JASONs and National Academy of Sciences, 1979:
In 1979 the subject was addressed by the JASON Committee, the reclusive group of scientists with high-level security clearances who gather annually to advise the U.S. government; its members have included some of the most brilliant scientists of our era.
The JASON scientists predicted that atmospheric carbon dioxide might double by 2035, resulting in mean global temperature increases of 2 to 3 degrees Celsius and polar warming of as much as 10 to 12 degrees. This report reached the Carter White House, where science adviser Frank Press asked the National Academy of Sciences for a second opinion. An academy committee, headed by MIT meteorologist Jule Charney, affirmed the JASON conclusion: "If carbon dioxide continues to increase, [we] find no reason to doubt that climate changes will result, and no reason to believe that these changes will be negligible."
And then there is of course the big one, Roger Revelle writing in a report to Lyndon Johnson on ecological problems. 1965.
In 1979 and 1965 there was not significant and reliable data firmly indicating global warming (we now know that greenhouse forcing was compensated by increased pollution in N hemisphere); the predictions were made entirely from basic physics and thermodynamics, and their underlying principles still stand today. The fundamental predictions: increased infrared emissivity from additional carbon dioxide, warming surface and troposphere, cooling stratosphere, global warming, and relatively higher in polar regions, are all specific markers of increased global warming from increased greenhouse forcing (vs aerosols and increases in solar forcing), and subsequent major observational programs showed them to be true.