It seems that the Royal Society is looking beyond the optimistic 2 degree goal, and is beginning to analyse possible alternatives. When do we need to talk about 4 degrees? - See the theme issue '
Four degrees and beyond: the potential for a global temperature increase of four degrees and its implications' compiled and edited by Mark G. New, Diana M. Liverman, Richard A. Betts, Kevin L. Anderson and Chris C. West in
Philosophical Transactions of the Royal Society (A; January 2011).
Interesting material, and long overdue.
ReplyDeleteNevertheless I do not like the constant use of A1FI as a scenario, since it is an emission scenario that is, in my opinion, hardly based on a possible reality.
Just looking at the "CO2 from fossil fuels" numbers imply that more coal and oil will be used than is actually there, at least if you believe the predictions of the IEA concerning coal and oil production for the next 30 years.
"imply that more coal and oil will be used than is actually there"
ReplyDeleteAn even larger question is 'economically recover-ability'.
There are absolutely no attempts to determine the points at which economic substitution occurs.
I.E. China currently pays in excess of $100/tonne for imported steam coal. A 1,000 megawatt coal plant requires 3 million tons of coal per year for an annual fuel bill of $300+ million.
A Westinghouse AP1000 nuclear reactor can be built in China for approximately $2 billion.
Standard economics would conclude that barring some strong 'non economic' reason for preferring electricity from coal over electricity from nuclear the substitution will occur in due time.
It's easy enough to conclude that emissions as a result of electricity production will resolve themselves according to the laws of economics.
Transportation is still an issue as the energy density and resulting vehicle range is a substantial argument for not adopting a 'substitute' source of energy.
You say 2 degrees is optimistic but it looks pessimistic to those who have lesser confidence in the predictive capability of climate models. Projecting from observations would suggest 2 degrees is eminently doable under even business as usual scenarios.
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