Tuesday, March 09, 2010

Carbon Friendly Agriculture?

As climate crisis accelerates, our farmers are placed in the ever more precarious position of growing food for an increasing population in the face of increasingly bizarre weather patterns. Weather patterns are shifting   due to the increasing amount of energy trapped in our atmosphere by greenhouse gases.

And yet, farming offers the fastest way to slow climate crisis. This is because farmers manage photosynthesis. Photosynthesis is a biological process within green plants that pulls carbon dioxide out of the atmosphere and stores it in a stable, useful form: organic carbon. Organic carbon is the chemical basis of leaves, shoots, roots, fungi and all the other living things that make up healthy soils.


Good farmers can accelerate this process and pull huge amounts of carbon dioxide from the air into soil organic matter. You can read here about how increased soil organic carbon can help us manage dry and wet years better by storing water. And the practices that build soil organic carbon require more diverse cropping systems, making farmers (and us) less reliant in any one crop.

The most important thing we can understand is how we to stop climate crisis. On a heating planet, we must do anything to pull greenhouse gases out of the atmosphere. Bill Gates’ recent Ted talk   argued clearly that stopping greenhouse emissions must be our number one priority. Despite this powerful vision, he allows for agricultural emissions to continue as they are, despite knowing about one fourth of global climate emissions are from agriculture.

Can we continue to emit that much greenhouse gas? As it stands, we are seeing melting glaciers, an ice-free arctic, and are running the risk of going over many  tipping points   predicted by the scientific community. We’re currently at 390 parts per million of greenhouse gases in the atmosphere. The safe limit is 350 parts per million  . How can we get below 350 parts per million while continuing thirty percent of our emissions?

We can’t.

The good news is, we don’t have to. We can choose to embrace agricultural practice that does not emit greenhouse gases. We can choose agriculture that actually pulls carbon from the atmosphere.

Today thirty percent of  global greenhouse gas emissions from agriculture come mainly from producing synthetic fertilizer  , herbicides and pesticides. The industrial processes that produce these chemicals are incredibly carbon intensive. In fact, a recent study   found it is the MOST carbon intensive industry in the world.

What is worse is that application of synthetic chemicals to soil destroy  s its ability to store carbon.  
In organic, sustainable and regenerative farming systems, biological processes replace those chemicals. Rather than applying synthetic fertilizer, we can build fertility through nitrogen fixing plants. Rather than using pesticides we can rotate crops annually so that pests can’t find them. Rather than applying herbicides we can kill weeds using tillage or other means.

I’ll conclude with a specific idea. Imagine rows of corn growing in the Midwest, with barren soil in between them. A farmer adds synthetic fertilizer to the land for his corn. The soil only has one kind of root (corn) and cannot sequester very much carbon due to the synthetic fertilizer.

As fertilizer costs go up, our farmer tries a new approach. He plants clover between the rows of his corn. This has no effect   on the yield of his corn. The clover adds fertilization to his soil so he needs less (or no) fertilizer. And with twice as many kinds of roots in his soil, the increased diversity supports more life in the soil. The absence of synthetic fertilizer also helps the living things in his soil flourish.

Imagine the fields again. Every square inch is covered with green photosynthesizing plants. The soil is storing soil organic carbon faster and faster. And this farmer is helping to slow our climate crisis. That’s the best kind of carbon capture and sequestration I know of.



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