> But if it is "on the way out", what's the need for blocking the pipeline?
It's economics. Shipping by pipeline is cheaper per gallon than shipping by rail/truck/ships. Even accounting for the huge capital costs to build the pipeline in the first place, once a pipeline is secured the marginal costs of shipping additional gallons is so much lower there would be more prices at which it would be profitable to extract tar sands oil versus if the tar sands extractors have to also account for the increased marginal costs of rail/truck/ships.
Tar sands extraction has already seen mass stoppages when the Saudis flooded the supply chain with oil and dropped the oil costs below what was profitable. (Tar sands extraction is worse for the environment than classic oil drilling and thankfully at least some [though never enough] of those externalities are at play in its costs versus oil drilling.)
Right now the price is up again and tar sands work probably is going back into place and it probably will still be shipped by rail/truck/ship. So the short term problem is the same.
But stopping a pipeline today keeps the pipeline from being a fully depreciated asset for oil sands five/ten/fifteen years from now when the supply/demand curve potentially invert and oil is super cheap again (because demand is way down). The higher marginal costs on shipping especially matter then, because potentially it stops tar sands extraction from again being profitable in far more frightening high supply/low demand periods. In that case it should mean less supply gets put onto the market, especially from high cost extraction techniques such as tar sands.
It's economics. Shipping by pipeline is cheaper per gallon than shipping by rail/truck/ships. Even accounting for the huge capital costs to build the pipeline in the first place, once a pipeline is secured the marginal costs of shipping additional gallons is so much lower there would be more prices at which it would be profitable to extract tar sands oil versus if the tar sands extractors have to also account for the increased marginal costs of rail/truck/ships.
Tar sands extraction has already seen mass stoppages when the Saudis flooded the supply chain with oil and dropped the oil costs below what was profitable. (Tar sands extraction is worse for the environment than classic oil drilling and thankfully at least some [though never enough] of those externalities are at play in its costs versus oil drilling.)
Right now the price is up again and tar sands work probably is going back into place and it probably will still be shipped by rail/truck/ship. So the short term problem is the same.
But stopping a pipeline today keeps the pipeline from being a fully depreciated asset for oil sands five/ten/fifteen years from now when the supply/demand curve potentially invert and oil is super cheap again (because demand is way down). The higher marginal costs on shipping especially matter then, because potentially it stops tar sands extraction from again being profitable in far more frightening high supply/low demand periods. In that case it should mean less supply gets put onto the market, especially from high cost extraction techniques such as tar sands.