If you are in favor of the idea, the news that our scientific knowledge of the topic continues to grow will be welcome. But even if you fear humankind lacks the smarts to try intentionally changing our Earth's environment without unintended consequences, new research into a mixologist's approach to the perfect geoengineering strategy should be on your radar.
"investigates for the first time the possibility of using a 'cocktail' of geoengineering tools."
In this study, the scientists mix one geoengineering technique together with another, trying to balance the multiple predicted disturbances caused by the unintentional geoengineering started with the industrial revolution.
For example, increasing the particles in the atmosphere that reflect sunlight should reduce global warming - but it does not reduce the increase in rainfall to the same degree. So the reflective particle method cannot return the climate to its historical steady state because by the time the temperature average is corrected, the rainfall remains above average.
Thinning the cirrus clouds can also reduce warming, by trapping less heat in our atmosphere. But this decreases rainfall too much relative to the amount of global cooling attained.
So a team of scientists from Carnegie as well as the Indian Institute of Science plugged both geoengineering assumptions into their climate models, hoping to see an outcome that returns rainfall and temperature closer to what we have experienced as "normal".
As is so often the case with the best laid plans of men (and women), the models demonstrate that although the outcome works on average, the details often go awry. In the words of Carnegie’s Ken Caldeira,
“The same amount of rain fell around the globe in our models, but it fell in different places, which could create a big mismatch between what our economic infrastructure expects and what it will get. More complicated geoengineering solutions would likely do a bit better, but the best solution is simply to stop adding greenhouse gases to the atmosphere.”
As noted, for the anti-geoengineering crowd, this result should be as welcome as for those who advocate advances in understanding on the subject. It does prove one thing though: if you don't like geoengineering, you should be a fan of the Paris Climate Accord. Not ruining a great thing is definitely preferred over trying to fix it once we break it.