Vice President Joe Biden speaks in New York City in support of raising the minimum wage, September 10, 2015. Andrew Burton AFP/Getty

Here’s a bit of trivia: The first senator to introduce a bill dealing with climate change was none other than Delaware’s Joseph R. Biden Jr.

Biden’s 1986 Global Climate Protection Act didn’t pass nor did it ignite a stampede of congressional action to stem what was then a less-known threat. (NASA scientist James Hansen’s landmark testimony on the topic wouldn’t even come until 1988.) But it has become a handy reference point when Biden touts his climate legacy.

On Wednesday, Biden made reference to the proposal in a speech at a solar-power conference. He recalled that at the time, he warned, “Reality has a way of intruding,” and now reality had made its way. As Biden considers a run for the White House, that’s a memory that could be brought up over and over again.

All of the Democratic candidates have made environment and energy a priority, and with big money coming from environmentalists like Tom Steyer, it is nearly impossible for a candidate on the left to ignore climate change. So the question then becomes, how green is Biden?

Biden’s platform over the last six years is, by nature, indistinguishable from President Obama’s. Given that it includes the biggest steps any administration has taken to tackle climate change, it would seem to be a strong starting point.

But despite the increasing interest in him as an alternative to Hillary Clinton, environmentalists don’t seem to have much interest in having Biden build on another term of the Obama climate agenda.

“I know very little about his record other than as an Obama spokesperson,” said R.L. Miller of the Climate Hawks Vote super PAC. “And there’s not much interest in it. There’s just no chatter at all.”

In a June speech at the White House, Biden even said that getting “a handle on climate change” was “the single most important thing” he and Obama could do while in office. The White House has tightened fuel-economy standards, advanced clean energy, struck climate deals with foreign governments, and enacted carbon-emission rules on power plants that could completely overhaul how the nation produces electricity.

On Wednesday, Biden announced more than $120 million to advance clean energy at the Solar Power International Conference, then joined a U.S.-China conference on climate change.

In a statement, Sierra Club political director Khalid Pitts said that Biden “has helped lead the fight to protect our communities and families from toxic pollution, so we can be sure that any public debate he is a part of is guaranteed to include a robust and thorough discussion of climate action and clean-energy issues."

But groups further to the left say that Biden is going to have to prove he would be more than just a third Obama term to get any support. Greens have been left wanting by the White House when it comes to fossil-fuel production, saying that Obama has been too eager to embrace natural gas and has done too much to open up offshore areas to oil-drilling, especially after Shell was granted a permit to drill in the Arctic this summer.

And the White House still has not announced a verdict on the Keystone XL pipeline.

Without an effort to prove he has some sunlight from the status quo, Biden’s run could thus be hurt before it even begins.

“The next president is going to have to do a lot more than Barack Obama on climate change,” said Karthik Ganapathy of 350.org. “So the question becomes, will Joe Biden be an extension of the Clean Power Plan and an ambassador of the Obama administration, or is he ready to outline an aggressive agenda?”

Front-runner Hillary Clinton has been dogged with questions from greens about where she stands on fossil fuels—even though she says that she opposes Arctic drilling, she has been silent on her stance on Keystone and has hinted that she would continue natural-gas-drilling on public lands.

That’s why some environmentalists have flocked to her left and stood behind Bernie Sanders, who has talked up climate change as a centerpiece of his campaign. He has led opposition against the Keystone pipeline, has spoken out against offshore drilling, and has called for a carbon tax in the Senate. Even Martin O’Malley has promoted a plan calling for 100 percent clean energy by 2050.

Based solely on his record, Biden would seem to come somewhere in the middle. And he has got plenty to run on, especially coming out of a White House that has emphasized the climate fight. In a 2013 interview with Rolling Stone, Biden talked up the White House’s role, especially as Congress has stood still on the issue while faced with Republican opposition.

And although it’s not an issue like gun control, where the reins were more or less handed over to Biden, the vice president has been an active player in the White House’s climate agenda. Perhaps his biggest role was in administering stimulus funds, including $90 billion in clean-energy programs, which he told Rolling Stone was “the thing I'm proudest of that we were able to get done in the first term.”

In an interview with Time in 2010, Biden talked at length about the “fun stuff” in the stimulus, which included research and development funding for smart grids, electric cars, clean energy, and other strategies to reduce fossil-fuel dependence. He recalled talking about using the stimulus to build a more advanced electric grid, saying: “'God, wouldn't it be wonderful? Why don't we invest $100 billion? Let's just go build it!'”

And Biden has been active in promoting the administration’s various climate initiatives. Speaking to the solar conference today, he said the country keeps “leading the world in a new energy transformation that’s producing cleaner and more sustainable forms of energy.”

"Our efforts to lead the world depend not on the example of our power, but the power of our example,” he added.

Environmentalists see that kind of experience as a leg up in a possible White House run, or at least a way to push Clinton further on climate change.

“To the extent that the Democratic nominee’s campaign is built around the Obama administration’s achievements, it would increase the likelihood that the platform highlights and expands upon its successful record of investments in clean energy and jobs and carbon-pollution cuts,” said Daniel J. Weiss, senior vice president of campaigns for the League of Conservation Voters.

Biden’s Senate record also shows a relatively strong history on climate change, even if the issue was not a defining one for his 36-year tenure. Biden’s 1986 bill would have established a presidential task force on the climate and required more direction of federal agencies to hold multilateral global-warming activities. It also instructed the president to discuss climate protection with the Soviet Union.

Although it didn’t pass, environmentalists say it set up a clear pattern on the issue for Biden. On the Senate Judiciary Committee, Biden harangued oil companies, including at a 2006 hearing where he challenged executives from oil giants like BP and Chevron about the subsidies the industry receives. He also backed several bills that would have required new automotive technology or tightened fuel-economy standards.

Biden also engineered several hearings on climate change on the Foreign Relations Committee, where he served as the leading Democrat for several terms. Biden also tried to whip up support on several nonbinding resolutions with Republican Dick Lugar, who also chaired the committee, trying to get the Senate to express support for international climate-change talks, although none ended up passing the Senate.

His global focus on climate change could win Biden some attention, especially with the United Nations set to negotiate a climate pact at the end of the year in Paris.

Elgie Holstein, senior director for strategic planning for the Environmental Defense Fund, said that there’s a “deep well of respect and admiration” for Biden when it comes to energy, but Holstein added in the same breath, Hillary Clinton is also an appealing candidate.

“They both represent good choices on the environment, they’re good people with great experience,” he said. “But really, neither one has rolled out extensive detailed climate or energy plans. It’s too soon to say if anyone is better than another. … We’re just anxious to encourage candidates in both parties to capitalize on the enormous changes that are occurring in energy.”

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