Drilling for oil and gas has caused long-lasting damage to ecosystems across Canada and the US, according to a study published today. The findings lend new weight to longstanding concerns over the resurgence in domestic fossil fuel production, as well as the complex land use regulations that make environmental monitoring more challenging.

The paper, published in the journal Science, examines the impact of oil and gas production on terrestrial plant growth, using a metric called net primary production (NPP). NPP can be used to gauge the health of the ecosystem. Using satellite data from 2000 to 2012, the authors found that oil and gas production reduced NPP by about 4.5 Tg of carbon or about 10 Tg of biomass through the loss of vegetation — the mass equivalent of 30 Empire State Buildings. Croplands lost the equivalent of 120.2 million bushels of wheat over that period — about 13 percent of all US wheat exports in 2013 — while rangelands lost vegetation totalling more than half the public grazing lands managed by the Bureau of Land Management.

American oil and gas production have soared in recent years, and the boom isn't expected to subside anytime soon. Today's study finds that between 2000 and 2012, well pads, roads, and storage facilities built for oil and gas development occupied about 3 million hectares of land — the equivalent of three Yellowstone National Parks. As demand for biofuels and agriculture increases, the authors write, oil and gas activities may spread even further into unused rangelands. The ecological damage they've already wreaked could be permanent.

"These are semi-arid landscapes, this is not lush countryside," says co-author Steve Running, a professor of forest ecology at the University of Montana. "So that land can sit there for centuries before it grows much of anything if there's not some reclamation and revegetation done."

Landscape impacts of oil and gas development. (Chris Boyer / kestrelaerial.com)

Previous studies have analyzed the environmental impacts of oil and gas drilling in the US, but most have focused on specific regions or aspects of biodiversity, such as habitat loss or water resources. The study released today takes a broader, more comprehensive approach, covering more than 2 million oil and gas wells across the US and Canada. And although others have used NPP to measure the health of ecosystems affected by fossil fuel development, experts say this study is the first to do so on such a large scale.

"NPP is as important in agricultural productivity as it is in supporting wildlife," says Julia Haggerty, an assistant professor of geography at Montana State University and one of the study's co-authors. Measuring biodiversity changes in terms of NPP also makes it easier to understand the trade-offs involved in oil and gas development. "So if you're beginning to compromise that, you can begin to think in systematic ways about the trade-offs that are possible... it forces us to think on a broader scale than we typically do."

The Obama administration has touted this surge in oil and gas as a driver of economic growth and an important step toward reducing US dependence on foreign oil. But there are major concerns over the fossil fuel industry's environmental impact, especially with regard to hydraulic fracturing, or fracking. This year, the White House introduced tighter regulations for fracking companies, amid widespread uncertainty about long-term effects on public health.

"What they've done here is unique," says Timothy Johnson, an associate professor of energy and the environment at Duke University, who was not involved in the study. "I haven't seen this sort of analysis in the literature." But he says it may be difficult to sway public opinion with statistics on vegetation declines, however dramatic they may be. "It would help to have more of the ‘so what?'" Johnson says. "They still need to make that connection to grab the public."

For now, though, the authors say policymakers are their primary target. "We see this paper as a wake-up call to our land managers and policymakers that we need to seriously regulate these industries to revegetate these areas once production is done," Running says. "The industry won't do it on their own just for fun."