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Energy Sprawl
by -- March 22nd, 2016

We can bemoan the impact of the energy industry on natural lands in the U.S. The spoils of strip mining for coal cover thousands of acres of Pennsylvania. Coal mining, including mountain-top removal mining, has denuded 2200 square miles (5700 km2) of land, much of it in the Appalachian mountains in the past decade.  Between 2000 and 2012, the pads, tanks, roads, and pipelines that support the oil and gas industry were estimated to grow by 10,500 square miles (30000 km2), mostly in croplands and rangelands across America.

Suppose we examine the flip-side of energy sources, asking the question: how much land would be disturbed by an energy economy based solely on renewables? Already solar panels occupy a considerable area of land in the desert Southwest, and the growth of crops for bioenergy now accounts for 30 to 40% of the U.S. corn crop.

To hold the anticipated change in global temperature at < 2o C will require that 82 to 88% of the known coal reserves remain unburned from now to 2050.  Replacing coal with electricity from renewables is a major challenge, with major land-use implications.

Land-use intensity—the amount of land needed to produce a TerraWatt-hour (TWhr) of electricity each year—ranges from 1.9 to 2.8 km2 per TWhr per year for nuclear to 2.5 to 17 km2/TW-hr for coal and 433 to 654 km2/TW-hr/yr for energy crops that are burned in power plants. Thus, to replace the current electric power sources of the U.S. with bioenergy would impact an area at least 100X greater than that affected by coal and nuclear sources.[1]  Conversion of new areas to agriculture would release considerable quantities of carbon, now held in vegetation and soils, to the atmosphere, constituting a “carbon debt” that would take decades to recover by the use of carbon-neutral renewables.

Estimates of land-use intensity for wind (72 km2/TW-hr/yr) and solar (36.9 km2/TW-hr/yr) are also higher than for coal and nuclear energy.  Utility-scale solar projects are planned for 300 square miles (860 km2) of the Mojave Desert and the Central Valley of California.  No doubt, some of the land under solar panels and windmills can be used to support other uses, such as some crops and grazing.  But, the land’s value as natural habitat for biodiversity is compromised.  For solar, it may be best to avoid utility-scale projects and concentrate on distributed-generation, such as rooftop photovoltaic.

Providing energy using traditional sources is estimated to require more than 72000 square miles (206,000 km2) in 2030; providing a significant fraction with renewable could increase that by 1/3.

Renewables have many advantages, but lessening the impact of energy provision on natural habitat does not appear to be among them.

 

References

Alfred, B.W., W. Kolby Smith, D. Twidwell, J.H. Haggerty, S.W. Running, D.E. Naugle and S.D. Fuhlendorf. 2015. Ecosystem services lost to oil and gas in North America.  Science 348: 401-402.

Hernandez, R.R., S.B. Easter, M.L. Murphy-Mariscal, F.T. Maestre, M. Tavossoli, E.B. Allen, C.W. Barrows, J. Belnap., R. Ochoa-Hueso, S. Ravi, and M.F. Allen. 2014. Environmental impacts of utility-scale solar energy.  Renewable and Sustainable Energy Reviews 29: 766-779.

Lutz, B.D., E.S. Bernhardt, and W.H. Schlesinger. 2013. The environmental price tag on a ton ofmountaintop removal coal. PloS One http://dx.plos.org/10.1371/journal.pone.0073203.

McDonald, R.I., J. Fargione, J. Eiesecker, W.M. Miller, and J. Powell. 2009.   Energy sprawl or energy efficiency: climate policy impacts on natural habitat for the United States of America.  Plos One 4: e6802.

McGlade, C. and P. Elkins. 2015. The geographical distribution of fossil fuels unused when limiting global warming to 2oC.  Nature 517: 187-190.

Searchinger, T., R. Heimlich, R.A. Houghton, F. Dong and A. Eloheid. et al. 2008. Use of U.S. croplands for biofuels increases greenhouse gases through emissions from land-use change.  Science 319: 1238-1240.

 

 

[1] This does not include the area impacted by air pollution from coal-fired powerplants

3 Comments

  1. Phil Carlson
    Mar 22, 2016

    France gives us a great example of what the countryside looks like where the energy mix is 75% nuclear and 25% hydropower. Lots of beautiful agricultural land with pristine air and no carbon generation except by vehicles and manufacturing, which will eventually be electric as well! The French accomplished this in a few decades after the oil crisis in the 70’s. We can do it too with safer and more efficient generation 4 nuclear technology.

    • Bill Schlesinger
      Bill Schlesinger
      Mar 22, 2016

      Nuclear doesn’t use much land, but see my grave misgivings about the proliferation of nuclear power, in the blog post of 11 January 2016

  2. Manna Jo Greene
    Mar 22, 2016

    Bill, There is huge potential for off-shore wind, which will not use terra firma per se, but is enough to power NYC — in fact, the entire East Coast of the US, according to Mark Z. Jacobson of Stanford University. As for solar, there are many opportunities for community- and utility-scale projects, which are appropriate and leave natural areas intact and undisturbed for the many valuable ecosystem services they provide. For example, large-scale solar can adaptively reuse closed landfills, brownfield sites and less productive areas of farmlands. Distributed solar is a good start, but we need to do both, carefully and appropriately, while protecting our farmers and other large landowners from predatory leases, which are now being offered by some unscrupulous solar developers. That said, it is really time to transition away from our long-standing dependence on fossil fuel and our 50+ year dependence on nuclear power, which no longer serve us well and are harmful to the biosphere, to a truly Green Energy Economy based on renewables with storage and energy efficiency.

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