Climate change has a very high procrastination penalty that just grows with each passing year of inaction - rather like what happens if you don't pay off your credit card. But for climate, there is no such thing as a fresh start from bankruptcy.

It's going to be like herding stray cats, and the political leaders who can do it will be remembered as the same kind of geniuses who pulled off the American Revolution.

The real focus needs to be on political action to stop this runaway train, real soon.

Our CO2 mixes with everyone else's within a year, then hangs around for centuries like a shroud.

Carbon-free energy is simply something we have to do. The time for talk is past. If we turn around net carbon emissions by 2020 rather than 2040, we get another 2° of fever rather than 3° - and that's a big difference.

Countries that innovate first get the new jobs, developing an economic edge over the C-free laggards that end up having to later import the technology.

Even if we stop the growth, we'd still be adding a constant amount of fossil carbon to the atmosphere each year.