Rising Acres

Soil Carbon Restoration: Can Biology Do the Job?

A great deal of discussion in scientific and governmental circles has been focused recently on how to deal with greenhouse gas emissions and the resulting weather extremes they have created. Most analysts believe we must stop burning fossil fuels to prevent further increases in atmospheric carbon, and find ways to remove carbon already in the air if we want to lessen further weather crises and the associated human tragedies, economic disruption and social conflict that they bring.

August 14, 2015 | Source: Northeast Organic Farming Association/Massachusetts Chapter, Inc. | by Jack Kittredge

Introduction

A great deal of discussion in scientific and governmental circles has been focused recently on how to deal with greenhouse gas emissions and the resulting weather extremes they have created. Most analysts believe we must stop burning fossil fuels to prevent further increases in atmospheric carbon, and find ways to remove carbon already in the air if we want to lessen further weather crises and the associated human tragedies, economic disruption and social conflict that they bring.

But where can we put that carbon once it is removed from the air? There is only one practical approach — to put it back where it belongs, in the soil. Fortunately,  this is not an expensive process. But it does take large numbers of people agreeing to take part. Since few people will change what they are doing without a good reason, we have written this short paper. We hope it explains the problem of carbon dioxide buildup and climate change, how carbon can be taken out of the atmosphere and restored to the soil, and the advantages that can come to farmers and consumers from growing in carbon-rich soils.

Climate Change

Weather anomalies are notoriously difficult to document. To do so requires good data over a long time, and clear standards for what constitutes an anomaly. Recently, however, as more and more people are interested in the topic, development of the data and standards has progressed.  The key factors in extreme weather are excessive heat, precipitation, and air moisture. Recent studies have found that monthly mean temperature records, extreme precipitation events, and average air moisture content have all risen over the last 50 to 150 years. (Coumou) Most scientists believe that the cause of such unpredictable extremes is the “anthropogenic” (originating in human activities) buildup of greenhouse gases(GHG) in the atmosphere. Rigorous modeling studies and analyses of extreme weather events have found human-caused climate change to be a contributing factor in many such extremes. (Peterson) According to the American Association for the Advancement of Science, “Based on well-established evidence, about 97% of climate scientists have concluded that human-caused climate change is happening.” (AAAS)

How Greenhouse Gases Cause Climate Change

Greenhouse gases, primarily carbon dioxide but also methane, ozone and nitrous oxide, have for millions of years been emitted from soil and water into the atmosphere by natural processes like animal respiration, swamp out-gassing and releases from nitrogen fixing bacteria. (EPA) Those gases are also broken down by natural processes and returned to their sources in a continual cycle. As long as the amount of greenhouse gases emitted and the amount returned to sources remain balanced, they will not cause climate change. We need a certain level of greenhouse gases in the atmosphere. They trap solar radiation so that the earth reflects less of it back into space. This raises the amount of heat driving the planetary forces that cause weather. If we did not have some such gases, earth would be frozen year-round and far too cold for human life. The level of a gas in the atmosphere is measured in units called “parts per million” (ppm). Nitrogen, Oxygen and Argon, the primary gases in our atmosphere, collectively account for 999,000 ppm. Throughout human history the atmospheric level of carbon dioxide has stayed at roughly 280 ppm, or less than 0.03%.