Carbon dioxide gets a lot of grief these days. It’s the main cause of the global warming that’s already damaging coral reefs, ice caps, and coastlines. But for eons, life survived on Earth because natural processes kept CO2 levels within limits, preventing the planet from getting either too cold or too hot. So, if we want to keep earth from warming more than a few degrees, we probably need to supercharge those natural processes, in a hurry. Or maybe even invent some new methods to suck carbon out of the sky at an even bigger scale. The question is, can we capture all that carbon before earth becomes too hot for us?