From the Arctic islands to the Yucatan Peninsula, North Americans are increasingly concerned about the impacts of climate change, and rightly so. They understand the need to act. Their leaders, Prime Minister Justin Trudeau and presidents Enrique Peña Nieto and Barack Obama – the “Three Amigos” – understand it, too. Presenting a joint strategy to address the serious climate challenge was thus of prime importance at last month’s North American Leaders’ Summit in Ottawa.

The Amigos produced a plan, but did it go far enough?

Their timing was startlingly a propos, because this year, only half over, has already become the annus horribilis of climatic extremes. It’s been exceptionally hot: NASA recently reported that every month in 2016 up to the end of June was the warmest globally since good thermometer records first began to be collected and averaged over 130 years ago. But changes in average global temperature don’t tell the whole story, because the intense warming that the planet is experiencing is disproportionately much higher in the North, and this has particular implications that ripple across all of North America, not just the high latitudes.

What’s happening in the Arctic is pulling a trigger on climatic extremes: The region is warming at a rate some three times the global average, with profound consequences. A sunlight-reflecting mirror of ice used to cover much of the Arctic Ocean for most of the year, shrinking by somewhat less than half between late spring and late summer. But in 2012, 2015 and already again this year, it has shrunk by nearly three-quarters. By late June, when the Amigos sat down together in Ottawa, ice cover at the top of the world had retreated to the lowest areal extent for June since satellite monitoring began in 1981.

That should shock, for an Arctic Ocean that is no longer white and reflective in the 24-hour light of summer is now absorbing more and more photons from the sun. That’s amplifying the heating of the North, reinforcing global warming that is largely being driven by emissions of carbon dioxide from the populated South. And in that amplification lies a physical feedback that may already be rocking climate across the full north–south expanse of North America. Noted Rutgers University climate scientist Jennifer Francis has in recent years proposed that global warming and the retreat of Arctic sea ice have led to a reduced temperature contrast between the temperate regions and the North Pole. That in turn, she suggests, has changed the character of the Jet Stream, slowing it down and allowing it to wander farther to the north and the south, fueling climate extremes by allowing weather fronts to stall. Under such conditions, heat waves last longer, exacerbating droughts such as the four-year-long dry spell that is still afflicting California. And because fronts move more slowly, they spawn persistent intense deluges – and often, associated flooding – when warm, moist southern air butts up against colder, drier northern air masses.

We’ve seen such deluges repeatedly in Canada in recent years, in Toronto and Calgary in 2013, and in Dawson Creek, British Columbia, and Estevan, Saskatchewan, in recent weeks. And in April and again in May this year, southern Texas was hammered by record one- or two-day rainfall episodes that shattered previous records and flooded large swathes of the Lone Star State near Houston. There is growing statistical evidence that both the frequency and intensity of such events are increasing across the northern hemisphere, and to date they have caused billions of dollars of damage.

Thus, the retreat of sea ice in the far north might be contributing to flooding in the North American south and concurrent drought in the North American southwest, at least in part due to a behavioral evolution of the Jet Stream.

On top of all that, changes in the Jet Stream are now being implicated as being behind dramatic increases in ice loss from Greenland, which now sheds some 250 billion tonnes (275 billion tons) of ice per year. That’s adding to the sea-level rise that is threatening Charlottetown, North Carolina and Miami and low-lying areas along the Mexican coast.

In other words, what’s happening in the Arctic is not staying in the Arctic, at least in climatic terms.

It is against that evolving backdrop that the Amigos sat down to formulate a trilateral climate action strategy. They made some progress. A key output from their summit is the new “North American Climate, Clean Energy, and Environment Partnership Action Plan” that recognizes the immense scale of the challenge – not something seen in political opposition quarters across the three countries – while mapping out both aspirations and realistic steps that should lead to greenhouse-gas emission reductions and improved trilateral environmental stewardship. Most importantly, the new plan commits the three countries to produce half of their collective electricity supply by 2025 from non-emitting sources, including renewable energy, nuclear power, efficiency gains and application of carbon capture and storage technologies. While that target represents a one-third increase in clean-power generation across the three countries in just nine years, a goal described as aggressive by some, it should be achievable if the right policies are put in place.

Many such policies can best be described as just plain common sense. They include:

• cooperating across borders to integrate electrical grids so that clean baseload power in one jurisdiction, like Canadian hydropower, can be used to support intermittent renewable generation elsewhere;
• aligning efficiency and performance standards across North America;
• adding more renewables to the power grid on a continent-wide basis;
• collaborating on initiatives to encourage cleaner transportation, including continent-wide refueling corridors for non-carbon-emitting vehicles;
• encouraging adoption in the built sector of advanced heating and cooling technologies;
• reducing trilateral methane emissions from the oil and gas sector by 40–45 percent by 2025, an implicit recognition that it’s not just carbon dioxide emissions that must be reduced; and
• by 2018, limiting black carbon emissions from new heavy-duty diesel vehicles, continent-wide, to near-zero levels.

All of these initiatives are smart and doable, and there are many others in the plan that fit that same bill. But, alas, one critically important initiative is missing. The Amigos failed to mention the need to put an accelerating price on carbon emissions, something British Columbia did successfully in 2008.

Indeed, the words “tax” and “price” are not to be found in the plan, and their absence is striking. Yes, such words are politically loaded and almost impossible to say out loud this election year in the United States, but they could have been included in appropriately nuanced terms. It would not, or should not, have been a stretch for the Amigos to add one more clause. It could have been included under the heading “Showing Global Leadership in Addressing Climate Change,” and said something like, “Commit to work toward a continent-wide slowly accelerating price on carbon emissions that will take into account regional economic differences and the need to support those of limited means for whom such a price could present a hardship.”

The addition of that one clause would have spoken volumes. Without it, we are left with a plan that goes only partway toward what is needed. And that – in this year of climatic extremes that foreshadow the future – strikes this commentator as an opportunity lost.

The views expressed in this article belong to the author and may not reflect those of Arctic Deeply.

This article is produced in partnership with OpenCanada.org.

An earlier version of this op-ed indicated that the retreat of sea ice had led to a reduced temperature difference between the equatorial regions and the North Pole, instead of between the temperate regions and the North Pole.