Bad paper bingo with the NIPCC: carbon cycle

It is time for bad-paper bingo: the best climate sceptics that $467,000 can buy have published their the “Not the IPCC” report.

Section 2.1.2 is concerned with the atmospheric residence time of CO2. This section relies heavily on Essenhigh (2009), who argues that the residence time is short, but omits to mention that Crawley (2011) completely dismantled Essenhigh’s arguments. Essenhigh (2009) confuses the residence time of a molecule of CO2 with the decay time of a pulse of CO2 emissions.

Starr (1992) and three work by Segalstad (1992, 1996, 1998 – none of which are peer reviewed papers)  for making the same mistake.

All that is missing for a “full house” is something by Khilyuk & Chilingar and the phantom paper by Murry Salby.

In addition to citing papers that are trivially wrong, NIPCC manage to get confused by Solomon et al (2009). Solomon et al report that after CO2 emissions cease, the “quasi-equilibrium amount of CO2 is expected to be retained in the atmosphere by the end of the millennium that is surprisingly large: typically ~40% of the peak concentration enhancement over preindustrial values (~280 ppmv).”

The NIPCC complain

“It is not known how the 40% estimate was derived.”

Which makes me wonder if the NIPCC authors know to read a paper. Solomon et al cite four papers to support their argument and show the result of the Bern 2.5CC Earth System Model of Intermediate Complexity.

The NIPCC conclude this section by asserting that

“The short residence time suggests anthropogenic emissions contribute only a fraction of the observed atmospheric rise and other sources, such as ocean and volcanic degassing of CO2, need to be sought.”

This is simply wrong. The increase in atmospheric CO2 concentration is half that would be expected if all anthropogenic emissions were retained in the atmosphere. Half the CO2 emitted is being absorbed by the oceans and terrestrial vegetation: the oceans are a net sink for CO2. A net sink cannot be responsible for the rise in atmospheric CO2. The NIPCC provide no evidence that volcanic degassing is enhanced in the late 20th century, nor do they explain why volcanic CO2 emissions, two orders of magnitude smaller than anthropogenic emissions, can accumulate in the atmosphere when they argue that anthropogenic CO2 do not.

This section of the NIPCC report is credulous, accepting arguments that even most climate sceptics think daft.