"Scientists at two of America's biggest automakers knew as early as the 1960s that car emissions caused climate change, a monthslong investigation by E&E News has found.
The discoveries by General Motors and Ford Motor Co. preceded decades of political lobbying by the two car giants that undermined global attempts to reduce emissions while stalling U.S. efforts to make vehicles cleaner.
Researchers at both automakers found strong evidence in the 1960s and '70s that human activity was warming the Earth. A primary culprit was the burning of fossil fuels, which released large quantities of heat-trapping gases such as carbon dioxide that could trigger melting of polar ice sheets and other dire consequences."