People protesting against the global climate crisis on September 20, 2019 in New York City. Photo: Spencer Platt/Getty Images

More than 170 of the world's most esteemed environmental activists signed on to an open letter on Monday urging their supporters to vote for Joe Biden rather than vote for the Green Party or sit out the election, The Daily Beast reports.

The big picture: The group says "progressives who vote for the Green Party candidate, or write in Henry David Thoreau, or refuse to vote at all" will help win the election for Trump, whom they excoriated for his "unprecedented malignancy, fear mongering, pathological lying, and atrocious policymaking."

  • Flashback: Trump won in Michigan, Wisconsin and Pennsylvania in 2016 by smaller margins than the total votes cast for Green Party nominee Jill Stein in each state, The Daily Beast notes.
  • Signatories to the letter include the likes of Earth Day founder Denis Hayes and Environmental Action coordinator Peter Harnick.

What they're saying: “Angry right-wing voters and liberal absentees put Trump in the White House in 2016. In 2020 the same unholy team could keep him there," the letter reads.

"Sure, [Biden] isn’t perfect. Which of us is? But in the 2020 election, the most crucial since 1865, we have only two meaningful options. We can make a lifetime humanitarian our president, backed by an able cabinet and a progressive Congress; or expand the strongman rule of Donald Trump, who desecrates his office every day, spreads racism and a fatal virus for political gain, ignores environmental justice, embraces the fossil fuel industry, and calls the climate crisis a hoax."

Read the full letter.

Go deeper: Why Biden and the Democrats went big on climate

Go deeper

The Biden blowout scenario

Joe Biden speaks at an outdoor Black Economic Summit in Charlotte yesterday. Photo: Kevin Lamarque/Reuters

Joe Biden or President Trump could win the election narrowly — but only one in a popular and electoral vote blowout. 

Why it matters: A Biden blowout would mean a Democratic Senate, a bigger Democratic House and a huge political and policy shift nationwide.

National security officials endorse Biden

Photo: Jim Watson/Getty Images

A group of 489 former national security leaders, including Paul Selva, a retired four-star general and the vice chairman of the Joint Chiefs of Staff under Trump, have endorsed Joe Biden for president.

The big picture: Among the names signing Thursday’s letter: Sean O'Keefe, a former Navy secretary for President George H.W. Bush; Richard Armitage, deputy secretary of state for President George W. Bush; and Admiral Steve Abbot (ret.) who also worked in the last Bush White House.

Sanders: "This is an election between Donald Trump and democracy"

Photo: BernieSanders.com

In an urgent appeal on Thursday, Sen. Bernie Sanders (I-Vt.) said President Trump presented "unique threats to our democracy" and detailed a plan to ensure the election results will be honored and that voters can cast their ballots safely.

Driving the news: When asked yesterday whether he would commit to a peaceful transfer of power if he loses, Trump would not, and said: "We're going to have to see what happens."