When Sen. Tom Udall departs the Senate in 2021, he will leave behind a weighty environmental legacy built with bipartisan help, progressive principles, and a clarion call to tackle climate change.

In a statement on Monday announcing he would not seek re-election in 2020, the New Mexico Democrat described environmental destruction to Earth as a crisis that demands pressing urgency.

“That’s why, when I go back to Washington tomorrow, I’m going right back to work,” Udall said. “To fight the urgent threat of climate change, dramatically expand clean energy and to protect our public lands and forests.”

[Sen. Tom Udall won’t seek a third term in 2020]

Udall, 70, who comes from a family synonymous in the American West with politics and conservation, joins Republican Sens. Lamar Alexander of Tennessee and Pat Roberts, of Kansas, on the list of senators who plan to retire at the end of this Congress.

“There will be more chapters in my public service to do what needs to be done,” Udall said.

First elected to the senate in 2008, Udall focused on environmental matters from the start of his term, including local pollution issues, such as toxic chemicals and asbestos, and global threats to the planet from climate change.

“He was tenacious and he was willing to work across party lines,” Elizabeth Gore, of the Environmental Defense Fund, told CQ, adding that Udall’s first bill in the Senate would have boosted requirements for renewable energy sources among electric utilities.

“He was a true environmentalist,” Gore said. “And he did it in a way that was both thoughtful and statesmanlike.”

Chief among his accomplishments is the Frank R. Lautenberg Chemical Safety for the 21st Century Act, which became law in 2016.

After then-Sen. Frank Lautenberg, died in 2013, 11 days after introducing a bill to update the Toxic Substances Control Act, Udall took up the New Jersey Democrat’s cause.

Congress passed the law overwhelmingly with bipartisan support, ushering in the first update to TSCA in 20 years. But it likely would not have happened without Udall, according to Richard Denison, senior lead scientist at EDF.

After the death of Lautenberg, who had been a public health advocate for decades, “it seemed like the end of the road really,” Denison said. “There was nobody in the wings who was there to take this up.”

Denison helped Udall on the bill and said Udall salvaged a deal with former  Louisiana Republican Sen. David Vitter, who was willing to walk away from their TSCA-reform bill entirely.

“I still don’t know quite how he pulled that off,” Denison said. “I still don’t quite know what the magic dust was.”

Jon Horning, director of WildEarth Guardians, an environmental group headquartered in New Mexico, said Udall has long been an advocate for public land protection, efforts to address climate change and bedrock environmental laws, such as the Endangered Species Act.

It seems to Horning though that the Trump administration has drawn out the fighter in Udall.

“He doesn’t bask in the spotlight, he doesn’t need the spotlight,” Horning said. Still, he added, “In the last few years he’s really put on the gloves.”

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