When asked where he got the motivation to persist in his fight against climate change, former School of Forestry and Environmental Studies Dean Gus Speth ’64 LAW ’69 compared himself to Sisyphys — the mythical Greek king condemned to an eternity of rolling a boulder uphill and watching it roll back down.

He used this metaphor to tell budding activists in the audience that the most important thing is to have a cause they are dedicated to. Speth — who spoke to about 20 students at a Branford College Master’s Tea Monday — has served as administrator of the U.N. Development program, chairman for the U.S. Council on Environmental Quality and co-founder of the Natural Resources Defense Council. At the tea, he discussed the challenges facing the fight for environmental justice and the measures he believes should be implemented to prevent climate change — ideas that he said are featured in his upcoming memoir “Angels by the River.”

Although he is hopeful for the future, Speth said he acknowledges that institutional responses to address climate change will be slow. When he worked for the Carter administration in 1980, the government already knew enough about climate change to know the problem was serious, he said.

“Are we going to have to be hit way too hard before we take it seriously? I’m afraid so,” he said. “But the important thing is to be crisis-ready — to have things moving already and to have examples of success. Then, when people finally look for solutions, they’ll find them.”

Though Speth said he has made considerable strides in the movement to stop climate change, through his work with the NRDC and the U.N., he believes that collective efforts have not been drastic enough.

The political economy in America is not serving the interests of human beings and the environment. He said he hopes markets will become less important in daily life and that there will be a new generation of corporations that support worker-owned companies, public-private hybrids and social enterprises. Only then, he said, will power leave the hands of large fossil fuel corporations, allowing the planet to recover from carbon emissions.

Speth also said he is deeply disappointed in the University’s refusal to divest from fossil fuel corporations earlier this year. Stanford University, he said, set a much better example by divesting from coal companies. Universities have the opportunity, and responsibility, to make the decision to dissociate from the practice of investing in fossil fuels, he added.

As part of a discussion of his memoir, Speth also talked about his upbringing in a segregated Southern town, which exposed him to racial tensions early on in life. During his years as an undergraduate at Yale, Speth said, he became passionate about fighting racial inequality — which inspired him to pursue a career in social activism. Speth said he eventually transitioned from racial activism to environmentalism.

To some degree, he said, the civil rights movement parallels the battle for environmental justice.

While it is now clear to the American public that racism is a great crime, not as many people feel directly affected by climate change, he said. This is a problem, Speth added, because the situation is rapidly changing.

“The grievance issue in the civil rights movement was easy to identify,” he said, “Sadly, the victimization of people by climate change is increasing. I think we’re going to see far more of that as time goes on.”

Audience members interviewed said they largely agree with Speth’s opinions.

Tristan Glowa ’18 said Speth provided a motivating example for people passionate about environmental justice.

“I loved it,” Glowa said. “It’s easy to get disheartened when trying to change large institutions, and it’s good to remember that we have a voice in the fight.”

Riddima Yadav ’18 said she was glad to meet someone who has taken such a strong stance on these social issues.

The NRDC has over 1.4 million members.