The greatest environmental treaty in history might not have happened without George Shultz.

As evidence mounted in the 1980s that chemicals from air conditioners, sprays and foams were destroying the ozone layer, a protective blanket around Earth that blocks harmful radiation, Shultz briefed President Ronald Reagan on the need to reach an international agreement to phase out the chemicals.

The U.S. should back the ozone treaty, which became the Montreal Protocol, Shultz told Reagan, pitching the move as “insurance policy” and beating back opposition from other Republicans at the time, including administration officials.

George Pratt Shultz, who died Saturday on the Stanford University campus at age 100, was lauded for serving Republican presidents starting with Dwight Eisenhower in the 1950s through Reagan in the 1980s and was widely known for his work shaping economic and foreign policy in the late 20th century.

But Shultz, whose views in support of taxing carbon pollution and prioritizing climate change as a hulking threat diverged sharply from the present Republican Party that eschews pricing emissions, also carved a long-standing environmental legacy.

Shultz was “instrumental” in establishing the Montreal Protocol — reached in 1987 and put into force in 1989 — said John Cruden, assistant attorney general for the environment and natural resources division of the Justice Department from 2015 until January 2017.

Letter to Meese

In a confidential letter, later declassified, Shultz told Edwin Meese III, attorney general to Reagan, of the growing scientific consensus at the NASA and the National Oceanic and Atmospheric Administration that human-made chemicals were eroding the ozone layer.

The data were clear: chlorofluorocarbons and halons, a family of compounds used as refrigerants, foams, sprays and solvents, were disintegrating the protective ozone boundary.

“I wanted you to know of my strong personal interest in the early and successful completion of an effective international treaty to protect the stratospheric ozone layer through reducing use of certain chlorofluorocarbons (CFCs) and halons,” Shultz, then the secretary of State, wrote in the letter. “Although scientific certitude is probably unattainable, I am impressed by the growing international consensus on the threat to the ozone layer, largely due to research by our own NASA and NOAA.”

With Reagan, Shultz took a conservative line, pitching an international treaty for its defensive merits.

“I remember when, in the Reagan administration, we found that the ozone layer was in danger of depleting. Most scientists thought it was happening. Some questioned it, but they all agreed that, if it happened, it would be catastrophic,” Shultz said in a 2013 interview with the Bulletin of the Atomic Scientists. “I talked with President Reagan a lot about it, and I said, ‘We should take out an insurance policy,’ and the Montreal Protocol came about as a result of that.”

The Senate unanimously ratified the Montreal Protocol in 1988, and former U.N. Secretary-General Kofi Annan hailed it as “perhaps the most successful international agreement to date” on any topic.

The former advisor to presidents applied the pragmatic logic from the ozone negotiations of the 1980s to climate change decades later.

“And it seems to me we can say to people who are skeptical, ‘Look, shouldn’t you take out an insurance policy? Maybe you’re wrong but the consequences are bad, and actually, the insurance policy isn’t that expensive,’” he told an interviewer.

Carbon taxes used to have bipartisan support. “I wish we would just talk about a carbon tax, 100 percent of which would be returned to the American people,” former Sen. Bob Corker, R-Tenn., said in 2009.

Republican and Democratic economists have long supported them. Art Laffer, the conservative economist and former advisor to ex-president Donald Trump backed a carbon tax. So did Milton Friedman, an economic godfather of modern American conservatism.

Endorsement

While the Republican Party’s support for charging companies fees for air pollution waned, Shultz endorsed carbon tax legislation filed by Rep. Ted Deutch, D-Fla., in the 116th Congress that would have charged $15 per ton of emissions and ramp up $10 every year.

Mirroring the slackening GOP support for carbon taxes, just one Republican — former Rep. Francis Rooney, R-Fla. — out of 86 total cosponsors signed on to the bill.

Shultz advised the Citizens’ Climate Lobby, a non-partisan group that presses for a carbon tax that would return the revenue to the public. He also established the Climate Leadership Council, which started promoting an industry-backed $40-per-ton carbon tax plan in June 2017, and wrote the Securities and Exchange Commission in 2016 to prompt firms it regulates to explain publicly how climate change might affect operations.

“We recommend that the Commission now move to promote and enforce mandatory and meaningful disclosures of the material effects of climate change on issuers,” Shultz wrote the SEC with two other former Treasury secretaries, Henry Paulson and Robert Rubin.

In the Nixon administration, Shultz was secretary of Labor and Treasury, as well as the budget director for the White House. Before joining the Reagan administration, he was an executive at the Bechtel Group, an engineering and construction firm.

Trained as an economist, Shultz supported government steps to levy taxes against polluting industries, including through a tax mechanism that would send the revenue back to the public.

“The effects on the environment are not a natural part of costs” of doing business, he said in the 2013 interview. “So you need a way to make all forms of energy bear these costs, and a tax on pollution — on carbon — is a good way to do it.”

Speaking in October 2019 at Stanford, Shultz said the wake of climate change is obvious.

“With all due respect to the science, which I appreciate, you don’t have to rely on science. All you have to do is use your eyes. There is a new ocean being created in the Arctic. Why? The ice mass over Greenland is melting fast. Why? The Great Barrier Reef and other reefs in the Caribbean are all deteriorating. Why? And the answer is always the same,” he said. “There is no question, no question, that the earth is warming, and there’s no question that there are consequences.”