The following quotes are from the IPCC Fourth Assessment, Working Group 1 Report “The Physical Science Basis”, Technical Summary, link:
http://www.ipcc.ch/ pdf/ assessment-report/ ar4/ wg1/ ar4-wg1-ts.pdf

(page 25)
“The concentration of atmospheric CO2 has increased from a pre-industrial value of about 280 ppm to 379 ppm in 2005.”

“Since 1750, it is estimated that about 2/3rds of anthropogenic CO2 emissions have come from fossil fuel burning and about 1/3rd from land use change. About 45% of this CO2 has remained in the atmosphere, while about 30% has been taken up by the oceans and the remainder
has been taken up by the terrestrial biosphere.”

So the rise in atmospheric CO2 from fossil fuel burning was (379 ppm-280 ppm) x 2/3 = 66 ppm.

This number would be in reasonable agreement with your graph only after multiplying the latter by the above-stated ‘airborne fraction’ of 45%:

~160 ppm x 0.45 = ~72 ppm.

So the respectful suggestion is that you might want to mention and clarify the treatment of this airborne fraction in your graph, and perhaps change the graph if this is an issue. This would tidy up your otherwise excellent article in an excellent series of articles.

Thanks again,
Bruce

Thanks for the words of wisdom! I agree with your conclusions and think they are important.

I just have one little query about your bar graph. Is it possible you have left out the fraction of the emitted CO2 that is absorbed by the environment rather than staying in the atmosphere? I believe that is roughly around half of the CO2 at present.

To see this, add up the “Emissions (1751-2006)”, i.e. the black parts of the bars. They seem to add up to something over 200 ppm whereas the known rise in CO2 in that time is around 100 ppm – from ~280 ppm to ~380 ppm.

Thus the bar graph would tend to over-estimate the predicted rise in atmospheric CO2 by, naively, around a factor of 2.

(I also did a quick back-of-the-envelope calculation of the expected CO2 rise from known coal reserves and it seemed to confirm this.)

In reality, the oceans’ uptake of some of the CO2 excess may well saturate when the excess gets large. Also, any feedback mechanisms are left out. So the naive calculation does not illustrate the full potential danger of dumping so much excess CO2 in the atmosphere.

Just to repeat that I appreciate your articles and absolutely agree with your qualitative analysis and conclusions.

Cheers,
Bruce

But CO2 capture by pulverized alkaline earth silicates increases entropy. It occurs spontaneously, and has spontaneously demonstrated itself in mine tailings. It is a winner.

Coal industry CCS seems preposterous to me. The trillion dollar worldwide coal industry can’t come up with one full scale demonstration plant at any level of CO2 removal anywhere in the world so far even with various levels of government assistance. Obviously, they feel that there will be no real threat to the plants they build in the meantime in the way of forced expensive retrofit at their own expense so they are putting them in as fast as they can, and the endless delay and cancellation of the proposed full scale CCS plants is a shell game that will end only with the election of more convinced governments, especially in the US.

Proof of how entrenched these interests feel is Bush’s performance on the last day he was in Japan for the G8 meeting where, once he thought there were no press present and he wouldn’t be reported, he pumped his fist into the air with a big grin saying “goodbye from the world’s biggest polluter” as if he was proud of it, to the shock and dismay of the Prime Minister of the UK and the President of France who were nearby.

Policy discussion ought to include statements that coal plants with no greenhouse gas emission controls built since, say, 1988, or some date in the 1990s, are subject to forced retrofit or closure if they can’t meet whatever minimal standard, say 100% emission reduction, is decided on, because the people building them had to know there would be a price on carbon emissions soon, that they were busy opposing in any way they could all this time.

I’m with Hansen on this point, the fossil fuel industry knew twenty years ago there would come a time, soon if they didn’t do everything they could to oppose it which they did, or later, when greenhouse gas emissions would be taxed. It may well be that Hansen will be testifying at the trials of some of these CEOs when an aroused and enraged human population, at last awake to their peril decides to bring some of the main people responsible for the long delay in taking action to trial.

I don’t follow all this concern about whether it is most important to implement an effective carbon price or that it would be better to stop coal fired power plant construction. Either would take more political will than is available anywhere in the world now, and either could be chosen as part of an overall plan aimed at achieving a stable atmosphere at some reasonable level of greenhouse gas, say 350 ppm equivalent, if sufficient political will were to develop. It isn’t an argument to me that a given level of carbon price has not been effective: jack it up and up and up until it is effective. The theory is sound. If you say there isn’t political will to make it effective but there is enough political will to achieve the same target ppm in some other way I’d say you were smoking something a lot stronger than anything anyone else has on hand.

Bloggers are simply not going to be the ones making the decisions when the time comes: why is it so important for many who educate themselves about climate to take on this task of coming up with a solution that makes sense to them given that no one can predict what technology will be developed by an aroused civilization taking on a threat to its existence or how fast and how many resources will be or can be applied by that civilization at that time? At least we can use very broad stokes when thinking up possible solutions.

Hansen is circulating a paper where he talks about the ideas of an engineer Tom Blees, whose “Prescription for the Planet” is or is about to be published. Hansen says Blees says its possible to build nuclear reactors that run on the high level wastes produced by the past generations of reactors that produce far less waste themselves which decays in shorter time frames. Why store it in Yucca Mountain or anywhere else when you can burn it? More than 95% of the potentially extractable energy is still in the waste, and Blees says almost all of it can be utilized in his proposed design. In any case I think it is a mistake to reject nuclear as if it were worse than global climate change or as if we don’t need anything we can get, or as if the delays in construction caused by a public that does not understand the climate threat will continue once it does. If a nuclear plant can be designed to burn the wastes of the old plants without fear of melting down why not crank them out on an assembly line and put them in as fast as required? A country awake to a threat as great as WWII was to the US could do it.

There is a simple answer, CO2 capture at the source (fossil fuel power plants, cement kilns) imposes a cost on the fossil fuel industry. Air capture is another Treasury raid (as well as silly, work out the energy and materials cost).

In a recent post, Roger lays out some concerns about it, arguing that bio-char may be more cost effective and easy to implement:

http://thebreakthrough.org/ blog/ 2008/ 05/ elements_of_any_successful_app.shtml#more