Gore recently endorsed the Green New Deal, a progressive, broad-brush outline of policies aimed at deeply cutting emissions while boosting employment, and a call for 100% renewable electricity.

When I said there aren’t many details of the policy, Gore responded: “I don’t know what the details are either.” He said he endorsed it because he thinks “the broad outline is pretty clear: create lots of jobs in pursuing this transition to a sustainable economy.”

Here at the climate conference, concern is growing among some nations and activists about to what extent the Trump administration is lowering ambition for the Paris Climate Agreement. President Trump has vowed to withdraw the U.S. from that deal, but Gore doesn’t think ambition is waning.

Gore said he wasn’t concerned that an Australian government official spoke in support of the Trump administration’s event earlier this week at the confab backing cleaner fossil fuels.

What’s next: Gore is referring to an election next spring for the next prime minister of Australia. Gore said the more progressive party is ahead in the polls.

It's not possible to reduce greenhouse gas emissions without reducing the use of fossil fuels, Gore said, and to try to separate those goals is "to believe in the tooth fairy.”

The big picture: The technology, which captures CO2 emissions from power plants and industrial facilities, works but has been prohibitively expensive for decades, which Gore rightly points out. That’s starting to change, albeit slowly.

Driving the news: The former vice president and longtime climate activist spoke to a packed crowd this morning at an annual United Nations conference that drew tens of thousands of attendees. We sat down in a nearby room shortly afterward to discuss a range of issues (more on others later).

• I asked him whether the focus of addressing climate change should be on getting off fossil fuels or reducing greenhouse gas emissions. It’s a subtle but important distinction gaining attention here, particularly from fossil fuel-dependent nations.
• Gore responded by asking: “What does that mean? Not getting off fossil fuels but reducing emissions? You’re not buying the CCS nonsense are you? ... Are you?” (CCS is the technology's acronym: carbon, capture and storage.)
• I replied after another pause: “Well, I don’t buy anything, as an unbiased reporter.”

Details: Gore acknowledged that the recent UN science panel report found the technology essential. He also said it technically works. One of its biggest hangups, he said, is that it costs a lot of money to execute the technology on facilities, which would divert money from a revenue stream.

• “The fact none of the existing technologies are considered ready for primetime, in the sense that nobody knows how to execute at scale, makes it a daunting challenge for sure. I’m mindful of that,” Gore said.
• He concluded: “I just think it’s an extremely improbable solution right now, but maybe they will come up with some breakthrough. There are so many fossil-fuel burning installations now that they are just shutting down well before their useful lifetime because it’s just simply cheaper to move to” renewable energy.

By the numbers: Per a new report the nonprofit Global CCS Institute released at the conference Tuesday:

• 18 large-scale co2-trapping facilities are currently operating in the world.
• 5 are under construction.
• 20 are in various stages of development.

One level deeper: Gore is right that making the financial numbers work on carbon capture technology is one of its biggest hurdles. More recent trends suggest changes are afoot.

• The economic aspect is improving in some corners, fueled in part by a recently passed law in the U.S. that gives financial incentives to companies that capture CO2.
• Since the 2015 Paris climate deal, the technology is also getting a lot more attention from different countries that are big fossil-fuel producers. This includes Australia and Middle Eastern nations as they attempt to reconcile their commitments to addressing climate change with their fossil-fuel based economies.
• Industrial sectors, such as cement and steel manufacturers, are also looking at the technology more since making those products emit CO2 in the chemical processes themselves.

What’s next: Stay tuned for more of our interview with Gore.

Editor's note: This story has been updated. A quote has been partially paraphrased to clarify Gore's position that fossil fuels must be cut back to reduce emissions.

“There is a dearth of American leadership here,” said Tom Steyer, a billionaire turned liberal activist, in one of the only small conference rooms available in the space.

Details: Steyer, who spent more than $120 million supporting Democratic issues and candidates in the midterm elections, said this conference is essential to ensure countries keep on track with the 2015 Paris climate deal, which President Trump vowed to withdraw from last year.

• Instead, the top headline coming out of the conference so far, Steyer said, is how the Trump administration joined with Russia and Saudi Arabia to resist stronger wording on a climate science report.
• “I don’t think any of those things is going to happen without American leadership,” Steyer said.
• He went so far to criticize two of his progressive colleagues, California Gov. Jerry Brown and Washington Gov. Jay Inslee, for not attending. They both came last year. Steyer speculated that for them, “it just wasn’t a high enough priority.”
• Steyer and Inslee have indicated they're considering presidential runs in 2020.

The other side: Both Inslee and Brown sent senior officials working for them, including Mary Nichols, chair of the California Air Resources Board; Ken Alex, senior adviser for Brown; and Reed Schuler, senior adviser to Inslee. Staffers for several Democratic senators are also attending.

• Nichols said last year's conference, which was housed inside a huge igloo and offered free food, drew a much bigger crowd because it was the first conference since Trump announced he was withdrawing from the Paris deal. “Now the difference is we don’t have to argue the point anymore. I would say this work is now embedded in our whole way of doing business.”
• As for Steyer’s swipe at Brown, Nichols said she spoke at three events over the past few days with Steyer and doesn't "choose to take that comment as indicative about what he really thinks.”
• Alex, sitting next to her, chimed in that with Brown, who is finishing his final term as governor, “feels he can be most effective in California.”
• Schuler, asked Monday about Inslee’s absence, echoed Nichols’ sentiment and said Inslee is showing his leadership on the issue differently. That includes a decision to unveil his climate policies this week after an initiative pricing carbon emissions failed in November’s ballot box.
• Another official involved in promoting nongovernment U.S. interests said the Polish government made the process of creating the center more difficult than last year.

What’s next: The official U.S. delegation, which includes the Trump White House, State Department and Environmental Protection Agency officials, will continue negotiations on the details of the Paris deal, with the conference officially wrapping up later this week.