Turning air into dirt: Using atmospheric carbon and solar energy to grow the water-holding soils that can feed the world

Our best opportunity for an effective, near-term, and broadly inclusive strategy to address climate change lies beneath our feet. The soil contains more carbon than the atmosphere and forests combined. Though human actions and decisions control them, these enormous flows of carbon in and out of the soil are invisible, and largely outside our awareness and intention.

We can take advantage of this opportunity if we can see it. What follows is not a pet theory or idle speculation. It is based on years of on-site reporting on farms and ranches on several continents.

Technology alone, or guilt over technology, won't fix climate change. Fossil-fuel burning contributes only about 3.4% of the annual global flow of carbon dioxide into the atmosphere. Deforestation or land use change, about 0.75%.[1]

Though just a sliver relative to the big picture, these emissions contribute to the likelihood of dangerous climate change. They're bad. But what might happen if we reduce them, or stop them?

In 2007 the Intergovernmental Panel on Climate Change noted that "both past and future anthropogenic carbon dioxide emissions will continue to contribute to warming and sea level rise for more than a millennium, due to the time scales required for removal of this gas from the atmosphere."[2] Furthermore, "complete elimination of CO2 emissions is estimated to lead to a slow decrease in atmospheric CO2 of about 40 ppm over the 21st century."[3] In other words, with the stiffest reductions imaginable, it may take generations to get atmospheric concentrations down to what climate scientist James Hansen calls safe levels—350 parts per million.

Burning fossil fuels and forests also generates aerosols or fine particles that reflect solar radiation back into space, with significant cooling effects.[4] Loss of these short-lived aerosols would likely result in immediate warming.

FAO recognizes carbon farming

At the recent soil carbon conferences (West Lafayette, Indiana, and Orange, New South Wales), the United Nations Food and Agriculture Organization recognized conservation agriculture as a way to sequester carbon in the soil, and recommended that soil carbon be included in the Kyoto treaty as a tradable offset.

Here are two pdf files from the conferences (right click and save link as to download).

UNCCD executive secretary highlights link between land degradation and climate change

“The land can be… an opportunity to solve most of the ongoing global crises,” Luc Gnacadja, Executive Secretary of the UN Convention to Combat Desertification (UNCCD), told a news conference in New York.

“If we want to tackle climate change challenges, we must look to the untapped potential of the soil to sequester carbon,” said Mr. Gnacadja, calling it a “win-win” situation. “By doing that, we are improving biodiversity of the soil ecosystem and improving the productivity of the soil, therefore impacting the livelihoods of affected populations.”

The Wrong Trousers

Last year Steve Rayner and Gwyn Prins wrote a fine paper on climate change policy. Though the authors do not show awareness of the soil carbon opportunity, or of biological factors in the carbon cycle in general, the 41-page paper is a splendid takedown of the top-down carbon market approaches exemplified by the Kyoto protocol, and projects a framework into which the soil carbon opportunity fits nicely.

Rodale Institute on the soil carbon opportunity

The Rodale Institute has recently come out with a policy document titled "Regenerative Organic Farming: A Solution to Global Warming."

"Successful implementation of regenerative organic farming practices on a national basis will depend on two factors: a strong bottom-up demand for change, and a top-down shift in state and national policy to support farmers in this transition."

Download the report from http://www.rodaleinstitute.org/20080425/gw6

Tool testing

For the really big problem(s) that we face such as biodiversity loss, scarcity of food and water, land degradation, and climate change, the available tools might be crudely lumped into these four columns. The three rows are a crude simplification of Holistic Management testing guidelines. The last row is similar to the social weak link guideline. For example, if we want to provide incentives or payments for ecosystem services, it must first become conventional wisdom for the organization to disburse the money.

Offsets or ecosystem services?

In the United States, the current carbon market at the Chicago Climate Exchange buys offsets or "pollution credits" as some have called them. The amount of carbon sequestration purchased is directly related to emissions of carbon into the atmosphere by industries, for example. As the trading price of carbon offsets increases, presumably emissions will go down, but then so will the purchase of offsets.

The politics of soil carbon

Building soil organic matter on a large scale could reverse global warming, but it also has near-term, local benefits. These include better water cycling (fewer floods and droughts, more moderate and consistent streamflow, as well as better water quality), better mineral cycling (e.g. less nitrate pollution), increasing biodiversity above and below ground, an increase in the quantity as well as quality of human food, less reliance on chemical and fossil fuel inputs to agriculture, and greater self-sufficiency and economic independence of the agricultural sector.


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