https://www.nytimes.com/2009/08/11/science/11tier.html?_r=2&hpw
President Obama and the rest of the Group of 8 leaders decreed last month that the planet’s average temperature shall not rise more than 2 degrees Fahrenheit above today’s level. But what if Mother Earthdidn’t get the memo? How do we stay cool in the future? Two options:
Plan A. Keep talking about the weather. This has been the preferred approach for the past two decades in Western Europe, where leaders like to promise one another that they will keep the globe cool by drastically reducing carbon emissions. Then, when their countries’ emissions keep rising anyway, they convene to make new promises and swear that they really, really mean it this time.
Plan B. Do something about the weather. Originally called geoengineering, this approach used to be dismissed as science fiction fantasies: cooling the planet with sun-blocking particles or shades; tinkering with clouds to make them more reflective; removing vast quantities of carbon from the atmosphere.