The other day John Quiggin suggested that if 160 million tonnes of CO2 are removed from the atmosphere, it will lead to a reduction in temperature (by 2011) of 0.024 degrees celsius.
I asked: “John, I’d like to see your underlying calculations re: “That gives a reduction in equilibrium temperatures of about 0.02 degrees” by 2100 from an annual reduction of 0.00024 degrees. This is a very problematic claim and will require far more (scientific) justification than a short para without clear details.”
In his response to my question John stated: “If you multiply 0.00024 by 100 you get 0.024.”
I think he didn't get my point. I trust he recognises that the assumption behind his claim is that CO2 remains unchanged in the atmosphere forever. Every CO2 molecule in the air remains exactly as it was.
This assumption is incorrect.
A guide published by the Royal Society on 30 September 2010 stated that “even if there was a complete cessation of emissions of CO2 today from human activity, it would take several millennia for CO2 concentrations to return to preindustrial concentrations”. That would seem to support John's view.
But this claim is incorrect.
John, I’d like you to consider two facts:
1. As Dr Klaus Kaiser notes, "If there were no CO2 removal processes, the CO2 concentration in the atmosphere should double every 15 years. But, in fact, over the last 100 years, at most it has increased by only 1/3, i.e. approximately from 300 to 400 ppm (parts per million in weight). The much lower than expected increase (based on fossil fuel consumption) in the atmospheric CO2 can only be explained by a strong (natural) removal process.”
2. Similarly, Dr Ian Plimer who is Australia’s greatest geologist and understands the Earth better than any other, vigorously disputes IPCC claims on this matter. As I’ve noted in a blog post, "the residence time of CO2 in the atmosphere is less than 4 years" (Plimer 413). "There is very little disagreement. The lifetime of CO2 in the atmosphere is about 5 years" (Plimer 422). On the other hand, "The IPCC suggests that the lifetime is 50-200 years. The IPCC lifetime has been criticised because lifetime is not defined and because the IPCC has not factored in numerous known sinks of CO2" (Plimer 421). "If the CO2 atmospheric lifetime were 5 years, then the amount of the total atmospheric CO2 derived from fossil fuel burning would be 1.2%, not the 21% assumed by the IPCC" (Plimer 422). "If humans burnt all the available fossil fuels over the next 300 years, there would be up to 15 turnovers of CO2 between the oceans and the atmosphere and all the additional CO2 would be consumed by ocean life and precipitated as calcium carbonate in sea floor sediments" (Plimer 325).
I’m a strong believer in the big picture test. Detailed estimates must be consistent with back of the envelope analysis.
Claims that half-life of CO2 is over 100 years (or more!) are not borne out by basic common sense.
Therefore, John, you should consider revising your estimates down very significantly, or at least provide a much strong justification (that I'd sought) about why CO2 remains in the atmosphere for ever (despite plants desperately hungering for CO2).
We currently live in an Earth with close to the LEAST amount of CO2 in the atmosphere in its history, since most of it has been sequeseterated into sedimentary rock (animal bones and bacteria contain huge amounts of CO2, which form part of sedimentary rocks).
In the past, with CO2 densities of greater than 15 times current levels, no runaway effects occurred. Many ice ages have had far greater levels of CO2 than found in the current atmosphere.
In brief, John, your estimate needs to be reviewed.
I’m not touching upon the cost-benefit side which is very speculative but clearly there seems to be no significant downside to increased CO2. Only upside. And polar bears have survived with far lower levels of arctic ice cover.
Almost everything (even the cost benefit analysis) depends on whether you think CO2 stays in the atmosphere for ever or is absorbed quickly as part of the carbon cycle.
The complete discussion
- I'm sorry Australia has such a disappointing person on its Climate Change Authority
- Strip Al Gore and IPCC of their Nobel Prize and give it to these people
- If Kevin Rudd continues to abuse those who ask questions, then Australia should bid goodbye to science
- It is not Donna Laframboise but Rajendra Pachauri who is a HUGE liar
- Now John Quiggin says that the world's top scientists are stupid! This is getting absurd.
- John Quiggin, IPCC's peer review process is riddled with holes. I now expect a detailed correction on your blog.
- John, thanks for withdrawing your allegation against Donna's integrity. Here's other stuff you and I should know.
- The total mess that is IPCC. This is very serious stuff. Please do read.
- John (Quiggin), Donna's methodology is totally transparent. Please PROVE she is a liar.
- Now John Quiggin says that Donna Laframboise is lying. I'll ask her about it.
- Second point for John Quiggin: to what extent does IPCC use peer reviewed literature?
- Response to John Quiggin re: longevity of "man-made" CO2 in the atmosphere
- Very important new study that rebuts IPCC generated panic
- Inviting input from readers re: climate change facts, to conduct a debate with John Quiggin
- John Quiggin, I suggest you review your estimate of the impact of Australian CO2 reductions
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