We have heard so much in the news media about global warming lately, and it seems that everybody has an idea of how to fix it. This is what I understand about the changing climate. The gases in the atmosphere act like a blanket around the earth, trapping heat from the sun, much like a greenhouse. While I am not sure if this is part of a normal cycle, or if something we have done is causing it, many people believe the increasing amount of carbon dioxide (CO 2 ) emitted from human activities plays a role. Other gases, like methane and nitrous oxide are even more of a problem. Methane is said to have 21 times greater impact than CO 2 , and nitrous oxide is 300 times worse than CO 2 . Armed with this knowledge, it appears that reducing emission of these “greenhouse” gases could reduce the problem.
Scientists believe that trapping or sequestering CO 2 in crops or in the soil may be part of the answer. Land management practices such as no-till, strip-till, grassland, and forestry are known to contain these greenhouse gases, a concept known as “carbon sequestration”. Here is where it gets interesting. There are people and businesses that are willing to pay farmers who sequester carbon, referred to as “carbon credits” (one carbon credit is equal to one metric ton of CO 2 ).
Carbon credits are traded on the Chicago Climate Exchange (CCX) in the same way grains are traded on the Chicago Board of Trade. Factories and electric generating companies who are trying to reduce their greenhouse gas emissions, but are not able to do it fast enough or as cost effectively, are willing to purchase carbon credits like those from conservation farming practices. Farmers may not be able to sequester enough carbon individually to make them a player in this game, so an “aggregator” acts on the behalf of many producers. The aggregator purchases the carbon credits from of these smaller operations and sells them on the CCX to parties who want them.
Currently carbon credits are trading for about $3.90, and this translates into about $3.00 per acre, according to Mark Wilson of Land Stewards. Carbon credits, when added to the other income sources available on an acre, could be the icing on the cake. Europe has a similar program and carbon credits are much more valuable than we have seen here. This could be a possible sign of things to come in the U.S.
There are other ways to get into the carbon credit business. Livestock farms with certain types of manure handling systems can cover a portion of their manure storage and collect the methane that is produced by anaerobic digestion of the manure. Carbon credits can be earned by preventing the release of greenhouse gases, such as methane. Jim Jensen, who is with Environmental Credit Corporation (ECC), said his company is in the business of buying and selling carbon credits. His company is willing to pay to install a lagoon cover to prevent the release of the greenhouse gasses (the term lagoon is used here for both true manure processing lagoons and earthen manure storage basins). This is a passive type of methane digester. ECC is willing to pay the cooperating livestock producer 15% of the annual carbon credit value, and when the investment is paid for, payments can increase to 25%. The methane collected can either be flared off or used by the farm at 25% of the market value of the gas.
If I have aroused your curiosity, you need to know that only certain types of farms are offered this deal. Each operation has to be an economically feasible endeavor for ECC. At this time it looks like a farm with at least 1,500 cows or 6,000 hogs will meet this need. The gas is likely to contain some hydrogen sulfide, which is corrosive, so it can only be burned in certain types of appliances, or may be “cleaned” for use in more conventional equipment.
One other issue may help you decide if this is something for your farm. The covers work best on lagoons which have a static level, and deeper is better. First the sand or other solids need to be removed from the manure stream. The liquid material then must move through the covered pond or tank, being retained for about 60 days. Farms that have a two or more manure storage basins in series are more likely to fit the bill. The carbon credits are earned based on the amount of methane prevented from entering the atmosphere.
Jon Rausch, OSU’s Environmental Management Program director, pointed out several other benefits of lagoon covers. The synthetic impermeable covers can exclude precipitation, increasing storage capacity and reducing the manure hauling costs. The cover can also reduce offensive odors, and improve the fertilizer value of the manure, as less ammonia nitrogen will be lost to the environment during storage.
We really are entering a new age of agriculture. For more information about carbon credits and carbon sequestration contact your Extension office or Jim Jensen at the Environmental Credit Corporation (206-297-0698).