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 Earth didn’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.

Today this approach goes by the slightly less grandiose name of climate engineering, and it is looking more practical. Several recent reviews of these ideas conclude that cooling the planet would be technically feasible and economically affordable.

There are still plenty of skeptics, but even they have started calling for more research into climate engineering. The skeptics understandably fear the unintended consequences of tampering with the planet’s thermostat, but they also fear the possibility  which I’d call a near certainty  that political leaders will not seriously reduce carbon emissions anytime soon.