It's the option climate negotiators here are loath to talk about.
What if they fail to curb global warming and the environment gets so dangerous that someone decides to do something drastic and play mad scientist? Should nations purposely pollute the planet to try to counteract man-made warming and cool the world? Scientists are pretty sure they can do it, but should they?
The issue is called geoengineering purposely tinkering with the planet as opposed to the unintentional warming that's happening now. The most talked about and advanced method involves putting heat-reflecting particles high in the air, but there also have been proposals to seed clouds other ways, put mirrors in space and seed the oceans with iron.
Scientists noticed a temporary but pronounced cooling after the 1991 eruption of Mount Pinatubo in the Philippines. What's in mind would be, essentially, an artificial and constant man-made volcano with material released by aircraft or cannons.
No one is talking about doing it yet. But some scientists want to study it to find about side effects and other issues. And earlier this year, the U.S. National Academy of Sciences said small-scale and controlled experiments could be helpful to inform future decisions.
Even geoengineering's most ardent research supporters aren't proposing it instead of cutting back heat-trapping emissions from burning fossil fuels. But they say someday it may be needed. However, it doesn't solve all climate change problems, just the temperature part.
Stanford University climate scientist Ken Caldeira isn't advocating seeding clouds with sulfur particles any time soon, but he does fear a failure in climate talks and believes that at some point in the future, drastic options will look more palatable. He thinks scientists need to prepare now.
"I think of it as kind of symptomatic relief," Caldeira said in an interview on the sidelines of the U.N.-led Paris talks. "I'm thinking like morphine for the cancer patient." But others inside the negotiations shudder at even talking about the issue.
"The emissions and the climate change that we're causing with that is already a massive experiment on our world that we don't really know the outcome of," said U.N. Assistant Secretary-General Janos Pasztor. "So I don't think we should start another set of experiments and go into geoengineering. I think we should get our act together and reduce our emissions."
Joe Ware, a spokesman for the faith group Christian Aid, was even more blunt.
"It's probably playing God a bit too much for the faith community," Ware said yesterday. He said the world needs more wind farms and solar power instead.
