The marginal direct contribution of CO2 to the predominent greenhouse warming by water vapour has never been challenged since Tyndall. Experiments before Callendar established a contribution around the 4 and 14 microns bands of the IR part of the spectrum. This data above is from experiments in the 1950s. This is the ‘simple science’ that is not in dispute. However, IPCC projections of runaway warming proposes that the CO2 warming triggers a net positive feedback.
