Germana Carillo The goal of climate engineering would be to try to avoid the worst consequences of climate change, but a new study demonstrates for the first time the reduction and even reversal of the benefits of a cloud-clearing strategy as climate conditions change
New techniques for cloud modification used to cool the climate in California could potentially push heatwaves towards Europe. If global warming reaches 3.6°F (2°C) above pre-industrial levels by 2050, the scientific alteration of clouds could further warm almost all of Europe, except the Iberian Peninsula.
A research team from the University of California, San Diego, revealed in a new study that temperatures could rise more in Scandinavia, Central Europe, and Eastern Europe. They concluded that if the planet continues to warm at the current rate, this geoengineering strategy might not only stop working but could also start having completely opposite effects.
Alarming results due to lack of regulation
These results are particularly concerning because there is currently almost no regulation in place for this type of local climate modification, making the consequences difficult to predict.
“Our study provides the first evidence that regional climate interventions, which today seem promising for managing climate risk, could become ineffective as the climate continues to change,” explains Kate Ricke, co-author of the study.
Marine cloud brightening technique and the study
The technique, known as Marine Cloud Brightening (MCB), involves injecting sea salt particles into the atmosphere to make clouds brighter and more reflective. The principle is simple: more reflected light means less heat absorbed by the Earth.
However, the new study simulated the large-scale application of MCB in the North Pacific, showing up to a 55% reduction in the risk of heatwaves in parts of the western United States. But this comes with significant downsides, including drastic reductions in precipitation not only in the U.S. but also in remote regions like Africa’s Sahel, and extreme heatwaves in Europe.
“The warming we derive from mathematical models is particularly high in Scandinavia, Central, and Eastern Europe,” explains Katharine Ricke. “Surprisingly, this could even end up increasing risk due to the complexity of the climate system, which we do not fully understand.”
In practice, scientists used climate simulations from 2010 and projections for 2050. By comparing these, they showed the impact an MCB project to cool the western United States could have on the rest of the globe.
Impact on global precipitation and heatwaves
The study used two locations in the North Pacific: one in a temperate region near Alaska and another in a subtropical region near California. Both aimed to reduce the risk of extreme heat on the U.S. west coast. Under current climate conditions, they found that MCB reduces the risk of extreme summer heat in some parts of the western U.S. by up to 55%. However, it drastically reduced precipitation in this region and other parts of the world like the Sahel in Africa.
The study’s authors conclude that this could result from the slowdown of the Atlantic Meridional Overturning Circulation (AMOC), a global ocean conveyor belt that circulates water from north to south and back in a long cycle within the Atlantic Ocean.
Conclusion: the effectiveness of artificial climate controls
In short, artificial climate controls could become ineffective due to climate change. So, should we rely on geoengineering or not?
