Last week, the federal government temporarily blocked construction of the 1,134 miles

Dakota Access Pipeline (DAPL) which was supposed to carry 570,000 barrels of crude oil per day from the Dakotas to Illinois. The Standing Rock Sioux and other tribal nations claimed, with the support of environmentalist groups, that the pipeline would damage their environment and cultural sites. This decision is the result of a new kind of environmental activism that treats energy pipelines as a chokepoint for activities that contribute to global warming, and builds alliances with other groups to stop them.

Traditional tactics don’t work like they used to

Traditionally, activists have tried to lobby government to prevent energy firms from accessing new areas for oil, gas and coal, to regulate how they refine oil, extract coal, and generate electricity. They have sought tougher fuel efficiency standards and mandates for electricity companies to use of renewables in electricity generation. Sometimes they have lobbied customers, hoping that they will sanction firms for bad policies.

All of this is aimed at stopping or slowing down global warming — but it has had mixed success. Energy companies have often blocked or weakened regulatory action. It has often been hard to mobilize consumers, who are addicted to automobiles and energy intensive lifestyles, and believe that they have little power over markets.

That’s why environmental activists are targeting pipelines

Now, activists are trying something new — disrupting how the fossil fuel industry transports its products. Their objective is to prevent the fossil fuel industry from accessing the pipelines and railroad networks they need to move their products. The logic is simple; if products cannot be moved, they cannot be sold and will not contribute to global warming.

This “pipeline politics” does not ask governments to enact new regulations. Instead, it leverages the existing regulatory framework. Environmentalists have built coalitions with actors that are more interested in local issues than in global climate change. These actors fear that transportation of fossil fuels might contaminate their water resources, infringe on their fishing rights, or desecrate their sacred lands. Native American nations are an especially attractive ally, because they often have treaty rights over land and water use that the U.S. government is obliged to take account of.

Environmentalists are allying themselves with Native Americans

This explains the fight that is happening right now in North Dakota. It also explains why environmental groups have struck up alliances with Native American nations and tribal groups to disrupt the transportation of oil and coal elsewhere.

Take the case of the Gateway Pacific Terminal at Cherry Point, Washington. This was supposed to be the largest coal exporting facility on the West Coast, allowing the export of coal mined in the Power River Basin in Montana and Wyoming. Environmentalists collaborated with The Lummi Nation, which believed that the Cherry Point terminal would adversely impact its fishing investments (for reference, the Lummi nation owns the largest native commercial fishing fleet in the U.S.). Importantly, the Lummi Nation had leverage because it had signed a treaty with the federal government in 1855 that guaranteed its rights to fish in the Salish Sea.

In 2015, the Lummi Nation filed a petition with the Army Corps of Engineers claiming that the proposed terminal would damage its fishing and desecrate its sacred sites. This saw them opposing another Native American tribe, the Crow Nation in Eastern Montana, which partnered with Cloud Peak Energy to develop a coal mine on its land, but which did not have the advantage of a treaty. The Army Corps of Engineers ruled in favor of the Lummi Nation.

Similarly, in 2015, the Swinomish Indian Tribal Community sued BNSF in federal court to stop the transportation of Bakken crude oil through its lands. The Quinault Indian Nation, in collaboration with environmental groups, has successfully challenged the granting of a permit for the Grays Harbor Terminal as well as Imperium Bulk Liquid Terminal Facility in Hoquiam, both in Washington state.

The Keystone XL fight is really about Albertan tar sands

Pipeline politics also explains the enormous controversy over the Keystone XL pipeline, where environmentalists have made the running through the Department of State rather than alliance with Native Americans. This pipeline sought to transport crude oil extracted from Canadian tar sands to refineries in the U.S. Gulf Coast where it could be refined and exported overseas. Because the Keystone XL pipeline crosses international borders, it requires TransCanada, the parent company, to apply for regulatory permission from the U.S. Department of State.

There is no evidence that building a new oil pipeline would create a big new environmental problem in itself. After all, the United States already has the largest pipeline network in the world: 1.2 million miles for natural gas, and 150,000 miles for petroleum products. In comparison, the Keystone pipeline is only 1,700 miles long. Environmentalists are fighting Keystone because it will be far harder for oil companies to make use of the Alberta tar sands without the pipeline. Since these tar sands are among the largest oil reserves in the world, this could have a massive secondary impact on global warming.

This explains why environmental groups made the Keystone approval an important litmus test for the Obama administration’s commitment to climate change mitigation. Environmental activism also moved Democratic Presidential candidate Hillary Clinton from apparent support for the pipeline to claiming that “I never took a position on Keystone until I took a position on Keystone.”  The Obama administration’s rejection of TransCanada’s application for the pipeline was a victory for the environmentalists because less tar sand will be mined for oil, at least in the short run.

The coal industry is facing another challenge. Given that much of the coal is transported in open railways carriages, communities in the vicinity of railways tracks are exposed to coal dust and face respiratory problems.  Environmentalists are now working with local communities and public health activists to stop coal trains from using existing railway tracks that pass through densely populated areas.

Environmental activists — like other political actors — find it hard to get Congress and the executive branch to introduce new laws and regulations. Because the current system has many veto points, this has led them to think creatively about whether choke points elsewhere in the system can be exploited. The energy industry’s need for railroads and pipelines is one such choke point. If activists can band together with actors whom regulators need to take account of, or exert sufficient pressure in their own right, they can be very successful in stymieing the energy industry, and forcing it to take environmentalists’ concerns more seriously.

Nives Dolšak is professor in the School of Marine and Environmental Affairs at the University of Washington.

Aseem Prakash is the Walker Family Professor and the founding director of the Center for Environmental Politics at the University of Washington.

Maggie Allen is a graduate of the School of Marine and Environmental Affairs and works as a social scientist at the National Oceanic and Atmospheric Administration.