On Monday March 9, 2020, just before the coronavirus lockdown, I hosted a pre-Earth-Day teach-in on auto efficiency. It was part of the commererative week of action that the University of Michigan had planned to celebrate the 50th anniversary of the first Earth Day, April 22, 1970.
In 1970, awareness of the need to far better protect the environment was growing, triggered by the many forms of out-of-control pollution that were afflicting communities across the country and across the world. Automobile pollution was one big part of huge environmental problems overall and, at the time, the focus was very much on smog-causing tailpipe emissions. The Clean Air Act Amendments of 1970, signed by President Richard Nixon later that year, established the first truly stringent motor vehicle emission control regulations. Those tailpipe standards fully took effect in 1975 and were tight enough to require the use of catalytic converters on nearly all new cars. Successive rounds of those standards led to the far cleaner vehicles we have on the road today.