Pumping in dirty oil From Canada's tar sands

The State Department announced that it has okayed a new oil pipeline between Canada and the United States. A press release hails the decision to break ground on the Alberta Clipper Pipeline for sending "a positive economic signal, in a difficult economic period, about the future reliability and availability of a portion of United States' energy imports" and for providing "shovel-ready" jobs. What it doesn't mention is that the pipeline between Alberta and Wisconsin will be pumping oil from Canada's tar sands"some of the world's dirtiest petroleum.