US Sen. Ed Markey came out on Wednesday for City Councillor At-Large Michelle Wu’s mayoral campaign, citing her version of the “Green New Deal,” a localized proposal to deal with the withering effects of climate change.

Markey’s support puts both Massachusetts senators behind Wu’s campaign. US Sen. Elizabeth Warren endorsed Wu, a former student of hers and a Senate campaign aide, earlier this year.

“Her proposals to expand access to free public transportation, decarbonize our economy, and invest in the basic rights of clean air and water will put Boston on a path to implement the systemic changes we need to provide our children, workers, and families a just and livable future,” Markey said in a statement.

Wu’s “Green New Deal” proposal includes an “Urban Climate Corps,” which would involve a paid training program for young people and residents to work in neighborhoods and focus on “green infrastructure installation, climate resilient design, the restoration of natural spaces, and community engagement,” according to her website. Wu has also called for a fare-free public transit system.

Markey, a Malden Democrat, was reelected to another six-year term in 2020 after besting US Rep. Joe Kennedy III in a Democratic primary. Wu’s rival in the mayoral race, City Councillor At-Large Annissa Essaibi George, endorsed Markey, and his campaign manager, John Walsh, told the Boston Globe she was the only one.

Markey and Kennedy both supported a “Green New Deal” at the national level, but Markey, a 74-year-old incumbent who has spent decades in Washington, drew the support of New York Rep. Alexandria Ocasio-Cortez and enthusiastic young supporters. A fellow member of Ocasio-Cortez’s “Squad,” Boston Rep. Ayanna Pressley, endorsed Wu late last week.

“Senator Ed Markey’s bold vision has inspired activists, young people, and so many community members to lead, and I am honored to have his support,” Wu said in a statement. “Throughout his career, he has been a steadfast advocate for working families, environmental justice and a more equitable city, state and nation.”

Throughout the mayoral race, Wu’s campaign has pulled in support from environmental groups. Some of that support has come through super PACs, outside groups that can raise and spend unlimited amounts of money. The groups are prohibited from coordinating with the campaigns they support.

One pro-Wu super PAC, helmed by a former aide to Sen. Warren and known as the “Boston Turnout Project,” has taken in $150,000 from the Green Advocacy Project, a Palo Alto, Calif.-based group with board members who worked on Bernie Sanders’ 2016 presidential campaign. The super PAC has aired two TV ads and poured money into digital advertising on Facebook and Instagram.

A second pro-Wu group, a super PAC tied to the Environmental League of Massachusetts, has taken tens of thousands of dollars from the D.C.-based League of Conservation Voters. The super PAC, which has focused on mailings and digital advertising, has received $100,000 from the Green Advocacy Project.

Essaibi George, who has two super PACs of her own, has said they should get out of the race, while Wu has called for the groups to stay positive.

A spokesperson for the Environmental League’s super PAC told the Reporter on Sept. 22 that the group is “focused on electing leaders who will protect us from the effects of climate change and lead on environmental issues.” The spokesperson added, “In this historic election, our goal is to amplify Michelle Wu’s positive vision and proven approach to addressing the serious challenges before us through a climate lens.”