President Donald Trump signed a number of executive orders Tuesday to advance construction of the Keystone XL Pipeline and Dakota Access Pipeline.
Activists had previously successfully fought both pipelines — the protest at Standing Rock, which was led by the Native American community, made headlines in 2016.
The Keystone XL Pipeline is slightly older news — Obama blocked its construction in 2015 — but it's worth remembering why it made environmentalists so worried.
What is the Keystone XL Pipeline?
The Keystone XL Pipeline would carry Canadian tar sand oil 875 miles from Morgan, Montana to Steele City, Nebraska.
Built by TransCanada, it would allow the company to move its raw product from tar sand extraction sites in Alberta, Canada to refineries in Texas.
Tar sand oil is the dirtiest fossil fuel on the planet
Tar sand oil does not sit in a cavern underground, waiting for someone to stick a long straw in and suck it up. Instead, the oil is mixed up with the dirt in Alberta's boreal forest (underneath a bunch of trees) which makes extracting it very difficult.
In order to retrieve all that oil, Alberta's oil companies strip away the local forest then dig the sand out of the ground. But the clumpy, sandy mixture would constipate an 875-mile pipeline, so the companies mix it with water diverted from the Athabasca river. Each barrel of bitumen (that's the technical term for the tar sand) gets soaked in 2.4 barrels of water.
Once it's used, that water is too poisonous to return to the river, so adds up to billions of gallons of waste. The contaminated liquid ends up sitting in "tailing ponds," where it leaks into the local environment and increases the rate of cancer among people who live nearby.
Meanwhile, the Athabasca River only has so much water to offer, and there's a real threat that the oil sand mines will use it all up.
The climate risk is severe
The biggest problem with tar sand is also the reason people who make money from the fossil fuel industry love it: There's a lot it.
If companies extract all the oil that today's technology allows them to, burning it would add 22 billion metric tons of carbon to the atmosphere. If technology improves to the point where companies can extract every drop of oil bound up in bitumen, that total would increase to 240 billion. The Alberta tar sand project alone could lead to a global temperature increase of 0.4 degrees Celsius.
Tar sand spills are harder to clean up
Oil pipeline spills are bad, and they happen all the time. They poison drinking water, pollute farmland (which in turn kills farming jobs), and wreck local environments.
But tar sand pipeline spills are worse.
To pump tar sand crude along a pipeline, extractors mix in natural gas liquids to act as a kind of crude laxative.
In 2010, that bitumen-natural gas mixture spilled from a Canadian-owned pipeline into the Kalamazoo River in Michigan. The liquefied natural gas turned to gas and blew through nearby neighborhood, forcing residents to evacuate. The bitumen sank to the bottom of the river, poisoning 40 miles of water and 4,435 acres of coastline. Five years and $1.2 billion later, it still hadn't been cleaned up.
Even if everything goes as planned, there will still be environmental impacts
Tar sand extraction and refinement is a dirty process, even when there are no spills. In addition to the poisonous water sitting in Alberta, the refinement process produces a black dusty substance called "petcoke." That petcoke piles up in places like Southeast Chicago, waiting to be burned as a cheaper, less efficient coal substitute. And on windy days, those piles get blown around, coating anything nearby in black dust.
If the Keystone XL Pipeline does get built, it will fall to the Environmental Protection Agency (EPA) to protect Americans from all of these risks. At the moment, however, the EPA isn't issuing any new grants or contracts, and is not responding to inquiries from the press.
SEE ALSO: The EPA, which protects Americans from poison and pollution, has been frozen under Trump
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