The presentation analyses the four existing lines of proof for the CAGW hypothesis and concludes that all four fail:
The first line of proof is the “proof by contradiction”: the observed temperature change can only be explained by the known climate forcings if CO₂ is responsible for all the warming.
However, the ensemble of forcings used contains only two natural forcings — a marginal influence from the sun and intermittent cooling from volcanic eruptions. This would require either that temperatures before 1850 were essentially “flatlining”, or that the ensemble is incomplete. Since temperatures before 1850 were highly dynamic, it follows that the ensemble underlying this proof lacks an unknown but significant forcing that could readily account for most of the warming observed since 1850.
Correlation alone does not constitute scientific proof in the absence of established causation; there is therefore no requirement to disprove any correlation. Nevertheless, no timescale exhibits a convincing and consistent correlation between CO₂ and temperature — neither over 120 years, 11.000 years, 400.000 years, 600 million years, nor 4.5 billion years.
The water cycle of evaporation, convection, condensation, cloud formation and precipitation is poorly represented in climate models. As a result, almost all models predict more warming than has been observed.
Radiation physics is unambiguous: a doubling of CO₂ by itself produces approximately 1 °C of global warming. The climate system, however, contains strong feedbacks, both positive and negative. Determining the net warming that would result from a doubling of CO₂ once all feedbacks are included would require a far better understanding of the climate system than we currently possess.
The presentation concludes with a perspective on the nature of climate change. It is suggested that a warming climate essentially consists of climate zones shifting poleward away from the equator and expanding in extent — thereby providing more habitat for all species and enabling greater food production for humankind.