Holdren co-authored a book chapter with Paul Ehrlich (the honorary Failed Forecast Czar) back in 1971 entitled Overpopulation and the Potential for Ecocide. In that chapter, they forecast both a human-caused ice age and human-caused warming, with the latter being the biggest threat.
What is astounding from a science perspective is that Holdren blamed warming on waste heat, the result of humans and their energy use, rather than a slowly increasing greenhouse effect. He predicted that the localized nature of this waste heat would eventually spread to be a global problem.
But a little research and few minutes of math (which I assume Holdren learned at some point) would have revealed that humanity’s waste heat generation is, from a global perspective, trivial.
Assuming today’s global energy use is about 150 petawatthours per year, and dividing that by the number of hours in a year and the surface area of the Earth, this yields an average energy flux of 0.03 Watt per sq. meter. This is about 100 times smaller than the estimated heating from increased carbon dioxide in the atmosphere. It is almost 10,000 times smaller than the rate of solar energy input into the Earth.
It scares me that someone with so much energy policy influence has so little knowledge of basic physics.