Thank you for this post. I will have to read the articles in Science. But have read your and Mr. Pielke’s blog posts. Given the deplorable policies of the previous, G. W. Bush, administration I am wary of calls for more research (I favor research but I want to to see our emissions growing smaller NOW).

I had the opportunity to speak with some of the people involved with General Motors pilot fuel cell project, and made the point of asking where the hydrogen is coming from. And the answer, of course, was not one that pleased me. There is some advantage on a local scale for places like New York City in terms of air polution, though in terms of cost per vehicle it seems that electric vehicles, hybrids, or internal combustion vehicles burning natural gas would solve the problem of local air polution without spending fedreral research money on a losing game (fuel cells).

What is strange to me is why Mr. Pielke is addressing what he perceives as faults in the IPCC report. Indeed if he were correct in stating that it is going to be exceedingly difficult (more so than is already thought to be the case) to achieve the goal of stabalizing atmospheric CO2 levels (as well as other GHGs) I would think he would be calling for a redoubled effort to build more carbon free energy now. Am I correct in thinking that Mr. Pielke is not already doing so? To me the issue seems quite simple. You build all the carbon free energy (including everything: wind, solar, nuclear, geothermal, hydroelectric) that you can, with a priority towards what is cheapest. While at the same time increasing efficiency, and scaling up CCS to see if it is workable. And most importantly we must close and replace all non CCS coalburning power plants. Which I believe means all of them. If we are going to cut U.S. emissions by 80% from present levels by 2050 we have to be doing so at a rate of 2% per year. If we were to do this by building nuclear power plants we would be talking aproximately 1,600 billion dollars to build the plants. Assuming the same power capacity as the existing 104 plants (20% U.S. electric capacity) and so building 416 plants at 4 billion a pop, and assuming demand remains stable. Demand for power will not get smaller or stabalize without some policy intervention. And thats just America. And I have not even thought about all the none electric power use. Or the rest of the world.

Still it seems do-able.

Who has done work on this subject?

I am stunned to learn you are so touchy about these scenarios. Pielke trashes the scenarios, calls them the source of “Dangerous Assumptions” and you lap it up and strongly defend him. I say a slightly negative thing, (they are “confusing”) and you mock me.

What I was trying to say is “nobody I know has ever really used those scenarios for any serious analysis outside of the IPCC.”

It is entirely possible to study and understand scenarios — and then conclude they are of little practical value.

Given how you have been defending Pielke’s effort to disembowel the scenarios, I can’t understand the above comment.

If the IPCC calls that a baseline scenario, then I suppose it is one more example of why nobody I know has ever really used those scenarios — too many, too confusing.

Your comment is not correct. The Nature article is on all 35 SRES scenarios, many of which are stabilization scenarios, such as B1.

Again, my point is that the IPCC simply did not make any dangerous assumptions (at least not the ones Pielke et al claim). The only dangerous assumption would have been if they assumed stabilization could be achieved without aggressive policies, which is what the Nature article seems to be saying. But, as my excerpts from the report show, that is not the case.

Joe

Your IPCC quote “There is high agreement and much evidence that all stabilisation levels assessed can be achieved by deployment of a portfolio of technologies that are either currently available or expected to be commercialised in coming decades, assuming appropriate and effective incentives are in place for their development, acquisition, deployment and diffusion and addressing related barriers.” is about STABILIZATION scenarios, while PGW are on about BASELINE scenarios.

Richard