Most of our climate problems could be repaired by cleaning up the excess CO2 in the air and so cooling things off. However, because of abrupt climate flips, the cleanup must be big, quick, and secure. Doubling all forests might satisfy the first two but it would be quite insecure-currently even rain forests are burning and rotting, releasing additional CO2. However, our escape route is not yet closed off. We can still do the equivalent of plowing...