One of Canada's largest environmental organizations wants a multinational energy giant to focus on building a natural gas pipeline from Alaska instead of down Canada's Mackenzie Valley.
In a letter to the CEO of Exxon Mobil, the Sierra Club says the Mackenzie project would create more environmental damage and greenhouse gas emissions.
"The Alaska pipeline would be much longer than the Mackenzie Valley pipelines and carry three times as much gas, but is likely to cause less ecological damage," says the letter to Lee Raymond.
"It may be the lesser environmental evil."
The letter, signed by club directors Elizabeth May and Carl Pope, says the Mackenzie route includes much more intact forest and tundra.
"The Mackenzie pipelines ... would cause greater ecological fragmentation, not to mention harm caused by induced development along the pipeline route."
The club also points out that while the Alaska pipeline would supply gas directly to the U.S. market for heating and power generation, the Mackenzie route is expected to power Alberta's oil sands.
"Alaska gas could conceivably serve to reduce North American greenhouse gas emissions by displacing the use of coal and oil, whereas Mackenzie gas used to produce tar sands oil would result in large increases in Canada's greenhouse gas emissions," it says.
But Imperial Oil spokesman Pius Rolheiser said both pipelines would feed into Alberta's network, making it impossible to specify the destination of gas from either project.
"The oft-repeated piece of information that states that all of the (Mackenzie) gas would go to serve the oil sands is a red herring," he said.
As well, Brendan Bell, industry minister for the Northwest Territories, points out there already is a pipeline right-of-way along the Mackenzie Valley as far north as Norman Wells.
The letter adds that Exxon's Canadian subsidiary, chief pipeline proponent Imperial Oil, has been "singularly inept" in studying environmental effects.
It also suggests legal complications for Mackenzie.
"You and your shareholders should not discount the potential for litigation in Canada, which could result in project delays and additional costs," the letter says.
Rolheiser responded that after initial problems, Imperial's environmental work has now been approved by the project's review panel.
Stephen Hazell of the Sierra Club maintains that despite the Norman Wells line, much of the proposed Mackenzie route is still untouched forest.
He's skeptical of claims there's no connection between oil sands development and the Mackenzie pipeline.
"The evidence we have is that Mackenzie gas is going to Fort McMurray ... while Alaska gas is really going to feed a southern market.
"We want to do what's right for the atmosphere, and what's right for the atmosphere is to use natural gas to replace oil and coal."
Exxon Mobil is involved in two proposed pipelines, one from Alaska's north slope down the Alaska Highway and the other along Canada's Mackenzie Valley. Analysts have long suggested that there isn't enough money, labor and steel to build both at the same time, and that the second-place project would be delayed for a generation.
Provincial, state and territorial governments have all been lobbying hard to maximize benefits for their own jurisdictions.
Bell says his government believes that both projects will be needed.
He said the Mackenzie project is too small to delay the Alaska pipeline. But if the Alaska project went first, that could stall the Mackenzie proposal.