I hope we can devote some time to that effort next fall. But I am looking forward to your future posts here. One of the most important topics we can be discussing (IMHO, OK maybe not so H).

Keep up the good work.

George

Just look at all the wind map blue from south central Alaska out through the Aleutians. Scaling may not make it obvious but that region is somewhere between 1200-1600 miles long (compared to the Oregon/California blue area that looks to be less than 300 miles long). So if we are looking for the true magic bullet it will be learning how to efficiently and safely transport big time juice long distance without wires, that has to be a least a century farther out than slow fusion. I'm not counting on this policy giving us that kind of time. Seems we may need a lot of fission to manage the 80% reduction in greenhouse emissions by 2050, not to mention a whole new consumption paradigm.

But the Aleutians, near endless black sand beaches, volcanic landscapes-a few degrees global warming and they could be more pleasant than the Hawaiian Islands. Darn, warming could change the wind currents, for a second the future looked so bright.

A little mass transit, population consolidation and team/locale reconfiguration and that footoprint will be reduced--the anti-sport or anti-sport spectacle attitude will never play well to the big audience, though Roman gladiator style sport probably could be done much more sustainably and somewhat reduce the population as well. It certainly deserves serious consideration.

Unfortunately Dr. Pearce does not extend his investigation to the carbon consequences of switching from a uranium based fuel cycle to a thorium based fuel cycle. Thorium can be converted to fissionable U-233 are ratios of 1 to 1 in thermal reactors, and at a higher ratio in Liquid Metal Fast Breeder Reactors. The Indians plan to use a system of LMFBRs and CANDU type heavy water reactors. The indians can mine thorium simply by picking up beach sand in South India, loading it into dump trucks and hauling it to refineries. The EROEI in the Indian Thorium based nuclear system would be very high, no subsurface mining would be required for over a thousand years, and India can have a high energy thorium based economy, that would give the average indian a standard of living similar to that now enjoyed in the United States or Wester Europe.

The LFTR operates even more efficiently than the Indian nuclear system, would produce even less CO2, and no subsurface mining for thorium would be required for several thousand years.

A recent paper is:

"Thermodynamic Limitations to Nuclear Energy Deployment as a Greenhouse Gas Mitigation Technology", International Journal of Nuclear Governance, Economy and Ecology 2(1), pp. 113-130, 2008

The man's either an idiot or a con-man.  Look at the abstract:

Abstract: To both replace fossil-fuel-energy use and meet the future energy demands, nuclear energy production would have to increase by 10.5% per year from 2010 to 2050. This large growth rate creates a cannibalistic effect, where nuclear energy must be used to supply the energy for future nuclear power plants. This study showed that the limit of ore grade to offset greenhouse gas emissions is significantly higher than the purely thermodynamic limit set by energy payback times found in the literature. In addition, any use of nuclear energy directly contributes heat to the Earth, which the Earth must radiate into space by raising its temperature to maintain thermodynamic equilibrium. This is a relatively small effect, but as energy consumption grows it must be considered for a world powered by nucl ear energy. The results of this study demand modesty in claims of `emission-free nuclear energy' as a panacea for global climate destabilisation.

How is it erroneous, misleading and/or fraudulent?  Let me count the ways:

1. To both replace fossil-fuel-energy use and meet the future energy demands, nuclear energy production would have to increase by 10.5% per year from 2010 to 2050. This large growth rate creates a cannibalistic effect, where nuclear energy must be used to supply the energy for future nuclear power plants.

   This is wrong not once, but twice:

   • Nuclear energy provides roughly 8% of total US energy requirements.  To replace all primary energy by 2050, it would have to expand at only 6.3% per year.
   • It would be true for any replacement energy source, and the majority of current plants would be replaced by 2050 anyway.

2. This study showed that the limit of ore grade to offset greenhouse gas emissions is significantly higher than the purely thermodynamic limit set by energy payback times found in the literature.

   We can safely assume that this study uses a once-through LWR cycle, because the USA and perhaps much of the world could run for several centuries on uranium that's already been mined using fast-breeder reactors.  Given that these enormous amounts of uranium were mined for weapons use without making a huge bump in world energy consumption, it's also likely that the projections of energy requirements for mining are unduly pessimistic.

3. In addition, any use of nuclear energy directly contributes heat to the Earth, which the Earth must radiate into space by raising its temperature to maintain thermodynamic equilibrium. This is a relatively small effect, but as energy consumption grows it must be considered for a world powered by nucl ear energy.

   The influence of greenhouse gases from fossil-fuel combustion (1°C today, perhaps 3-5°C to come) utterly swamps the trivial contribution from direct human energy use (~0.01°C).  This is trivially provable via the blackbody equation, and use of this claim by someone who should know better proves beyond all doubt that the intent of the author is to mislead.