A recent study published in
Nature Climate Change highlights the potentially negative consequences of geoengineering, particularly cloud brightening, on the global climate. This technique aims to reduce temperatures by modifying solar radiation. Specifically, it involves dispersing saltwater into the air to cool the local climate. However, this operation in California could paradoxically intensify heatwaves in Europe.
Illustrative image Pixabay
Researchers from the University of California, San Diego, and the National Center for Atmospheric Research in Boulder, Colorado, used climate models to simulate the impacts of two cloud-brightening operations in the northeastern Pacific Ocean. One was located near California, the other in Alaska. The results show that these interventions, although beneficial in the short term for some regions, could have significant adverse effects on others, notably Europe.
According to 2010 simulations, an operation near Alaska could reduce the risk of extreme heat on the west coast of the United States by 55%. However, projections for 2050 reveal opposite effects. Due to global warming and the slowdown of the Atlantic Meridional Overturning Circulation (AMOC), the operation in Alaska would have a considerably reduced impact, while the one near California could actually increase temperatures.
Jessica Wan, co-author of the study, emphasizes the urgency of developing governance structures for solar geoengineering. "Our study shows that cloud brightening can be very effective for the west coast of the United States if done now, but it could be ineffective in the future and cause heatwaves in Europe," she explains. She urges policymakers to establish guidelines for transparency and regulation, both globally and regionally.
The lack of clear regulation is also highlighted by work conducted in Australia and the United States. Similar cloud-brightening tests have been performed to cool local areas such as the Great Barrier Reef and San Francisco Bay. Without proper regulation, such initiatives could lead to uncoordinated interventions, with potentially harmful global consequences.
The study underscores the importance of a coordinated and transparent approach to geoengineering, a still young and uncertain discipline. In the future, the social and political acceptability of these technologies will depend on their scientific effectiveness as well as their ethical and regulatory framework. Combating climate change requires collaboration between science and policy to avoid conflicting interventions and unforeseen global impacts.
Author of the article: Cédric DEPOND