Anthony Watts today posted an article on his blog rejecting chemistry, biology and photosynthesis (archived here). The article was written by WUWT "guest" essayist, James McCown, who wrote:
...if the CO2 concentration is accurately measured by Etheridge et al (1996), then it is more likely the result of a natural process than from industrial sources.James McCown is said to be an "economist with the Toltec Group, an economic consulting practice in Oklahoma and has a PhD in economics from Ohio State." It looks as if he is the Toltec Group. I'd say he is the sum total of the Toltec Group, which from its website is mainly interested in oil and gas (and flogging a free android app). I'd not recommend commissioning him to do any research relating to climate (or economics).
Most scientists will agree that most of the CO2 concentration changes of the past 1000 years as reported by Etheridge et al way back in 1996 would have been the result of natural processes rather than from industrial sources. The main contribution from industrial sources would have been from the industrial era, since the 1700s. Most of the changes from the several centuries prior to that would have been from natural sources, with only small changes arising from human activities such as deforestation and agriculture. So that's nothing new.
However I don't think that's what James McCown meant. I believe he was trying to argue that plants don't use CO2 in photosynthesis and that burning fossil fuels doesn't release carbon dioxide. It seems to me that he's rejecting plant biochemistry (photosynthesis) as well as chemistry (the reaction of burning hydrocarbons). What he seems to be saying is that the recent hike in atmospheric CO2 wasn't added by humans.
I put together a chart based on these data from Lüthi et al 2009, just averaging the CO2 over each 10,000 years of the past 800,000 years and adding what's happened in the past 150 years, since we've been burning up fossil fuels and chopping down trees at a greater pace than ever:
|Data source: Lüthi et al (2008)|
Atmospheric CO2 oscillated between around 180 ppm and 280 ppm over the past 800,000 years as Earth cooled and warmed. It's only in recent decades that it's gone above 300 ppm and has now shot up to 400 ppm. Burning gigantic amounts of fossil fuels is the main reason for this. James hasn't thought it through when he writes: "it is more likely the result of a natural process than from industrial sources". In fact he doesn't even indicate what "natural process" could possibly cause such a stupendously huge amount of CO2 to get into the air all of a sudden.
Most of the WUWT article was about a paper and a comment on the paper. The first paper was by Michael Beenstock and colleagues, published in November 2012. It was one of those statistical analyses that pop up from time to time wherein deniers try to prove that AGW doesn't exist or is minimal. The paper looks to have been an "it's the sun" claim, with the opening para in the Discussion section being (my bold):
We have shown that anthropogenic forcings do not polynomially cointegrate with global temperature and solar irradiance. Therefore, data for 1880–2007 do not support the anthropogenic interpretation of global warming during this period. This key result is shown graphically in Fig. 3 where the vertical axis measures the component of global temperature that is unexplained by solar irradiance according to our estimates. In panel a the horizontal axis measures the anomaly in the anthropogenic trend when the latter is derived from forcings of carbon dioxide, methane and nitrous oxide. In panel b the horizontal axis measures this anthropogenic anomaly when apart from these greenhouse gas forcings, it includes tropospheric aerosols and black carbon. Panels a and b both show that there is no relationship between temperature and the anthropogenic anomaly, once the warming effect of solar irradiance is taken into consideration.
The Beenstock paper is pretty well all statistics and econometrics which is beyond my expertise. It wasn't based on climate science. It didn't get much attention, being cited only 14 times so far (according to Google Scholar), with most citations being either refutations mixed with the occasional citation from other science deniers (eg Willie Soon). At WUWT James is trying to defend the paper against one of the papers that pointed out its flaws, by Pretis and Hendry - who took it on from an econometric perspective. A fight fire with fire approach.
Michael Beenstock has only tackled global warming in one other paper that I found, and that was about tide gauges. I gather he's a climate science denier whose own field isn't climate science but economics.
The comment on the paper was by two economists, F. Pretis and D. F. Hendry, who argued there were errors in the Beenstock paper, which they discuss under six main headings. Anyway, that's enough of that. This HW article isn't about the merits or otherwise of the different papers. The papers themselves rely on technical analysis which is beyond my expertise and they aren't really about climate science, they are about statistics/econometrics. I just thought it was mildly interesting that WUWT has another article rejecting basic science. In this case, rejecting chemistry and biology.
From the WUWT comments
One of the commenters at WUWT goes even further and disputes the denier meme that "CO2 is plant food". Doug Proctor says (extract):
Have a look at the details of the Keeling CO2 curve. There is a very odd SINGLE cycle to the rise and fall during the year. The peak is in late April, and the lowest level, in end September, beginning October. The annual rise is the difference between the rise and fall, of course, and attributed to power-plant, fossil fuel use. The cycle is attributed to “natural causes”. Yet what processes start net CO2 production in September and end net production in May? And why only one?What processes indeed!
Beenstock, Michael, Yaniv Reingewertz, and Nathan Paldor. "Polynomial cointegration tests of anthropogenic impact on global warming." Earth System Dynamics 3, no. 2 (2012): 173-188. doi:10.5194/esd-3-173-2012
Pretis, F., and D. F. Hendry. "Comment on" Polynomial cointegration tests of anthropogenic impact on global warming" by Beenstock et al.(2012)–some hazards in econometric modelling of climate change." Earth System Dynamics 4, no. 2 (2013): 375-384. doi:10.5194/esd-4-375-2013
Lüthi, Dieter, Martine Le Floch, Bernhard Bereiter, Thomas Blunier, Jean-Marc Barnola, Urs Siegenthaler, Dominique Raynaud et al. "High-resolution carbon dioxide concentration record 650,000–800,000 years before present." Nature 453, no. 7193 (2008): 379-382. doi:10.1038/nature06949