Christine Todd Whitman was at the first Earth Day 48 years ago, long before she became governor of New Jersey and head of the Environmental Protection Agency.
Her generation was inspired by "Silent Spring," a book about the dangers of the pesticide DDT, she said. Soon after that day in 1970, DDT was banned — one of many green-friendly policy moves the U.S. has made since, as the country gained a greater environmental consciousness and researchers revealed the dangers of climate change.
On Earth Day this Sunday, thousands will travel to the National Mall for the second-annual March for Science, many of them millennials, the generation whose youngest members are now graduating from college. They'll aim their signs and speeches at President Donald Trump, who last year pulled the U.S. out of the Paris climate agreement and wants to revitalize the coal industry even as renewable energy is finally becoming profitable.
Whitman believes millennials have stepped up to the plate to advocate for sustainability, lately more than her own generation — she's seen some complacency on the issue. But if millennials want change to stick, she said that young advocates will need to learn to work with the Trump administration and Congress.
"They are turned off by it, understandably. But if they want these changes they need to work with the government," Whitman said.
Some millennials have other things in mind.
Emily True, a 25-year-old graduate student studying environmental management at Duke University, has seen companies lead the charge on climate change and thinks legislation won't get the country where it needs to be. She's looking to the private sector, where she hopes to land a job where she can still fulfill her passion for advocacy.
"Part of who I am is an environmentalist, and in a job I want to do the same thing," she said. "It makes me feel good and gives me a sense of purpose."
True is among the millennials at U.S. universities working to make up for what they see as a lack of focus by the generation they are succeeding. She's a member of Duke's United Nations Global Compact team and a brand impact analyst for sustainable development nonprofit Fair Trade USA.
"Now a lot [millennials] want to have more out of their jobs to do social good, and that can come through positive work on the environment," True said.
She also thinks she feels a stronger responsibility to advocate for sustainability than her parents did at her age, saying they were probably too focused on climbing up the career ladder while she's had a chance to watch these issues unfold.
There may be something to that feeling, according to Paul Shrivastava, chief sustainability officer and director of the Sustainability Institute at Pennsylvania State University.
The millennial generation feels a keen sense of responsibility, he said — certainly a keener sense of responsibility than his own Baby Boom generation.
"They have been brought up in an era of climate change and ecosystem destruction, which are reported on almost daily in the press. So they know more about these environmental problems," Shrivastava said in an email.
"Sustainability has always been about the coming generations, and millennials and youth in general will bear the biggest risk and responsibility, so their engagement and leadership is most necessary," he added.
Today, millennials are the generation most likely to see "solid evidence" of global warming, according to a Pew Research Center study from March 1.
About three quarters of millennials are concerned about climate change — a larger share than are concerned about gun violence or undocumented immigration — and think it should be stopped or slowed, according to the 2018 Millennial Report, released in February by the Alliance for Marketing Solution, a conservative policy group that advocates for market-based environmental change.
"I think we as millennials just know so much more because of iPhones, globalization and we see things when they're happening and not afraid to take a stand," True said. "The information piece is huge."
Izaiah Bokunewicz, a sophomore agricultural plant science student at Penn State, invests much of his time into the school's one-acre student-run farm, where he oversees the production of vegetables and advocates for decreasing waste on the farm and around campus.
"At Penn State, that's been my huge activity of involvement, with food and how we can really try and decrease food waste. That's an enormous problem, [along with] increasing student access to fresh local produce and telling them how food is produced," Bokunewicz said.
An internship with a Pennsylvania company that makes LED lights taught him the importance of the emerging sustainability sector that he hadn't known much about. He said he applies what he learned there to other areas of sustainability at the school's farm.
Leslie Pillen, Penn State's sustainable student farm design coordinator and associate director of farm and food systems, said that she thinks there is a sense of urgency, and that it is increasing. She added that she hopes the younger generation draws greater connections between issues of social justice and environmental sustainability.
"Those are deeply interrelated, and within the alternative agrifood movement, I see people making those connections more explicitly," Pillen said.
On the other side of the country, the University of California, Berkeley has multiple zero-waste initiatives that are driven by students, according to Director of Sustainability Kira Stoll, with 30 to 50 students working in paid positions on campus to help reach the goal of zero waste.
They focus on issues like how to turn plastic into raw materials and how Berkeley's offices can get vendors to deliver materials with less packaging. At the campus store, students "give away clothing and are working now on an outlet to save furniture and have it available for students," Stoll said.
She said that in an institutional setting like college, there is a chance to make a real difference: "We need all hands on board."
Whitman had a similar message: more need to commit to this work, regardless of which generation might be more actively tackling global challenges.
Having watched the environmental movement for decades, Whitman, now 71 and running her own energy consultancy business, said there was a lot of support in the early years, but she sees complacency now. When people "look up to blue skies" and don't see a problem right in front of them, they lose any sense of urgency, she said.
Things are in fact better in the U.S., she said, but more work needs to be done around the world: "We haven't really recognized the importance of the rest of the Earth."
We are all part of a huge ecosystem, Whitman said, and we must all take care of it together. She referred to a Native American saying: "We do not inherit the Earth from our ancestors, we borrow it from our children."