In an otherwise fine article at WattsUpwithThat.com, Ari Halperin writes: For some time, the subject [of the residence time of anthropogenic carbon dioxide in the atmosphere] was surrounded by confusion, created by sloppy definitions and evasive statements in IPCC assessment reports. There was a mix-up between the residence time of a CO2 molecule in the atmosphere and the rate of change of the surplus CO2 concentration.  The residence time (~5 years) is of little interest, except as an … [Read more...]