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James Hansen on Peak CO2 and Big Carbon
Alex Steffen, 21 Apr 08

Jim Hansen with at his clearest and most forceful articulation yet of why climate change, peak oil and human well-being all argue for a massive shift:

Our conclusion is that, if humanity wishes to preserve a planet similar to the one on which civilization developed and to which life on Earth is adapted, CO2 must be reduced from its present 385 ppm (parts per million) to, at most, 350 ppm. We find that peak CO2 can be kept to about 425 ppm, with large estimates for oil and gas reserves, if coal use is phased out by 2030 (except where CO2 is captured and sequestered) and unconventional fossil fuels are not tapped substantially. Peak CO2 can be kept close to 400 ppm, if actual reserves are closer to those estimated by “peakists,” who believe that the globe is already at peak global oil production, having extracted about half of readily extractable oil resources.

This lower 400 ppm peak can be ensured, assuming phase-out of coal emissions by 2030, if a practical limit on reserves is achieved by means of actions that prevent fossil-fuel extraction from public lands, off-shore regions under government control, environmentally pristine regions and extreme environments. The concerned public can influence this matter, but time is short, the industry voice is strong and climate effects have not yet become so obvious to the public as to overwhelm the disinformation from industry moguls.

A near-term moratorium on coal-fired power plants and constraints on oil extraction in extreme environments are essential, because once CO2 is emitted to the air much of it will remain there for centuries. Improved agricultural and forestry practices, mostly reforestation, could draw down atmospheric CO2 about 50 ppm by the end of the century. But a greater drawdown by such more-or-less natural methods seems impractical, making a long-term overshoot of the 350 ppm target level, with potentially disastrous consequences, a near certainty if the world stays on its business-as-usual course.

Yet another place where climate, ecosystems and human well-being all intersect: it's bad for the planet to drill and mine in far-off places, it's bad to burn the oil and coal we get in the process, and the kind of development we get in the bargain is generally bad for most of the people involved.

The case for a bright green economy keeps getting clearer and clearer.

When will we know that the long-term public interest has overcome the greed? When investors, companies and governments begin to invest en masse in renewable energies, when all aim for zero-carbon emissions.

Ultimately the goal is zero.

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Hopefully we are $130M closer to Google's goal of RE < C, renewable power less than the cost of coal. ESolar have just announced another round of financing for their CSP system. Link.

Posted by: JN2 on 21 Apr 08

I have increasing reason to believe that the CO2 ppm numbers that have been bandied around lately will have less meaning and less significance as the potential off-gassing of methane from the newly exposed arctic permafrost becomes noticeably part of the GHG equation. Several sources seem to give a range of methane being a more disruptive GHG than CO2 by a factor that ranges from 10 to 100x (depending on who you listen to). Though currently methane contributes concentrations in the low ppb (parts per billion) - this may change within our current generation.

Further, new coal emitting power plants are being constructed throughout Europe (mainly Italy and Germany) due to the unmanageable costs of oil and nat. gas. Many of these will not easily be convertible to carbon capture units. A shame in a bastion of 'climate change forward thinking' that Europe was once thought to be.

The next 5 - 10 years will certainly be interesting to see where our emissions and technology levels are heading.

Posted by: Jer on 25 Apr 08



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