claim: Elementary radiative-transfer calculations demonstrate that a natural surface global brightening amounting to ~1.9 Wm–2 over the 18-year period of study would be expected – using the IPCC’s own methodology – to have caused a transient warming of 1 K ( 1.8 F° ).
evidence: Taking planetary heat uptake rate as the rate of ocean heat uptake estimated by the IPCC AR4 as 0.2 W / m2, yields a value for S of 2.1 °C ( 3.8 °F ).