SAINT-SAUVEUR, QUEBEC -- The recent Glasgow conference and this week’s “Three Amigos” meeting in Washington will provide an opportunity for Canada to fulfill its early promise to play a leading role on climate change.

“Canada is back, my goods friends”! That was the wishful boast of Justin Trudeau as he spoke at the Paris Climate Conference shortly after being elected in 2015.

The reality turned out to be trickier than that.

When Trudeau returned to Canada he discreetly announced that he’d be holding onto Stephen Harper’s targets and timelines and we never even met those.

NAFTA was the first major international trade deal to tackle the complex issue of the environment. American legislators were justifiably concerned that manufacturing jobs would be shipped South to Mexico where lax environmental rules would make it cheaper for many to operate.

A parallel environmental agreement was signed and a Commission for Environmental Cooperation, headquartered in Canada, was created. Overall, it’s been a success.

Joe Biden also made major environmental promises when he was running for president a year ago. His plan, presented in great detail, provided for new rules to tax “free riders” at the border.

Countries that refused to meet their international obligations to reduce greenhouse gases would find financial penalties attached to their exports. If American companies were henceforth going to have to internalize those environmental costs, everybody would be expected to. It was pay now or pay later. But everyone would pay.

Once again, reality turned out to be trickier than theory.

During Biden’s first year in office, as the pandemic wound down and the economy ramped up, the U.S. burned 100 million more tons of coal than during Trump’s final year. A spectacular and dangerous failure.

Canada’s 2021 numbers (not officially available for another two years) will in all likelihood be similarly disappointing, for the same reason, although we burn far less coal, per capita.

There’s nothing new in the idea of punishing scofflaws who don’t follow international environmental rules. In the early days of the Kyoto Protocol, then French Prime Minister Dominique de Villepin had realized the economic folly of respecting international rules when your trading partners don’t. He simply said it was necessary to tax the countries that didn’t respect that agreement.

It’s taken quite a few years to get there, but Trudeau’s statement in Glasgow that all countries should have a carbon levy similar to Canada’s has brought de Villepin’s notion back to the forefront. It is now understood and beginning to be accepted.

If another country is producing aluminum or steel using electricity produced by burning coal, without regard for their international obligations, your country should be allowed to level the playing field by making the polluter pay. Dirty steel or aluminum should not be protected by international trade rules. It should be taxed and thus discouraged. Countries whose manufacturers incur the costs of respecting the rules are entitled to see those costs imposed on outliers.

That’s where the “Three Amigos” come in.

Nobel prize winning economist William Nordhaus uses the shorthand expression “climate clubs” to describe agreements where jurisdictions come together with rules to reduce greenhouse gases by rewarding, or penalizing, good or bad results. The Western Climate Initiative between California and Quebec is a good example.

Given our lengthy experience dealing with each other and the fact that the environment has been part of our trilateral trade relationship since the beginning, it would be natural for Canada, Mexico and the United States to show the way and become the most important “climate club.”

As was the case with international free trade agreements, other jurisdictions would have an incentive to follow suit and begin enforcing environmental norms at the border.

There’s been a lot of debate as to whether Glasgow was, overall, a success or a failure.

I believe it was a success.

For the first time, nobody was even trying to question the science. That battle appears to have been won. Climate change in general and global warming in particular are caused by human activity. Failure to act by reducing greenhouse gases will have a devastating effect on ecosystems, biodiversity and, ultimately, human life.

That’s the easy part. Now the real hard part begins.

When India balked at signing an agreement that spoke of “phasing out” coal, arguing instead for “phasing down,” many saw it as capitulation. I see it as refreshing honesty. Unlike Paris where everyone signed on the dotted line, gave high fives, went home and…did nothing, Glasgow is real.

India knew it didn’t yet have the manufacturing depth or economic resilience of China, to rapidly bring in green, renewable replacements for coal. It was simply telling the truth.

Emerging economies can and should get support from those countries whose advanced industries have been polluting the planet for far longer. Reducing their greenhouse gases, however, is an obligation, not an option.

Glasgow was a turning point for Canada on the world stage. The superb performance of new Environment Minister Stephen Guilbeault, who is highly respected internationally, reflected well on us and on Trudeau.

We now have a chance to play a role we haven’t been used to since the early '70s when John Turner and Pierre Trudeau took a “sustainable development” approach internationally, long before the term was coined.

Precisely because we are such an important energy producer, Canada’s ability to prove that it can be done will help force the hand of other laggards, like Australia. The planet, and future generations, will be the beneficiaries.

Tom Mulcair was the former leader of the federal New Democratic Party of Canada between 2012 and 2017.