C E N T E R F O R I N T E R N AT I O N A L E N V I R O N M E N TA L L AW © tekila918/Pixabay 14 Air Conservation on carbon dioxide— reproduced almost entirely in the NPC report—was dramatically shorter, less detailed, considerably more equivocal than the industry’s own 1968 report, and failed to mention Revelle’s landmark paper from 1957, as well as several other leading assessments.109 The Robinson and Robbins reports, read in conjunction with explicit references thereto in an industry-authored 1972 report demonstrates that by no later than 1968, the petroleum industry as a whole was on notice of climate change, its most probable causes, its potential risks, and the pressing need to research technologies to reduce carbon dioxide emissions. From 1977 to 1982 Exxon Scientists Repeatedly Confirm the Science of Climate Change Investigations and document releases have demonstrated that, by no later than the late 1970s, scientists employed by Exxon were reiterating to top management both the degree of certainty within the science and the scale of possible impacts. In 1977, Exxon scientist James Black informed the company’s management committee that climate change driven by fossil fuel use posed a significant global threat.110 Later that same year, an interoffice memo from Henry Shaw, another Exxon scientist, noted that the “CO2 problem … is the most important manmade weather problem that we have to contend with.”111 In May 1978, Black gave a presentation that included a prediction that a doubling of CO2 in the atmosphere would produce a temperature increase of two to three degrees Celsius. He noted that, despite any uncertainties about the state of science at the time, “there is no guarantee that better knowledge will lessen rather than augment the severity of the predictions.”112 He reiterated that the growth in carbon dioxide in the atmosphere was due primarily to fossil fuel combustion, and he concluded that “man has a time window of five to ten years before the need for hard decisions regarding changes in energy strategies might become critical.”113 By 1980, the scientific consensus was being openly acknowledged by Exxon scientists. Exxon’s December 1980 Technological Forecast warned that “most widely accepted calculations carried on thus far on the potential impact of a doubling of carbon dioxide on climate indicate that an increase in the global average temperature of 3 ± 1.5ºC is most likely … with greater warming occurring at the …polar regions.”114 The forecast also noted that projections calculating smaller temperature increases “are not held in high regard by the scientific community.”115 Documentary evidence demonstrates that similar findings were being presented to and discussed within API as a whole.116 This understanding was also communicated in a 1980 report from Imperial Oil, Exxon’s Canadian subsidiary, entitled Review of Environmental Protection Activities for