The more than 30 countries gathering in Montreal this weekend to reaffirm their commitment to the Paris agreement and work on the detailed rulebook for implementing the global deal are sending a “signal to the international community that the world’s major economies aren’t backing away from the climate fight,” Pembina Institute Federal Policy Director Erin Flanagan suggests in a blog post this week.

The meeting, convened by Environment and Climate Minister Catherine McKenna and her counterparts from China and the European Union, takes place just two months before the UN climate conference in Bonn November 6-17. Which makes it “hugely encouraging that these major economies are coming together [in Montreal] to sustain global momentum on mitigating the most damaging impacts of climate change,” Flanagan writes.

“This signal is important to future progress, since the international community still has its work cut out for it to fully implement the Paris agreement,” she notes. Though the agreement entered into force last November 4, four years ahead of schedule, the nuts and bolts of Paris implementation are still taking shape, and very much in need of discussion.

The other (narcissistically misshapen) shadow looming over the meeting is Donald Trump’s decision to withdraw the United States from the landmark global deal. Although the pullout won’t take effect until November 2020—ironically, the after the next U.S. federal election—there is still concern that the current administration will obstruct Paris implementation at every turn.

But Flanagan notes the U.S. will be sending a representative (apparently not climate-denying EPA Administrator Scott Pruitt) to the Montreal session, and McKenna is scheduled to meet White House economic advisor Gary Cohn in New York next week. “It appears that the next two weeks will provide tremendous insight into how the Trump administration will engage on climate issues,” she writes. And earlier this week, McKenna said there’s still time to convince the U.S. not to leave the Paris deal.

But “no matter where the U.S. lands on its approach to reducing carbon pollution,” Flanagan stresses, “now is the time for all major economies to focus on concrete actions to reduce emissions and achieve their Nationally Determined Contributions. The true test for Paris compliance is whether or not domestic policies align with the ambition of the agreement.”

While there’s still a 44-megatonne “ambition gap” between Canada’s carbon plan and its Harper-era carbon target for 2030, Flanagan notes that “implementing the Paris agreement will unlock transformative change in our economy. To some that might sound scary, but the good news is that a decarbonized world will bring an improved standard of living, more climate-resilient infrastructure, and serious economic benefits. We all stand to gain from global action on climate change.”

And “increasingly, countries without progressive environmental policies will be left behind as the world decarbonizes to avert the most dangerous impacts of climate change.”