For the last five or six years, there's been a big mystery in climate science: What's behind the sudden rise in global ethane gas emissions?

Ethane is a hydrocarbon (a gas made of hydrogen and carbon) and is the second most common one in the atmosphere.


A simulation showing surface ozone levels over the U.S. GIF via Michigan Engineering/YouTube.

One of the main sources of ethane is the process of drilling for fossil fuels. When ethane enters the atmosphere, it can react with sunlight and other molecules to form ozone, which is a greenhouse gas.

Ethane emissions were steadily decreasing until about 2009, when they started to crawl back up again — and no one could really explain why.

Scientists had their suspicions, though: One thing that seemed to coincide with the rise in ethane emissions was a rise in shale oil and gas production in the U.S. using a process called hydraulic fracturing.

A hydraulic fracturing site in Pennsylvania. Photo by Spencer Platt/Getty Images.

Hydraulic fracturing (referred to as "fracking") is a controversial process wherein drills inject fluid into underground shale formations in order to fracture them and release their oil.

Fracking is already responsible for water contamination, according to a report by the EPA, and releasing toxic chemicals into the air, which can cause health problems for those living nearby.

Photo by Andrew Burton/Getty Images.

Ethane emission is just one more thing added to the list of dangerous consequences of fracking.

A massive amount of these ethane emissions are coming from a single (huge) place called the Bakken Formation.

Stretching across parts of North Dakota, Montana, Saskatchewan, and Manitoba, the Bakken Formation is a massive oil and gas field that contains many pockets of oil thousands of feet below the surface.

Sections of pipe waiting to be welded together in North Dakota. Photo by Andrew Burton/Getty Images.

So how much ethane are we talking about?

Oil production at the Bakken Formation jumped by a factor of 350 between 2005 and 2014, and with that rise came a rise in ethane emissions.

At the Bakken Formation alone, about 250,000 tons of ethane are produced per year. Which accounts for 2% of the total ethane globally.

"Two percent might not sound like a lot," Eric Kort, assistant professor of climate and space sciences at the University of Michigan, told ScienceDaily, but the emissions in the Bakken Formation are "10 to 100 times larger than reported in inventories" and they "directly impact air quality across North America."

A worker on an oil rig in North Dakota's Bakken region. Photo by Andrew Burton/Getty Images.

Ethane emissions on this scale are harmful in many ways.

Besides the greenhouse-warming effect they can have on our planet, they're also a surface-level air pollutant.

In fact, they're one of the pollutants the national Air Quality Index measures when it wants to let people know that breathing outside for extended periods of time could be harmful.

Rural North Dakota, which sits atop the Bakken formation. Photo by Andrew Burton/Getty Images.

Ethane also forms ozone on the surface. Ozone up in the stratosphere is good because it protects us from the sun's ultraviolet rays. But when it forms on the surface and is breathed in by people, it can cause lung damage, worsen asthma and emphysema, and even damage ecosystems.

The fact that one region in the U.S. is poisoning the air on a massive scale should amaze you just as much as it scares you.

"These findings not only solve an atmospheric mystery — where that extra ethane was coming from — they also help us understand how regional activities sometimes have global impacts," said Colm Sweeney, a scientist with the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder.

We're all living in the same climate.

Actions on a regional level don't just affect us here in America or those living near the Bakken Formation, they affect the air people breathe the world over. If one area in the United States can suddenly start creating 2% of global air pollution, imagine what else increases in oil production can be capable of.

A kid living in the Bakken region. Photo by Andrew Burton/Getty Images.

On the other hand, if we can do that much damage in such a short amount of time, surely we can move quickly to do some good too.

Sure, putting an efficient lightbulb in your kitchen isn't going to save the world, but as we've seen, actions large and small, especially on a regional level, can have big impacts.

If we as individuals decide to start being energy efficient quickly and on a massive scale, the way oil companies decided to drill the Bakken Formation quickly on a massive scale, maybe companies would follow suit, and then, who knows what positive effects we'd see?