Seeger, known for writing such folk hits as "Where Have All the Flowers Gone?" and "Turn, Turn, Turn," said Sunday's benefit concert at Madison Square Garden would benefit the Hudson River group, USA Today reported Friday.
Seeger said he will use the sold-out event, which will feature a performance by singer Bruce Springsteen, to remind people of how small acts can have an environmental impact.
"It's not always the big things that make a difference, but all the small things done by people who don't get attention," he said.
The singer, who has confirmed he will play one song solo at Sunday's concert, also downplayed being called a saint by singer-songwriter Bob Dylan.
"What a terrible thing to call someone," he told USA Today. "I've made a lot of foolish mistakes over the years."
The New York Daily News said Seeger and Springsteen were to be among the more than 50 performers performing Sunday.