Trying to convince the countries of the world to reduce their carbon emissions is one hell of a coordination problem. It's no surprise that UN climate talks always descend into bickering and in-fighting. But what if we decided to cool the Earth through geo-engineering means instead? True, that would be far from a perfect solution—we probably couldn't stave off most sea level rise, and the oceans would continue to acidify—but mightn't it be easier to get a global deal?
Not necessarily. A new study from climate scientists at the University of Bristol looks at a variety of geoengineering schemes (like shooting sulfate particles into the air to deflect sunlight) and finds that they'd all have widely varying effects on different regions of the Earth:
Their analysis revealed that with increasing geoengineering strength, most regions become drier while others buck the trend and become increasingly wet. For example, the USA became drier with increasing geoengineering, and returned to normal conditions under half-strength geoengineering, whereas Australia became wetter, returning to normal conditions only for full strength geoengineering
Pete Irvine, lead author on the paper, points out there are likely to be disagreements over any future geoengineering schemes: "If there is a large amount of global warming in the future there would be no strength of geoengineering that would be best for everyone: some may be better off without any geoengineering while others may do better with a large amount."
Those UN talks are likely to be just as contentious. Like it or not, there's still no easy answer here.