For roughly a quarter century, US climate envoy John Kerry and his Chinese counterpart, Xie Zhenhua, have sought to make headway in the fight against global warming.

Over seafood in Washington and duck in Beijing, they have set the pace for progress between the world’s biggest greenhouse gas emitters. They’ve brokered agreements for collaboration and hammered out deals that provided a foundation for global climate pacts — from the 2015 Paris Agreement to the Glasgow accord inked two years ago.

“We have a special relationship” and “great respect for each other,” Kerry said in an interview following days of talks with Xie in China this week. “We share a common interest in winning the battle of this crisis.”

But the seasoned diplomats are up against a closing window to act. The world is set to warm dangerously beyond a critical 1.5C tipping point unless the US and China — the nations most responsible for planet-warming pollution entering the atmosphere today — move swiftly to slash their emissions.

And both statesman are navigating political dynamics at home that complicate their work, as Beijing and Washington spar over trade controls, human rights and other issues. In the US, anti-China rhetoric is set to intensify as the presidential campaign heats up next year, a dynamic Kerry said makes climate diplomacy even harder.

Xi’s Stance

Similar challenges were on display in Beijing this week. Even as Xie and Kerry were working to find consensus, President Xi Jinping used remarks at an environmental conference to insist China wouldn’t allow outsiders to dictate its carbon-cutting path.

Ultimately, negotiations ended late Wednesday without a grand pronouncement — and with far more work to do in the four months before this year’s United Nations climate summit opens in Dubai. Both sides have committed to more negotiations and to “work intensively” to make progress, Kerry said.

Read More: Clock Runs Out as US-China Climate Talks End Without Deal

Both negotiators are in their 70s. Kerry, a former secretary of state and US senator, has been to many UN climate summits since a session in Rio in 1992. Xie was pulled out of retirement when Kerry was appointed the special presidential envoy for climate, and he suffered a stroke earlier this year. It’s unclear how much longer they’ll continue in their current roles.

“The irony is they find bilateral relationship at its worst just when they are about to pass the baton to the next generation,” said Li Shuo, a senior global policy adviser for Greenpeace East Asia. “The Xie-Kerry story goes beyond their personal commitment. It represents the sunset of a golden era and our anxiety of not knowing what’s next. All of this is happening when the climate crisis becomes ever more evident.”

Staying Focused

To be sure, neither Xie nor Kerry have announced any plans, and instead remain focused on the delicate work of climate diplomacy. Day after day this week they huddled over dinners in the Beijing Hotel and the Grand Hyatt blocks from Tiananmen Square, and spent more than 20 hours across the negotiating table deliberating ways to more rapidly reduce reliance on coal-fired electricity, pare methane emissions and deploy renewable power.

Following these talks, they will continue to try to keep the two superpowers’ efforts on climate walled off from other disputes in the US-China relationship, mindful that any misstep could derail progress.

That happened last year when Beijing suspended negotiations after then-US House Speaker Nancy Pelosi’s visit to Taiwan. Climate experts say Xie and Kerry were able to draw on their personal ties to resume work despite the timeout — and that could be a buffer against future friction.

Environmental advocates insist climate progress between the US and China can’t rest solely on the two men’s shoulders. “The relationship obviously has to extend beyond them,” said David Waskow, director of the World Resources Institute’s international climate initiative. “It can’t just be based on them.”

Yet for now, it may be vital.

“In the conduct of foreign diplomacy, relationships are super important,” Kerry said. “We trust each other.”

Author: Jennifer A. Dlouhy