claim: Fourth Assessment Report (AR4), in which the likely range is given as 2.0°C to 4.5°C, with a best estimate of 3.0°C" (Pat Michaels)
evidence: The IPCC (2007) estimates that the expected rise in temperature due to a doubling of CO2 to be about 3 °C (5.4 °F), ± 1.5°.