This Day In History: December 17

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On December 17, 1963, one of the first major pieces of environmental legislation in the United States becomes law. The Clean Air Act empowers federal and state agencies to research and regulate air pollution, marking a major expansion of government efforts to fight back against the damage being done to the climate.

A 1955 law, the Air Pollution Control Act, had allocated $15 million to the study of air pollution across the country. As the federal government and the states conducted this research, it became clear that further legislation would be needed. After passing through Congress relatively swiftly, a stronger act was signed into law on December 17, 1963 by President Lyndon B. Johnson, who had been in power for less than a month following the assassination of John F. Kennedy.

The landmark act and its subsequent amendments—updates were passed in 1967, 1970, 1977 and 1990—comprise some of the most comprehensive air-quality legislation in the world. Shortly after its creation in 1970, the EPA began using its powers under the CAA to set quality standards for areas affected by air pollution, and it has subsequently been invoked to ban specific harmful chemicals and tackle specific environmental problems such as acid rain or the chlorofluorocarbons (CFCs) which directly contributed to the “hole” in the Ozone Layer. Though there is a very long way to go, national emissions dropped 63% between 1980 and 2015, despite overall economic growth and an increase in the number of miles driven over that time, thanks largely to the provisions of the Clean Air Act and its successors.

READ MORE: Climate Change History