The concept of national sovereignty has always carried considerable emotional freight. National pride, a shared sense of history and identity, and common values and priorities have played an important role in reinforcing physical borders and boundaries.

In a global age when technology and trade have diminished those traditional barriers between countries, the emotional quotient of sovereignty has increased exponentially. People may intellectually understand reality in this expansive new context, but the inherent shift in control is, at the same time, deeply unsettling.

For governments, that presents a challenging dual track: multilateral agreements and alliances are essential but, at the same time, the domestic agenda and strategic national interests have to be protected " and be perceived to be protected.

The catch, of course, is that it can be difficult to know if a successful balance between domestic and international interests has been achieved until some time in the future. In the case of the Acid Rain Accord, for example, the full extent of the accomplishment has taken 20 years to materialize.

For Canadians, who are accustomed to navigating a relationship with a large and powerful neighbour to the south, this balancing act isn’t new. But the increased urgency around emerging environmental files such as climate change has added a new dimension.

The reality, of course, is that no environmental strategy can be purely national. Air, water, wildlife and other elements of the earth’s ecosystem are impervious to lines drawn on a map. In the case of the United States and Canada, the shared continent is mirrored in an entwined economy.

Firms in many key sectors, such as automotive and aerospace, cooperate more than they compete as suppliers to and customers of each other in complex, cross-border supply chains.

On the energy front, we comanage and co-own pipelines and power grids that transcend the 49th parallel. Through our membership in the North American Electricity Reliability Corporation (NERC), Canada is committed to maintaining a reliable source of continental power 24/7.

Through the International Energy Program, forged in 1974 and reaffirmed through NAFTA, we agreed to share oil with the United States in times of emergency, short supply and energy insecurity.

Nevertheless, because environmental policy is so important to the domestic agenda, continental harmonization requires that Canadian interests be fully considered and reflected in any collaborative initiative.

But it goes beyond our environmental, economic and energy interdependence to another compellingly practical consideration: we all know it’s going to be a great challenge to stabilize greenhouse gas emissions in the atmosphere at nondangerous levels. The reality is that success is best realized with the full cooperation of the United States and all other major emitters.

If Canada does more to reduce GHGs than the US, we will suffer economic pain for minimal environmental gain. And that economic pain could impede our ability to invest in clean energy technology and other long-term solutions.

If, however, we do less than the United States, we face the risk of new barriers to entry in an export market upon which we rely heavily.

That means that we need a substantial environmental effort from the US and a comparable effort from Canada that creates a North American climate change regime with national policies that are harmonized, consistent and free from conflict.

A continental system based on policies and regulations that are equal in value and have a similar effect is the best way to foster fair competition and to maintain free trade in an integrated North American market.

These policies by no means need to be identical. Rather, they need to achieve that delicate balance between international and domestic imperatives and take into account the nuance of our respective economies and societies.

Furthermore, this approach is consistent with past practice: Canada already has an established record of successful bilateral cooperation on environmental issues. For more than a century, we’ve sustained the CanadaUS Boundary Waters Treaty of 1909 and its International Joint Commission.

The most dramatic evidence of the success that results from alignment on environmental and health policy is the Canada-US Air Quality Agreement " better known as the Acid Rain Accord " which has been in place for 20 years this month.

Before the Acid Rain Accord was implemented, Canada’s total emissions of acid-rain-causing pollutants like sulphur dioxide were twice current levels. In vast areas like the Ohio River Valley, through the lower Great Lakes, the East Coast of the US and southern Quebec, the pollutants were more than three and a half times what was then considered the damage threshold.

To save species and habitats on both sides of the border, it was as clear then as it is now that there was no unilateral solution. Without close crossborder cooperation and agreement, neither side had a chance of addressing the problem.

By 2008, Canada had reduced its sulphur dioxide emissions by 47 percent from 1990 levels and the US had posted a 51 percent reduction from 1990 levels. Ecosystems affected by acid rain show measurable signs of improvement, as have health-related issues like asthma, bronchitis and other respiratory conditions.

It also became apparent that even more work was required and the Clean Air Agreement was used as a platform to build out an even more comprehensive initiative that covered the air pollutants that contribute to the creation of smog.

In 2000, the Ozone Annex was formally added to the existing Air Quality Agreement. Within eight years, Canada reduced related emissions by 32 percent and the US made cuts of 33 percent. That’s also formed the basis for ongoing collaborative scientific study, and other annexes to the Agreement are in the works.

As the urgency of addressing GHG emissions and climate change has gathered momentum, this template has been used to address one of the major sources of harmful emission: transportation.

Canada and the United States have worked closely to craft new emission standards for passenger vehicles and heavy trucks. Given the size of the problem and the integrated, continental scale of the automotive sector, it makes sense to align our regulations.

We’ve also created other platforms for the exchange of information and initiative, specifically the Clean Energy Dialogue between President Barack Obama and Prime Minister Stephen Harper. The future will bring other environmental files where it makes sense to harmonize our respective policies and regulations.
That is just one of the many strategies that must be deployed for Canada to achieve the GHG reduction targets to which it has committed under the Copenhagen Accord. We may share targets, but Canada and the US also have some fundamental differences that have to be accommodated.

In the case of electric power generation, for example, it does not make sense to take a shared approach because our respective energy profiles are radically different. While Canada has an abundance of clean hydroelectric power, the US remains more reliant on coal. That’s why we’ve struck out on our own to develop a policy framework that’s relevant to Canada’s unique profile.

In addressing climate change Canada is also adapting the same successful approach used to develop and implement the Air Quality Agreement. We are systematically working on a sector-by-sector basis to regulate and reduce emissions.

A great deal has changed in the past 20 years for Canada and the US, but one thing has remained constant: we do our best work at protecting our shared ecosystem when we do it together.