“A nation that destroys its soil destroys itself”
Franklin D. Roosevelt
The challenge that president Obama faces entering office has been compared with that of Roosevelt during the great depression. With all of the high hopes surrounding Obama’s environment and energy policies, there is one issue that Roosevelt seemed to understand that Barak Obama must learn in order to have coherent policies on global warming and the environment: the depletion and degradation of North America’s topsoil.
The Obama administration and Canada’s government need to make topsoil a cornerstone of the emerging policies to address global warming, food security, and rural economies.
In his recent congressional address, Barak Obama was adamant that America must not leave its massive budget deficits to future generations. There is no mention, however, of this looming deficit in natural capital that could threaten the ability of future generations to even feed themselves, let alone enjoy prosperity.
Every year in North America we lose topsoil at an average rate that ranges anywhere from 10 to hundreds of times the rate at which new soil is formed. Within a century, the regions in North America blessed with some of the world’s best agricultural land have lost up to 8 inches of topsoil (average topsoil depth is 12-16 inches). In addition to future concerns, there are immediate consequences. Studies have found that losing an inch of topsoil reduces corn and wheat yields by an average of 6 percent (Eco Economy, Lester Brown).
Conserving and rebuilding soil must become central in efforts to combat climate change. When the carbon in soil is exposed to oxygen through tilling it forms the greenhouse gas carbon dioxide. Strategies central to Organic farming such as no-till, improved grazing, nutrient management, and cover cropping can prevent the release of carbon and sequester the existing carbon from the atmosphere. A 2004 Ohio State University study published in Science found that carbon sequestration in soils has the potential to offset fossil fuel emissions by 0.4 to 1.2 gigatons of carbon per year, or 5-15% of global fossil fuel emissions. While there is still debate about sequestration rates, the study’s author Ratten Lal states that American soils have the potential to soak up 100 million tons of carbon per year, about the equivalent to half of all the nation’s auto emissions.
The topic of soil erosion is not new and sequestration is starting to be understood. President Obama even included carbon sequestration in his “Plan for Rural America”. The issue is not that topsoil loss and carbon sequestration is being ignored, but that it is not being given enough attention in world focused on climate change. Perhaps this is because topsoil does not have the symbolic appeal of something like wind turbines and is not as direct to people’s lives as energy. Transforming to a renewable energy economy, however, will be a long-term endeavor and fossil fuels will likely be a primary energy source for decades to come. Soil carbon sequestration could be an effective way to reduce atmospheric carbon dioxide for the next decades until fossil fuels can be replaced.
There is the need for the coherent integration of climate change and agriculture policies. Obama’s continued support for biofuels drives a stake into the heart of any policies to address soil health, the environment and energy. Even if all U.S. corn were converted to biofuel it would provide less than 20% of the nation’s liquid fuel use. Biofuels will intensify the current production of row crops (which cause relatively high erosion rates). Any rhetoric about how biofuels cut greenhouse gas emissions does not take into account carbon emissions resulting from land use changes inherent in growing crops for fuel. A recent study in Science found that using corn based biofuel doubles greenhouse gas emissions over 30 years, while switchgrass based fuels increased emissions by 50%. While there is a role for using waste products for small-scale biofuel production, soil and climate change is yet another reason why large-scale biofuel production (as supported by Obama) is a bad idea. If the intent of these policies is to support rural economies there are surely much better ways to do it.
While farmers and policy makers have taken steps to address soil erosion, there is a tremendous need to put a greater value on soil conservation. The inclusion of soil in carbon trading has begun, but the current value of credits does not seem to be enough to address the importance of this topic. One possibility is to boost market demand for food grown with farming practices (such as Organic) that build and conserve soil. Another would be to make soil conservation (and other environmental services) a precondition for receiving agricultural subsidies.
With so much emphasis on the need to build a ‘knowledge economy’ and ‘green jobs’, agriculture could be recognized as a vibrant, ideas driven industry where consumer education and job training show the connection between food production, global warming, health, the environment.
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