– Perhaps the most revealing moment at this year’s U.N. climate talks came on Wednesday, when German Chancellor Angela Merkel addressed the nearly 200 nations gathered here.

After declaring that “climate change is an issue determining our destiny as mankind,” Merkel acknowledged that Germany was likely to miss the goals it had set itself for cutting greenhouse gas emissions by 2020 because of its continued reliance on coal power. While vowing to grapple with the issue, she said that phasing out coal use would require “tough discussions” with German policymakers in the weeks ahead.

On one level, it was a stark reminder that the real action on global warming does not unfold in international venues. The problem will largely be addressed by governments back home trying to adopt policies to shift away from fossil fuels, by businesses perfecting and deploying clean energy technologies, by city planners reworking their local transportation systems.

Keeping one another honest

But Merkel’s speech was an example of what diplomats are trying to achieve. As the two-week Bonn talks concluded on Saturday, negotiators said they had made headway on creating a formal process under the 2015 Paris agreement in which world leaders would regularly and publicly detail the efforts they are making to address climate change, pinpoint areas where they are falling short, and push one another to do more.

It is, in effect, a giant bet on the power of peer pressure — with the future of the planet at stake.

The Trump administration’s vow to withdraw the U.S. from the Paris accords by 2020 has made that dynamic more complicated. While State Department officials still attended the talks and helped shape rules around how countries will report their progress on emissions, the world’s richest nation is no longer seeking to lead the fight.

Virtually everyone at the Bonn conference acknowledged that the world’s nations are still failing to prevent drastic global warming.

“We need more action, more ambition, and we need it now,” said Patricia Espinosa, the U.N. climate chief.

At Paris, nearly every country submitted a voluntary pledge for constraining its emissions. Yet those pledges are modest: Even with them, the world is still on course to warm at least 3 degrees Celsius (5.4 degrees Fahrenheit) this century, an outcome that carries far greater risks of destabilizing ice sheets in Greenland and Antarctica, drastic sea-level rise and more extreme heat and drought.

So, at Bonn, diplomats focused on ways to encourage countries to ratchet up their ambitions. Next year, world leaders will meet to assess how their efforts stack up against the goal of limiting global warming to “well below” 2 degrees Celsius.

They plan to discuss which domestic policies are working and which ones aren’t, and then try to figure out which countries can step up the pace of their emissions cuts.

Ultimately, countries plan to submit newer, stronger climate pledges to the U.N. by 2020.