Greenhouse Gases and Agriculture
By John Bennett
Saskatchewan Soil Conservation Association
There has been a lot of publicity around the issues of green house gas emissions (GHG) from burning fossil fuel and the potential hazards of global warming. Farmers need to understand how they will be affected as countries move to reduce GHG emissions. Of the six GHGs listed in the Kyoto agreement only three are relevant to agriculture: carbon dioxide (CO2), nitrous oxide (N2O) and methane (MH).
CO2 emissions come from burning fossil fuels and from oxidizing (burning) organic plant matter (carbon). Nitrous oxide is less well understood but it can come from nitrogen based fertilizers. Methane is an emission from ruminant livestock, like cattle. These are all "sources" of GHG.
Plants absorb CO2 emissions and change them to oxygen (O2) that is returned to the atmosphere and carbon (C) which is stored as organic matter. As farmers we manage thousands of acres of small biological scrubbers (plants) that extract CO2 form the atmosphere. This process of removing CO2 and storing it as organic carbon creates a "sink".
In simple terms the Kyoto agreement hopes to reduce the "sources" of GHGs and enhance removals of GHGs "sinks". Forests are considered as a "sink". Agricultural soils may also be included as a "sink".
As farmers we need to understand how we will be affected and how we should respond. First it is unlikely we will be able to eliminate fossil fuel consumption altogether however with one pass low draft seeding systems and by reducing or eliminating unnecessary tillage we can reduce fuel consumption. Secondly we can adapt practices that enhance the "sink" potential of our soils. As farmers we can "sink" more CO2 in our soils by using best management practices than we "source" by burning fossil fuels. We will likely see credits for CO2 removal. These credits may be worth money.
Here is a chart that came from the National Sinks Table Option paper. The forest sector table shows the potential size of "sink" and the costs associated. If you have ever picked roots you would not likely be willing to turn your field into a tree plantation. Perhaps the most important thing to note is the high cost needed in the short term to create a carbon sink with forests. Forest sinks have much greater potential in the long term.
This next chart shows the potential of agriculture soils to sequester CO2 in Canadian soils. It must be noted here that it is assumed that by 2008, forty percent of Canada’s agriculture lands will be farmed with the Best Management Practices (BMP) such as direct seeding, zero till and reduced summer fallow. The cost column is basically irrelevant as it represents some of the costs of agriculture extension programs in Alberta. The text of the paper recognizes the need for incentives to attract participation. It should be noted that N2O emissions would subtract from the potential of CO2 soil sinks.
To put forest and agriculture sinks in perspective we must understand that forest sinks are recognized in the Kyoto agreement. Agricultural soils are currently not recognized but likely will be included in the future. Forest sinks probably will not contribute much in the short term but have long term potential. If agricultural soils are included as sinks they can make a substantial contribution to Canada’s GHG emission challenge because they are already sequestering carbon at no cost. Unfortunately trees are easier to hug than soil. Hopefully the urban majority will recognize that deforestation is a symptom of unsustainable agriculture.
The following flow chart will help explain my views of how this issue will play out and its effects on us as farmers.
First let’s assume this issue is a hoax and global warming is a myth. Farmers would be smart to take the money from the speculative trades like the Iowa deal and spend it quickly. One would need to assume that the energy sector was foolish enough to cut a cheque in the first place and agriculture would profit at their expense.
Next let us accept that the scientists predicting climate change are correct. There are two possible outcomes. One, if there is little public concern there would likely be little government response and the value of sinks would be uncertain, but likely low. Secondly let’s take the view that global warming is a fact and that the public is aware of the potential problems global warming presents and demands action. The value of sinks would be considerably higher. In short public perception of the problem and the need to address the issue will determine the value of CO2 sinks.
There are several possible government responses. Let’s consider three.
On the carrot side, governments may address the risks we take as farmers by allocating resources for research that improves our ability to employ BMPs like direct seeding and zero till. This would make the adoption of these practices more attractive. As farmers we should be assertive that this research be directed by farmers not industry.
Industry directed research tends to develop solutions with higher costs borne by farmers. This adds to the considerable risk farmers already assume. I think policies which address risk reduction will ultimately prove the most successful. In the case of zero till we must make the public and policy makers aware of the complexities of management that result when tillage is removed. Policies like crop insurance and other safety net programs may actually act as disincentives to adapting BMPs.
On the stick side there could be a series of regulations. The government could dictate fertilizer types, rates, and application methods. There could be regulations restricting tillage and or fuel consumption. Punitive regulations would likely result in higher costs and reduced production and add to a farmer’s risk.
My best guess is that we will see a combination of all of the above and your sense of how it will come out will probably be as accurate as mine.
As farmers we must understand and be aware of the potential that the soils we manage have to remove and store (sequester) green house gases. We should think carefully before we approach the carbon credit trading arena to understand the value it can add to our farms as well as the liabilities that could come as part of the transactions.
Public awareness is needed to establish a clear link between soil and atmosphere steward ship. People must realize that deforestation at the global level is a symptom of unsustainable agriculture. The public should recognize that farming practices which contribute to healthy soils result in clean water and air.
Hopefully the non-farming population will understand the huge potential of soil sinks in atmospheric stewardship and the fact that only farmers can make it happen. Remember that uninformed consumers are dangerous legislators.
As farmers we will be affected by the outcome of political decisions whether or not we participate in the discussions. This issue is far too important to ignore.