WASHINGTON — Greenpeace USA released a scorecard on climate policy for 2020 candidates on Thursday, giving Washington Governor Jay Inslee its highest marks while placing former Vice President Joe Biden and Colorado Governor John Hickenlooper at the bottom of the Democratic pack.

"We are in a climate emergency. Yet for the last several elections, even the majority of politicians who claim to care about our future have done little more than say they believe the climate crisis is real," Greenpeace USA Climate Campaign Director Janet Redman said in a statement announcing the grades. "That doesn’t cut it anymore. In 2020, true climate leadership means nothing less than saying 'yes' to a Green New Deal and 'no' to fossil fuels."

While Biden received a D-, his low grade "is primarily due to lack of info" on his positions, Greenpeace USA spokesman Ryan Schleeter told NBC News, suggesting he may have room to improve.

The scores were based on positions taken since 2013 and "gave zero credit" to candidates with "no apparent record" on a given issue.The group's write-up of Biden indicated it was basing its grade off indicators like a speech he gave to a mayors conference this year and some past comments as vice president.

Biden has yet to fill out his policy platform on climate change, but has called it an "existential threat" and cited his work on climate-related legislation as far back as the 1980s. A spokesman for the Biden campaign declined to comment on the rankings.

The rankings graded candidates on a 1-100 scale across two broad categories, each with their own sub-components. One, their support for the Green New Deal resolution and its demand for a rapid transition toward net-zero carbon emissions, and two, their support for phasing out all fossil fuel, a concept that was left out of the resolution and has divided 2020 Democrats. Only five candidates received even minor partial credit from the group for supporting a "managed phase-out domestic fossil fuel production" before 2050.

They also graded candidates on whether they had pledged not to take money from organizations or executives tied to the fossil fuel industry.

Inslee, who earned an A- grade, has made climate the primary focus of his campaign and recently released a $9 trillion climate infrastructure and jobs plan. Sens. Bernie Sanders, I-Vt. and Cory Booker, D-N.J., each earned a B+ while Sen. Elizabeth Warren, D-Mass., earned a B, with the scorecard citing various pieces of legislation they'd signed onto, among other data points.

Inslee, Warren, Booker, Sen. Kirsten Gillibrand, D-N.Y., and Rep. Tulsi Gabbard, D-Hawaii, each filled out a 29-question survey for the group. For the others, the group based their grade off their public positions, legislation, and comments.

Former Rep. Beto O'Rourke, who released his own $5 trillion climate plan, earned a B-. O’Rourke's run was greeted with some skepticism by environmentalists after he broke with Democrats on legislation lifting a ban on oil exports — a position Greenpeace docked him points for in its grades — but the Texas politician has made climate a major component of his presidential run.

At the bottom were Biden and former Colorado Gov. John Hickenlooper, each of whom received a D-. Hickenlooper has clashed with environmentalists at times over his criticism of the Green New Deal and his emphasis on a cooperative approach between energy companies and climate activists to negotiate policy.

On the Republican side, both President Donald Trump and primary challenger Bill Weld, a former Massachusetts governor, earned an F.

The full rankings, below: