Kind of like stopping a volcano or an earthquake. What happens when the problem gets too far gone and the vaunted human ingenuity is utterly impotent in solving the problem? (I mean the point after which there is literally nothing humans could do to react to the problem.)

To get an idea of the monumental complexities of global warming, I recommend reading The Emerald Planet: How Plants Changed Earth's History by David Beerling. He describes a multi-discipline investigation of global warming involving paleobotanists to atmospheric scientists, climate scientists, oceanographers, chemists, physicists, and the list goes on.

I also recommend googling "planetary boundaries" and "tipping points". Climate change is only one of the boundaries whose transgression threatens us. And the boundaries interact with each other and we don't really know how these interactions might affect rates of change.

So, radical changes now -- bad. Human ingenuity and radical changes in the future on the threshold of global catastrophe -- good.