New research on cumulative ecological impact of oil and gas

Drilling has stripped bare three Yellowstones worth of land in recent years.


If you live in northwest New Mexico, northeast Colorado, Utah or Wyoming, or especially western North Dakota, you've probably noticed big changes in your local landscape of late. There are more roads, more traffic, more dust. There are more flares and bright lights piercing the night sky, and more trucks emblazoned with names like Halliburton. There are more pipelines and pump jacks. These are the things booming oil and gas communities live with so that we might all have cheaper natural gas and energy independence, that coveted and elusive prize.

The dust and traffic and lights aren't always easy to live with, and sometimes they create tension between local residents and industry. Rarely, however, do we stop to consider what all of this new infrastructure collectively costs us. How much vegetation is being lost to the boom nationwide, and how much does its loss matter? How fragmented is habitat becoming at a regional or continental scale? 

Brady Allred, an assistant professor of rangeland ecology at the University of Montana, had the seeds of such questions planted in his mind while living in Oklahoma a few years ago, doing research on plants, fire and grazing. Oil and gas wasn't new to Oklahoma, by any means, but new wells were popping up all over the place. Allred was struck by how much infrastructure and activity came with them. "The pad sizes were bigger, the amount of transportation, the amount of people that were needed," he recalls. "That's because of hydraulic fracturing and horizontal drilling. It requires a lot of space and equipment to get that done. You'd drive by at night and it looked like a little village out there, all lit up." He moved to Montana and visited neighboring North Dakota's gushing oil fields, and noticed the same things. "I thought, 'I wonder what it would be like if we zoomed out and looked at the bigger picture?' "

He and a few colleagues did just that for the central U.S.  including the intermountain West  and Canada. Their results, published in the journal Science in late April, provide the clearest picture to date of the cumulative ecological impact of the drilling frenzy of the last decade-plus.

The researchers wanted to broadly gauge the ecosystem services lost to oil and gas development  things like the land's ability to produce food and support wildlife. So they decided to quantify changes in "net primary production," essentially a measurement of a landscape's plant growth. By combining a large dataset on new wells drilled throughout the study region between 2000 and 2012 with annual satellite measurements of plant growth, they concluded that some 7.5 million acres had been stripped of vegetation  the equivalent of three Yellowstone National Parks. 

Much of the development took place on rangelands and croplands. The vegetation loss on rangeland represented enough forage to support 5 million cows for a month; the acreage of developed cropland was enough to grow 120.2 million bushels of wheat, or about 13 percent of the wheat exported in 2013. 

Julia Haggerty, an assistant professor of geography at Montana State University, and a co-author on the paper, says the findings "reinforce for me that we do very little assessment of oil and gas impacts beyond the scale at which most permitting decisions are made." 

Big as they seem, the numbers are actually pretty small when considered against the total landmass studied. But if current trends continue for another 10 or 15 years, the loss of vegetation could be much more consequential, significantly reducing the landscape's ability to store carbon, and possibly conflicting with food production, and other land uses. The losses thus far, the researchers note, may be long-term; reclamation typically isn't done until the end of the well's life, and even then, requirements and monitoring are spotty between states and on private land, where 90 percent of the drilling in the study took place. 

The point Allred and his colleagues want to make is that these are trade-offs we're making unconsciously. It would be wise, they say, to continue quantifying them and consciously decide how much land and ecosystem services we're willing to cede to oil and gas production. "This is kind of a thief in the night  it's just crept up on us," Allred explains. "Everyone's excited about drilling because it's great for jobs and energy independence. All of those things are important. We just wanted to say, 'This is what we're losing because of it.' We've decided up until now we're OK losing three Yellowstones. At what number are we not OK?"

Remember the Dust Bowl, he cautions. It stemmed from technological advances  combustion engines and tractors  that allowed people to farm almost anything. And they did. "That removed a bunch of natural vegetation and reduced the resilience of the region to drought," Allred says. An accumulation of small disturbances resulted in a big disaster. To be clear, he's not saying that drilling activity has put us at the precipice of a similar catastrophe, just that we need to pay more attention to what the small things add up to. "We have the technology to make sure (the Dust Bowl) doesn't happen again. We have the ability to monitor acre-by-acre. We can look at these cumulative effects."

Cally Carswell is a High Country News contributing editor based in Santa Fe, New Mexico.

Thumbnail image courtesy Flickr user Bryan Jones. 

High Country News Classifieds