The U.S. is using multilateral talks in Montreal to seek stronger emissions targets for aviation — and the new climate law is providing diplomatic leverage, Transportation Secretary Pete Buttigieg said in an exclusive interview with Axios.

Why it matters: Aviation accounted for just 2% of global energy-related greenhouse gas emissions in 2021, but it is growing quickly.

• Aviation, along with marine shipping, is exempt from the Paris climate agreement.

Context: Countries oversee the sector through international cooperative organizations, primarily the UN International Civil Aviation Organization (ICAO).

Driving the news: The ICAO has moved slowly to set emissions reduction goals for the industry. The U.S. is working with other countries to speed things up during an ongoing ICAO meeting in Montreal.

• The development of new technologies, from sustainable aviation fuels (SAFs) to electric planes, has helped spur a new push for tougher, albeit nonbinding, targets.

What they're saying: Buttigieg said the recent policy steps the U.S. has taken, such as passing the bipartisan infrastructure law and the Democrats' climate bill, have given the country more credibility as a climate leader at the aviation summit.

• "The last time I saw some of the ministers who are here was in Glasgow for the cop talks," Buttigieg said. "And at the time, there were a lot of questions about whether the US was going to be in a position to actually support the kind of goals that we were setting."
• Now, he said, "There's enormous momentum coming into this conversation. And it's really energizing for us to be in a leadership position now."

The big picture: The administration has come to the latest ICAO meeting with a sense of urgency, he said, working to get other countries to jump on board its own 2050 net zero target for aviation emissions.

• Buttigieg said achieving this target requires a mix of using SAFs, advancing new propulsion technologies, air traffic control and routing reforms that provide flights with more direct, fuel-saving paths, and other measures.
• Through the new laws, the Biden administration has incentivized SAF production through FAA grants and federal tax credits.

Between the lines: The ongoing talks are among the first international climate meetings since the new law passed, and could provide early signs of whether it carries weight with other countries.

• While SAFs are not a zero carbon fuel, they can reduce the life cycle carbon footprint of flying, and are part of a portfolio of solutions, Buttigieg said.
• He noted that SAF production has to be dramatically scaled up to make a dent in aviation's greenhouse gas emissions, and said the U.S. is taking steps to do that.
• "SAFs is probably the single biggest tool that we have to advance the decarbonization of this sector but it is not the only one," he said. "We have to recognize that while there are remarkable things being done in terms of new kinds of aircraft and new forms of propulsion that will be making a big difference by the middle of this century, we can't wait that long."
• The ICAO proposal the U.S. is backing would also adopt a lower baseline for a carbon offsetting and reduction program, known as CORSIA, to make it more stringent.

Yes, but: The closely followed Climate Action Tracker examined the ICAO proposals, including net zero by 2050, compared to what is needed to achieve the Paris Agreement's 1.5-degree temperature target.

• The group rated them as "highly" to "critically" insufficient.

What's next: The climate package is likely to be formally considered early next week.