Douglas Cotton, physicist: There is no valid physics which links carbon dioxide with the (natural) warming of Earth, Venus or any planet. Solar radiation mostly passes straight through the thin transparent surface layer of the oceans, whilst "back radiation" does not penetrate at all. Yet it is assumed that the total flux of both can be stuck into Stefan-Boltzmann calculations in order to "explain" the observed mean surface temperature. Editor, John Shanahan's Note: Greta Thunberg, Al Gore, President Obama's Science Advisor - John Holdren, Michael Mann, James Hansen, Pope Francis, their peers, followers and many others are very wrong. Stopping use of fossil fuels would be a disaster as bad as global war. Physicist Douglas Cotton explains climate science and what energy we should use very well.