Last October, top executives from some of the world’s most powerful oil companies testified before the House Oversight Committee about their industry’s climate change disinformation campaigns. For the past 30 years, Big Oil has spent hundreds of millions of dollars on advertising, political campaigns, super PACs and a network of think tanks. Using tactics from the tobacco industry, they have manufactured doubt about climate science and environmental regulation. At the hearing, the executives deflected, touting their support of clean energy while denying their role in misleading the public about the cause of climate change: the use of their products.

Their PR campaign is working.

Climate protectors have fallen behind in the messaging war with the petrochemical industry. And it is a war — it has been understood as such by chemical companies since the first Earth Day in 1970 when they decided to use their PR offices to discredit concerned citizens and dismantle the federal regulatory state.

Earth Day began in the University of Michigan’s basketball arena on March 11, 1970, when nearly 14,000 people attended a teach-in on the environment. The event included performances by the folk singer Gordon Lightfoot and the cast of “Hair,” speeches by Sen. Gaylord Nelson (D-Wis.) and ecologist Barry Commoner, and symposia on pesticide pollution, nutrient runoff in the Great Lakes and the new field of environmental law. The organizers, Environmental Action for Survival (ENACT), used grass-roots protest strategies developed by Black civil rights activists and anti-Vietnam War protesters, and it worked. That spring, their Michigan event served as a template for organizers at some 2,000 colleges and several thousand more schools across the country.

Dow Chemical, headquartered north of Ann Arbor in Midland, was paying attention. Speaking to the Chemical Public Relations Association in New York City that March, Dow’s director of public relations, Ned Brandt, predicted the Earth Day teach-ins probably would be “a mixed blessing” for the chemical industry. The hazard was that students might embarrass a local plant, take legal action, or organize a boycott or “some other form of trouble.”

The opportunity, though, was enormous. The industry had the chance to seize control of the environmental narrative. “If we could have a thousand representatives of the chemical industry telling about their concern and their efforts to control pollution on a thousand campuses, to the generation of tomorrow,” Brandt argued, “that would be the greatest public relations effort this industry could make just now.”