In the context of a severe drought in Sub-Saharan Africa, President Richard Nixon’s advisor, Daniel Moynihan, sent a memo to the administration on the "carbon dioxide problem." He cautioned that rising CO2 levels could heat the earth and cause sea level rise. He urged the administration to get involved with the issue. The memo was sent while the administration was conceptualizing the creation of an agency that, a year later, became the Environmental Protection Agency.
Daniel Moynihan memo to Richard Nixon, September 17, 1969