Repeating the history of economic expansion in the Great Plains

"We speak of farmers and plows on the plains and the damage they did [to the Great Plains], but the language is inadequate. What brought them to the region was a social system, a set of values, an economic order."

- Donald Worster

The scene is the United States, the early 1900s. A population blooming like algae across the Eastern seaboard seeks more space to unleash its expansionist fever, galvanized by the gasoline engine and maturing industrial revolution. Farmers descend onto the Great Plains, plowing their way through pristine grasslands with newly mechanized farming equipment^1,2. Agricultural production booms, supporting ever larger populations settling into the rich frontier. Life seems good.

But subtle changes to the Great Plains go unnoticed. Plows used with unsustainable farming practices wipe out the grass roots that held together the loose soil typical to the region. Rainfall is initially adequate but begins to decline. In 1934, the first of three droughts hits; the other two span the next six years. Lack of rain and strong winds kick up the uprooted soil, billowing dust storms throughout Kansas, Colorado, and New Mexico, and destroying any chance of harvest. Families abandon farms no longer viable for food production as 3.5 million people evacuate Great Plains to find work and sustenance elsewhere.²

This scene was one of human tragedy and economic catastrophe. By the end of the droughts in 1939, more than 75% of the topsoil had blown away in the storms, and erosion had eaten away at previously healthy soils amid the grasslands. Only after such extreme disruption did the United States government act. President Roosevelt initiated policies to educate farmers about sustainable anti-erosion practices and to regrow plants that held the peripatetic soil in place.

Have we learned from such a disaster? Have we gathered more data about the effects of overzealous economic expansion and responded more quickly when necessary? The answer may not be encouraging. Today, it is not farming but fuel that entices us to the Great Plains. A new policy paper³ in Science provides the first set of quantitative data about how oil and gas well expansion in central North America has disrupted ecosystems and destroyed huge amounts of available biomass. Once again, we appear to be acting first and understanding the ecological consequences later.

Since 2000, we have constructed about 50,000 new oil and gas wells (mainly hydraulic fracturing wells) throughout central United State and Canada to respond to increasing energy demands. These projects replace huge areas of potential cropland or rangeland (regions where animals graze and hunt) with well pads and roads for transportation. This is just part of a trend that began around 1900 when oil became a dominant source of energy.

So how do we quantitatively measure the impact of such rapid expansion? Researchers must find a way to measure how biomass changes over time as more wells appear. To do this, they use satellite data to measure net primary production (NPP), which is the amount of carbon fixed by plants to turn into biomass (excluding that used for plant respiration). Satellites measure how much light is reflected by plants in various regions to determine how much light energy is absorbed. This value is then weighted by the efficiency of different plants' ability to convert light to useful energy. The resulting value is NPP, a measure of available biomass that serves as the bedrock for all ecosystem services in the area (see details of the model here).

For the first time, researchers have used this methodology to measure the change in biomass in the central United States and Canada each year since 2000. In addition, they have accounted for the increase in gas pads and connecting roads with the same resolution (~250 square meters) to better associate vegetation loss specifically with well development.

As you can probably guess, vegetation has decreased due to the economic expansion, but the numbers are quite dramatic. The study estimates that we lost about 120 million bushels of wheat in cropland between 2000-2012, or 6% of all wheat produced in 2013 and 13% of exports. Regarding rangeland, the biomass lost would have supported roughly 250,000 animals for a year.

The study does point out that the well pad and road expansion only take up about 11,000 square miles, a seemingly minuscule amount compared to the 9.3 million square miles of land on North America. But ecosystems rely on specific migratory pathways, hunting and foraging grounds, and breeding areas that can be disrupted by sporadic well placements that are not informed by the locations of vulnerable regions. Raw square mileage is especially meaningless when discussing the impact of road systems, as they can cut through large swaths of territory that prevent migration or disrupt feeding grounds.

So what can we do about this? The first step should be to make sure policymakers know about this data. However, even then change will be difficult. About 90 percent of new wells occur on private land, which is often difficult to regulate.

Most new policies must come from local municipalities and states, but regions that need to be protected often cover tracts of land that do not follow our human-made borders. Therefore, cooperation between communities will be imperative to coordinate cooperative efforts to protect ecosystems deemed important by scientists studying a particular area. The Dust Bowl farmers did not have the data available to make informed decisions. We have that power now - we just need to recognize it and use it.

The potential effects of unregulated oil and gas well expansion today may be different from the results of mechanized farming in the Dust Bowl era. In the 1930s, the consequences were food scarcity, home displacement, and further harm to the Depression-era economy. Today, we are more concerned about species diversity, habitat conservation, and available cropland. But in each case, we allow technology to run rampant before we understand its effects. And that is not the fault of the technology, but of the culture in which it is used. The passive language of technology pulling us along a particular pathway into the future is seductive - the inertia of machines is strong. But we should never forget that behind each technology is a human decision to pursue a certain vision of progress. That decision begins and ends with us.

References

1. "The American Experience: The Drought." http://www.pbs.org. Retrieved May 8, 2015.

2. Worster, D. "Dust Bowl: The Southern Plains in the 1930s." Oxford University Press, 2004.

3. Allred BW et al. "Ecosystem services lost to oil and gas in North American". Science, 348, 401 (2015).

Photo Credit

Great Plains photo courtesy of Blamfoto on Wikipedia