Study: Seeding atmosphere with sulfur dioxide may reduce global warming

Simulations indicate that a layer of aerosol particles applied to the earth's upper atmosphere by aircraft could reduce average global temperatures, at what researchers call a reasonable cost of several billion dollars per year, according to research published today in the journal Environmental Research Letters.

Questions remain, though, regarding region-by-region changes in temperature and water availability, as well as how effective it could be -- researchers say it is just one tool that would need to be used to combat temperature rise on Earth.

The also study suggests that an excess of "solar bioengineering" could have a destructive effect.

"Most studies focus on a scenario where solar geoengineering offsets all future warming," lead author Peter Irvine of London-based UCL Earth Sciences said in a press release. "While this reduces overall climate change substantially, we show that in these simulations, it goes too far in some respects, leading to about 9 percent of the land area experiencing greater climate change."

"However, 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 percent of the land area," he added.

In an attempt to reduce climate change through solar bioengineering, only the symptoms are treated and not the underlying cause of carbon dioxide buildup in the atmosphere, the paper stresses.

The approach explained in the study would only complement other processes to reduce greenhouse gas emissions, researchers say. They warn that the procedure would improve the climate change situation in some places, but worsen it in others by producing more atmospheric moisture.

"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," Irvine added.

The study, which builds on previous research, recommends a goal of reducing global warming by half in using the aerosol method, suggesting that key climate hazards would be substantially reduced.