Rivers of Oil podcast, Episode 1: Pipes

Pipelines are everywhere — 2.5 million miles of them — forming a web under our feet, our rivers, our roads.

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We've been building this web since the 1860s, and it's growing all the time. In the last decade we've added enough pipelines to wrap around the globe more than six times.

Pipeline companies once had little problem building lines when and where they needed. But it's not that easy anymore. Today, nearly every major pipeline proposal is met with protest, from Keystone XL to Dakota Access to Mountain Valley and Atlantic Sunrise.

Now, the battle over those pipelines — with all its costs and its chaos — looks to be headed for Minnesota.

Pipeline opponents are threatening to make northern Minnesota the next site of mass protest, if the state approves the Enbridge Energy company's Line 3 pipeline replacement project. Some opponents are already setting up camps, anticipating a fight. County sheriffs' offices are making plans for how to deal with potential protests.

Enbridge's proposal includes building a new pipeline that would increase the capacity of the current line, which has been in use since the 1960s. The new Line 3 would be able to transport oil from Canada's tar sands — and Enbridge would also like to build it along a different route than the current Line 3, which traverses Native American reservations in northern Minnesota.

But to understand how we got here, to understand why pipelines have become such a flashpoint, we need to take a step back: We wouldn't need all these pipelines if there weren't a whole lot of people consuming all the oil they transport.

On the first episode of MPR News' latest podcast, Rivers of Oil, we explore how society's appetite for oil has pushed us to find extraordinary ways to get more oil out of the ground — and how the pipelines carrying that oil have become a battleground in the war between our thirst for oil and the concern about the future of our planet.

Related reading

The history of the tar sands | Lots of news organizations have told the story of the tar sands in Alberta, Canada. The New York Times did it in 1975. Wired did it in 2004. The Washington Post did it the following year. The Calgary Herald and the CBC looked back at the area's oil industry at its half-century mark last year.

Getting oil from sand | The Atlantic ran a stunning series of photographs in 2014 by Reuters photographer Todd Korol, who documented the tar sands region's nature and industry, from high above and up close. And NPR offers a useful graphic explainer of how tar sands oil is extracted. And NASA's Earth Observatory has compiled a striking visual timeline of satellite images of the tar sands over the course of three decades.

Book: "The Patch" | Calgary journalist Chris Turner recently wrote the definitive book on the Canadian tar sands. It traces the history of the region from discovery to invention to boom — and in to the present-day humming of the Alberta oil industry.

Book: "Thirst for Power" | Michael Webber talked to us about our move toward newer sources of oil — like the tar sands of Alberta, Canada. That comes with an infrastructure cost, too, he said: "We need to do a replumbing of the national pipeline network for a couple of reasons. One, is we're producing in locations different than we were a few decades ago. Another is we're producing volumes that are different. And we're also consuming in different locations. So that means new pipes, bigger pipes, more directions, more places." Webber studies energy and energy policy at the University of Texas at Austin.

• Episode 4: The rallying cry
• Episode 3: The spark that ignited fires
• Episode 2: The largest inland spill