I'm back to my hobby of reading old Scientific Americans. The Sept. 1971 issue is a revelation. Forty years later, it's well worth revisiting.
It's a theme issue on the flow of energy in the terrestrial biosphere and human society. The various authors were well aware that the earth's supply of fossil fuel was limited, and that the exponential growth in fossil fuel consumption was unsustainable in any case because of various externalities. Nevertheless they were generally quite sanguine about the future because they presumed, without dissent, that nuclear power would be the solution.
The possibility of climate change caused by C02 emissions had occurred to people by then, though only writer, Chauncey Starr, mentioned it:
The combustion of fossil fuels, no matter how efficiently done, must always produce carbon dioxide. It's concentration in the atmosphere has increased from 290 PPM to 320 within the past century and may increase to 375 or 400 ppm by the year 2000. [Pretty much spot on -- it's now about 390 -- C] The mechanism for removal of CO2 is only partly understood; it is eventually absorbed by the ocean, converted into minerals, or incorporated by plants in their growth . . . Its effects while it resides in the atmosphere are not now predictable, although theoretically the increased carbon dioxide should cause a "greenhouse effect" by reducing the infrared heat loss from the earth and perhaps raising the mean global temperature one degree Celsius by the year 2000.
(In fact the temperature rise since 1970 has only been about half a degree Celsius, although it is a full degree since 1910 or so. The half-degree change is already turning out to be quite unpleasant.) On the other hand, Starr continues, suspended particulates have the opposite effect, by reflecting sunlight before it reaches the earth's surface, so "the observed temperature trends are not meaningful and the subject is not well understood." Nevertheless, if you are, or rather were, still worried:
In any case we have several decades for determining the carbon dioxide pathways in our biosphere. If carbon dioxide additions to the atmosphere are determined to be harmful, there is an ultimate but costly technological solution: we could use nuclear power to manufacture hydrogen by the electrolysis of water. Hydrogen would make an ideal fuel because its combustion yields water as an end product.
So, problem solved! Whoops, that hasn't worked out so well. I'll have more on the view from 40 years back anon.