Forty to 50 years ago there was “general agreement” in estimates of the resulting radiative forcing (1 to 2 W/m²) and surface temperature change (0.5°C ±0.3°C) when directly doubling CO2 concentrations from 280 to 560 ppm. By the late 1980s the “consensus” estimates doubled to 3.7 W/m² forcing and 1.2°C warming instead. Apparently “basic physics” … Continue reading 1970s-’80s ‘Physics’ Said Doubling CO2 Produced Just 0.2°C – 0.8°C Warming. Then ‘Physics’ Changed.