Arguably yes. We had people thinking about the issue of carbon emissions in the early 1900s. Arrhenius talked about the greenhouse effect in 1890 or so.

By 1960 we had clear evidence CO2 in the atmosphere was rising, and we had fairly clear evidence it influences the climate.

In 1965, the presidential science advisory committee warned of the problem in an official report.

By 1970, the American Petroleum Institute had a study from Stanford that they commissioned, confirming the problem. From then on, the oil industry actively engaged in propaganda to discredit that science.

So, even if he didn't get it right when he started, he knew by mid-career. And he happily continued selling out.