Existing Aircraft Could Enable Climate Cooling Through Polar Geoengineering, Study Finds

A promising new study suggests that existing large aircraft could be used to deploy climate-cooling particles into the atmosphere, potentially speeding up the implementation of solar geoengineering without the need for specially developed high-altitude planes. Researchers from University College London (UCL) have found that by injecting reflective aerosols at approximately 13 kilometers above the polar regions, meaningful planetary cooling could be achieved.

Until now, most studies have assumed that stratospheric aerosol injection (SAI) would require reaching altitudes near 20 kilometers, mainly over the tropics, necessitating the development of new high-flying aircraft. However, the new research, published in Earth’s Future, suggests that commercial planes like the Boeing 777F, with modifications, could achieve the required polar altitudes.

Lead author Alistair Duffey, a Ph.D. candidate at UCL’s Department of Earth Sciences, emphasized that while solar geoengineering presents considerable risks and demands much more research, their findings show the process could be simpler to initiate than previously thought. "Th

Nevertheless, the study highlights notable drawbacks to the lower-altitude, polar-focused strategy. Cooling effectiveness at 13 kilometers is only about one-third of that achieved at 20 kilometers, meaning that three times as much aerosol would be necessary to reach equivalent temperature reductions. This increase would heighten side effects such as acid rain and would also make the method less effective at cooling tropical regions, where climate vulnerability is greatest.

The research team used the UK’s Earth System Model 1 (UKESM1) to simulate the effects of aerosol injection at various altitudes, latitudes, and seasons. They modeled the release of sulfur dioxide—which transforms into tiny reflective particles—during the spring and summer seasons at around 60 degrees latitude north and south, equivalent to locations like Oslo, Norway, and southern parts of South America.

Because the stratosphere sits closer to the ground at higher latitudes, particles injected there would remain suspended for months, although for shorter periods than if released at equatorial stratospheric heights. In contrast, particles in the lower troposphere would be rapidly washed out by rain.

The simulations estimated that introducing 12 million metric tons of sulfur dioxide annually at 13 kilometers could lower global temperatures by approximately 0.6°C, similar to the cooling effect ob

Although this polar strategy is less efficient, the study notes it could be deployed much sooner. Previous estimates suggest that designing and certifying specialized high-altitude aircraft could take up to a decade and cost several billion dollars. Wake Smith, a co-author and lecturer at Yale School of the Environment, pointed out that while existing planes would still require substantial modifications to serve as aerosol deployment tankers, this approach would be significantly faster than developing new aircraft.

The researchers stress that stratospheric aerosol injection is not a standalone solution. Such interventions would need to be introduced and withdrawn gradually to prevent rapid shifts in global temperatures, and aggressive greenhouse gas reductions would still be necessary for long-term climate stability.

Dr. Matthew Henry of the University of Exeter, another co-author, emphasized, "Stratospheric aerosol injection is certainly not a replacement for emissions cuts, as the potential side effects grow with the degree of cooling achieved. True climate stability can only come with net-zero emissions."

Source:https://phys.org/news/2025-04-geoengineering-technique-cool-planet-aircraft.html

This is non-financial/medical advice and made using AI so could be wrong.