Injecting the right amount of sulfur dioxide into the upper atmosphere could reduce the effects of climate change.

Researchers from University College London in the UK and Harvard University in the USA say adding aerosol particles to thicken the layer of light can reduce climate change caused by greenhouse gases including carbon dioxide.

They used results from a simulation of stratospheric aerosol geoengineering to evaluate whether the approach could offset or worsen the effects of climate change.

Halving warming by adding aerosols to the stratosphere could moderate important climate hazards in almost all regions, while exacerbating the effects in a small fraction of land areas.

Lead author Prof. Peter Irvine of UCL Earth Sciences said that most studies focus on solar geoengineering offsetting all future warming, but while overall climate change can be reduced, it goes too far in many areas.

He said, “If instead only half the warming is offset, then we find that stratospheric aerosol geoengineering could still reduce climate change overall, but would only exacerbate change over 1.3% of the land area.”

The team says solar geoengineering only treats the symptoms of climate change and not the causes, so it should only complement measures to cut emissions.

Irvine added, “Our results suggest that when used at the right dose and alongside reductions in greenhouse gas emissions, stratospheric aerosol geoengineering could be useful for managing the impacts of climate change. However, there are still many uncertainties about the potential effects of stratospheric aerosol geoengineering and more research is needed to know if this idea is truly viable.”

The team are now researching the projected effects of stratospheric aerosol geoengineering on the water cycle to understand the potential benefits and risks to society and ecosystems.