By ROBERT REDFORD – TheGlobeandMail.com

Working in Vancouver for the past several months has allowed me to spend fall in one of the most spectacular cities in the world, amid the natural splendour and wilderness wonder of British Columbia.

It’s been a reminder to me of the close partnership Canadians and Americans have forged as neighbours, bound by geography, history and culture reaching back to our national beginnings. Over the generations, these bonds of common experience and identity have combined to create something even more important: the values we share around the need to stand up for the lands we treasure and love.

Today, together, we need to stand up once more, because the lands we treasure and love are imperilled by a threat we must meet as one.

In Alberta’s great boreal forest, one of the last truly wild places on Earth, tar-sands producers have turned an area the size of Chicago into an industrial wasteland and international disgrace.

Where spruce and fir and birch trees once rose and waters ran fresh and clean, tar-sands production has left a lifeless scar visible from outer space, a vast repository of enduring pollution that threatens fish, birds, animals, public health and an entire way of life for native people.

And for every single barrel of oil produced, at least two tons of tar sands are excavated and tapped, a processing nightmare that generates three times more carbon pollution than is released to produce conventional North American domestic crude.

Not only is tar-sands production laying waste to Canada’s forests, polluting waterways, air and land, but the resulting carbon emissions are threatening Canada’s long-time commitment to reducing the greenhouse gases that are warming our planet and threatening us all.

This is unsustainable. It doesn’t make any sense. It’s another shameful example, frankly, of the oil industry doing whatever it takes to make a profit and leaving it for the rest of us to bear the costs and put up with the mess.

I want to be very clear that I’m not pointing a finger at the people of Canada; neither is any American I know. We’re all in this together, and that’s the only way we’ll turn it around. We need to stand up, Canadians and Americans as one, to draw the line at tar sands.

The United States is the largest consumer of oil in the world. Americans are a big part of what’s driving this scourge. That means we need to do more to reduce our demand.

Our oil consumption is down about 9 per cent since 2005. That’s a good start, but we need to do more. We’re pushing for cars that get better gas mileage, more efficient workplaces and homes. We’re investing in wind, solar and other forms of renewable energy. And we’re developing communities that give us more choice in how we live, shop and go to work.

Big Oil is fighting us every step of the way. In Washington alone, the oil and gas industry has spent more than $400-million over just the past three years lobbying our elected officials.

They’ve put enormous pressure on President Barack Obama to support tar-sands production by approving the Keystone XL pipeline, which would carry tar-sands crude from Alberta to refineries and ports along the Gulf of Mexico.

Instead of caving in to the lobbyists, Mr. Obama stood up and put on the brakes. He wants to make sure his administration takes the time for a thorough review. Those of us who care about our future are using that time to let him know this is a bad idea that needs to be stopped.

The same is true, by the way, of the Northern Gateway pipeline being proposed to move Alberta tar sands crude to Canada’s west coast for export by tanker. Crossing the territories of more than 50 first nations groups, slicing through rivers and streams that form one of the most important salmon habitats in the world and putting at risk the coastal ecosystem of British Columbia? Americans don’t want to see that happen any more than Canadians do, and we’ll stand by you to fight it.

“O Canada, our home and native land,” Canadians sing in the national anthem. “The True North strong and free!” Like so many other Americans, I’ve looked northward much of my life and found inspiration here.

We’ve found it in the wealth of creativity and talent showcased each year at the Toronto International Film Festival, the steadfast commitment of a devoted ally and the political conscience of a people determined above all else to honour and defend perhaps the richest storehouse of natural resources of any country in the world.

Now we’re looking to Canada once again, and searching for True North.

We need Canadians everywhere to join us in this fight. We need to call on the history and values we share and stand up, Canadians and Americans as one. We need to draw the line at tar sands. We need to reject the Keystone XL.

During four decades of environmental advocacy, actor and filmmaker Robert Redford has received numerous honours, including the United Nations Global 500 award.