This whole issue seems to be a perfect example of environmentalists (and I consider myself one), letting the perfect be the enemy of the good, or in this case the better than the alternative. Yes, tar sands is dirty oil. Yes, extracting it has terrible environmental costs (its right up there with coal mining). However, unless oil prices take a big dive, they are going to do it anyway. So the question is how that oil will be transported to refineries. So basically we have 2 choices: rail or pipeline. Transporting that oil by rail greatly increases the odds of a spill and it results in higher emissions. So being that they are going to extract that tar sands oil anyway, why would we not want to transport it by pipeline rather than rail being its the lesser of 2 evils?
"You're the only person that decides how far you'll go and what you're capable of." - Ben Saunders (Explorer and Endurance Athlete)