–Human emissions have so far produced a global average temperature increase of 0.8 degree C.

–There is another 0.6 degree C. to come due to “thermal inertia”, or lags in the system, taking the total long-term global warming induced by human emissions so far to 1.4 degree C.

–If human total emissions continue as they are to 2030 (and don’t increase 60% as projected) this would likely add more than 0.4 degrees C. to the system in the next two decades, taking the long-term effect by 2030 to at least 1.7 degrees C. (A 0.3 degree C. increase is predicted for the period 2004-2014 alone by Smith, Cusack et al, 2007).

–Then add the 0.3 degree C. albedo flip effect from the now imminent loss of the Arctic sea ice, and the rise in the system by 2030 is at least 2 degree. C, assuming very optimistically that emissions don’t increase at all above their present annual rate! When we consider the potential permafrost releases and the effect of carbon sinks losing capacity, we are on the road to a hellish future, nor for what we will do, but WHAT WE HAVE ALREADY DONE.

Any carbon diet strategy would be dependent upon clean coal:

“The vast majority of new power stations in China and India will be coal-fired; not “may be coal-fired”; will be. So developing carbon capture and storage technology is not optional, it is literally of the essence.” –”Breaking the Climate Deadlock,” Tony Blair, June 26, 2008

But:

Vaclav Smil, an energy expert at the University of Manitoba, has estimated that capturing and burying just 10 percent of the carbon dioxide emitted over a year from coal-fire plants at current rates would require moving volumes of compressed carbon dioxide greater than the total annual flow of oil worldwide — a massive undertaking requiring decades and trillions of dollars. “Beware of the scale,” he stressed.”

Dr James Hansen is calling for a moritorium on new dirty coal-fired plants, which is clearly unfeasible from an economic and political perspective. Instead, there is a cheap and simple way to immediately cool down the Earth: just add a little sun dimming aerosol to the upper atmosphere. We won’t be able to stop rapid ecosystem collapse without geoengineering.

“Stabilization of atmospheric greenhouse gases below about 400 ppm of CO2 equivalent is required to keep the global temperature increase likely less than 2C above pre-industrial temperature.” –Report of Working Group 1 of the IPCC, 2007, p. 828

We are currently at 455 ppm CO2 equivalent, and there is new research suggesting that Arctic permafrost is about to melt and emit tremendous amounts of greenhouse gas that will overwhelm any cuts we make to our emissions.

Or maybe we should know more, such as science just now figuring out that glaciers on one lonely mountain behave differently than a polar glacier field. http://www.ippmedia.com/ipp/guardian/2008/08/14/120550.html

I think the main reason it’s important for Hansen to keep highlighting the difference between good science and bad science is that as long as old energy industries sit at the policy table, they’ll be representing and funding bad science. Hansen’s dialectic plays out on the empirical and ecological dimension of this 21st-century movement, and it’s to be expected that most of the net-based discourse about this movement would feature that science bias. Science has been the dominant language of institutional policy since the Enlightenment, only conflicting with religious or cultural policy when it comes to social and behavioral systems like gradeschool curricula and product hazards.

But at the level of the infinite personal decisions and resolutions that have to be made in this movement, the scientific method is powerless. I think this crisis in the public legitimacy of science is evidence that we’re finally beginning to inject values, as a culture, into the territory that science typically dominates, such as climate and the environment. For instance, I’d expect a lot of vague Earth Worship rhetoric from movement leaders who try to get elected to public office, and much more profound appeals to conscience than just slick green marketing schemes for fuel-efficient vehicles.

For example, in Tennessee, there’s been a complete reversal in the orientation of the Christian conservative community to the campaign against mountaintop-removal that was started by environmentalists, students, and rural citizens. The Tennessee Scenic Vistas Protection Act, which would ban mountaintop-removal in the state, has a lobbying effort being led primarily by a Christian environmental group called LEAF (http://www.tnleaf.org/). It’s amazing to see how eco-history has brought evidence-based tree-huggers and faith-based bible-thumpers together for a landmark piece of legislation.

Yes, the solutions must include a wide variety of perspectives, but at the end of the day, the proposed solutions must physically work and not break the bank. Engineering can be an awful help in both activities.