President Obama has vetoed a bill to approve construction of the controversial Keystone XL pipeline, which would bring tar sands oil from Canada down to Texas refineries on the Gulf coast.

It’s important to note that the pipeline bill has been vetoed, not the pipeline.

For starters, pretty much everyone has noted that Keystone is not dead. All the veto means is that Congress isn’t able to force the pipeline’s construction through legislation — the process is just going back to being centered on the State Department’s administrative review procedure, as it largely has been for the last six years.

The State Department will consider the proposal and in their own good time make a recommendation to John Kerry as Secretary of State.

The bill was a political Tea party move to pre-empt State Department approval.

Meanwhile important court proceedings are taking place in Nebraska and South Dakota. The pipeline authority TransCanada is claiming ’eminent domain’ giving then the right to drive the pipeline through properties. About 90 Nebraska landowners claim that state law giving TransCanada the right to seize land under eminent domain is unconstitutional.

If the landowners succeed TransCanada does not have a route for the pipeline.

At Climate Central we learn that

the energy required to process tar sands oil is so great that oil piped through the Keystone XL will emit 1.3 billion more tons of greenhouse gas emissions over the pipeline’s 50-year lifespan than if it were carrying conventional crude oil.

President Obama has said he would only approve Keystone XL if it didn’t significantly increase carbon emissions. To me that makes the decision quite straightforward, but the argument is being put that the tar sands will be developed anyway, so the pipeline makes no difference.

Obama has said also that there is no need for the US to use oil from tar sands. Apparently energy security is a factor in his thinking.

A new study suggests that the majority of the oil will be used in the US.

My guess is that Obama does not want a tar sands pipeline approval as part of his legacy.