John McCain will take the stage in Ottawa on Friday to try to draw a clear line between himself and Barack Obama on the North American Free Trade Agreement (NAFTA). You'll remember that Obama and Clinton mixed it up during the primary race about who would go further in renegotiating the trade deal to strengthen labour and environmental standards. McCain, by contrast, wants to portray himself as a free trader, no holds barred.

It's a surprise in itself that a U.S. presidential candidate would give a campaign speech on foreign soil. Given the large Latino population in America, McCain could have chosen to give the speech in Mexico, but that would have invited stories about U.S. factories relocating there at a time when the U.S. economy is flirting with recession.

Instead McCain gets to point to what some Americans would see as a key benefit to them under NAFTA -- access to the second largest petroleum reserves on the planet in the Canadian tar sands. The trade deal effectively prohibits Canada from treating its oil as a national resource, instead letting the market dictate who gets to play and who gets the oil. In practice, this means American oil companies get to play freely and the U.S. also gets most of the oil.

Indeed, McCain has been stumping on the issue of energy security for the past several days, even reversing himself on the issue of offshore drilling in the U.S. to play to the concern over high gas prices. He seems to be gambling that anger at the pump will trump strong feelings against offshore drilling in key election battlegrounds like Florida.

Contradicting himself on global warming?

McCain is also walking a tightrope on global warming. He is running ads highlighting his break with the Bush administration on wanting to address global warming, which is where things get interesting with regards to the Canadian tar sands.

While giving money to friendly Canadians for oil may seem more attractive than giving it to some regimes in the Middle East, the problem is that extracting oil from the Canadian tar sands comes at a huge environmental cost. The deposit is wrapped in clay and sand, so a massive amount of energy is needed to get the oil out, whether by using the largest machines on the planet or by using huge amounts of natural gas.

The impacts of extraction include extensive landscape scarring, the dumping every day of 1.8 billion litres (480 million gallons) of toxic tailings into artificial lakes now so large you can see them from space, air pollution creating acid rain across the prairies, and a huge global warming problem.

Producing a barrel of tar sands oil gives off three times the greenhouse gas emissions as producing a barrel of regular oil, making the tar sands the fastest growing source of new emissions in Canada and the main reason politicians in Ottawa are refusing to meet their international commitments on global warming.

The bottom line is that looking to the tar sands to guarantee U.S. energy security puts candidates on a collision course with their commitments to tackle global warming. And, as a blue-ribbon panel of retired U.S. military leaders has pointed out, global warming itself threatens to disrupt global stability, thereby undermining energy security. In this regard, the tar sands are a false promise.

Towards a less oily relationship

What's to be done? As with any trading relationship, Canadians and Americans both share some responsibility in this equation. There are huge gains to be made in U.S. vehicle efficiency that is both the cheapest plank in the energy security platform and a way to substantially reduce U.S. emissions. There is, in fact, an economic revolution waiting to happen to retool the U.S. economy and put it on a low carbon footing.

Canada meanwhile needs to figure out whether there is a responsible way to exploit the tar sands that does not jeopardize the world's climate nor leave behind a massive toxic mess for future generations to clean up after the party is over. Carbon capture and storage may be a part of this equation, but so far Canadian politicians are not talking about this at the scale and timeline necessary to be useful.

Politicians will come and go but the U.S. and Canada will continue to share the world's largest unguarded border and to trade peacefully. We have a common interest in ensuring this trade is environmentally sustainable, since this is the true foundation of security.

Related Tyee stories:

• It's the Tar Sands, Stupid
  Canada home to global warming's new ground zero.
• Oil May Be Canada's Undoing
  Political pressure bubbles and flows.
• The Plan to Disappear Canada
  'Deep integration' with US comes out of shadows.