Suvival notes :

These desperate times call for desperate measures, we must keep the carbon in the atmosphere below 450 ppm according to Dr. Hansen, to avoid the "run away" feedbacks that may make our planet so hot that our descendents will suffer for hundreds of years, and our civilization will be the cause of the worst extinction event since the astroid hit 230 million years ago!

In his latest scientific post : Implications of "peak oil" for atmospheric CO2 and climate by P.A. Kharecha, J.E. Hansen (NASA GISS and Columbia Univ. Earth Institute)our dilema is explained at some length.

The action that we must take is really quite simple : We must work with China and the emerging Asian economies to build Coal fired power plants that sequester the CO2 produced or die.

Simple, yet a profound challenge as until now it has been everyone for themselves and the "market" will sort it out. Since the "market" is an artificial construct, it needs to be changed to fit our current situation, and this can be done if we value both the current environment and our future generations.

THe problem is that there is no real technology that is up to the challenge since we dabble in this vital technology but haven't committed to commercialization of sequestration.

The action needed is to engage with the Chinese as if our lives depend on it ( they do) and immediately begin to produce electric cars for their market, immediately begin to build nuclear power plants on an industrial scale in China to meet their need while we develop the technology for sequestration on a global scale. China won't do this without economic help from the rest of the world, and we must also do this whereever economic growth would attract a new coal fired plant.

The United States should immediately devote a significant resource stream to developing the sequestration techonology and retrofit our many coal plants as a first step, a technology development program, and a leadership act.

Without dealing with the issue of Coal, we risk raising the CO2 beyond the 450 ppm level, and that's a point where the feedback loop will rapidly get out of control.

Hansen and Kharecha don't discuss what happens when the feedback loop goes non-linear but the scenarios we've all seen on the media for global warming understate the reality. Once the co2 gets to a certain ( we don't know precisely where this is) level, then other sources of carbon release kick in like the release of trapped methane hydrates, forest die back, Amazon desert feedback, and the rest. The increase in temprature would be huge, and while the earth may have feedback mechanisms that will compensate, we won't live long enough to find out. The feedback that may balance warming above the 450 ppm level might take the form of an ice age, something that's limited us before. Indeed during the last ice age there may have been only 10,000 humans in Europe and New York may have been covered in a glacier. Either way, it's ugly for civilization and avoidable.

The big message is that if we act now, we can avoid the big desert, the oven. Only if we act together as intellegent beings will we be spared. We don't have to look to the sky for an astroid threatening us, as our threat is already on the horizon and it's only avoidable if we act now.