evidence: Long before geophysicist Michael Mann’s hockeystick graph became the icon for anthropogenic global warming, the US President’s Science Advisory Committee [now known as the President’s Council of Advisors on Science and Technology (PCAST)] cautioned President Lyndon B. Johnson that the continued release of CO2 to the atmosphere from burning fossil fuels would "almost certainly cause significant changes" and "could be deleterious from the point of view of human beings." The committee’s report concluded that there could be "marked changes in climate, not controllable through local or even national efforts." In recognition of the 50th anniversary of that first official warning from scientists to policy-makers, the American Association for the Advancement of Science (AAAS), the Carnegie Institution for Science, the American Meteorological Society, and the Linden Trust for Conservation sponsored a 1-day climate symposium on 29 October. [...] It’s also true, though, that climate scoffers often charge that scientists’ climate consensus has been mostly made up, ad hoc, and comparatively recent and that it hasn’t really evolved methodically from sensibly conducted research. That’s why Inside Science News at the American Institute of Physics published and circulated Peter Gwynne’s 2014 article "My 1975 ‘Cooling World’ story doesn’t make today’s climate scientists wrong." It carried the subheadline "It’s time for deniers of human-caused global warming to stop using an old magazine story as ammunition against the consensus of today’s climate scientists."