intense due to human-induced climate change, the findings underscore the urgent need for global efforts to mitigate these impacts.