The Climate Action Reserve (CAR) has developed a Nitrogen Management Project Protocol (NMPP) for the agricultural sector to provide guidance on how to quantify, monitor and verify greenhouse gas (GHG) emission reductions from improving nitrogen use efficiency in crop production. The protocol was adopted by CAR in June 2012. It is available online.
Within the same field, scientists at the National Science Foundation’s (NSF) Kellogg Biological Station (KBS) Long-Term Ecological Research (LTER) are putting the finishing touches on a program called the nitrous oxide greenhouse gas reduction methodology. This program, which is being conducted in partnership with the Electric Power Research Institute, would pay farmers to apply less nitrogen fertilizer in a way that doesn’t jeopardize yields. When farmers reduce their nitrogen fertilizer use, they can use the methodology as a means of generating carbon credits. These credits can then be traded in carbon markets for financial payments. The methodology was recently approved by the American Carbon Registry and is in its final stages of validation by the Verified Carbon Standard.
In the United States, agriculture accounts for almost 70 percent of all nitrous oxide emissions linked with human activity. Nitrous oxide is one of the major gases contributing to human-induced climate change and has a lifetime in the atmosphere of more than 100 years. In addition, a molecule of nitrous oxide has more than 300 times the heat-trapping effect in the atmosphere as a molecule of carbon dioxide.
To achieve desired production levels of crops such as corn, most farmers apply synthetic nitrogen fertilizer to their fields every year. While the production of nitrous oxide through microbial activity is a natural process in soils, the large-scale application of fertilizer has greatly increased the amount of nitrous oxide in soils. Once nitrogen fertilizer hits the ground, it is hard to contain and is easily lost to groundwater, rivers, oceans and the atmosphere. Nitrogen lost to the environment from agricultural fields is nitrogen not used by crops, which costs farmers money and degrades water and air quality. Farmers already manage fertilizer to avoid large losses, but to reduce losses further it currently costs more money than the fertilizer saves.
Carbon credits provide an incentive for farmers to apply fertilizer more precisely, rather than to reduce yields. In addition to providing an economic incentive, the methodology is a tool that farmers can apply to enhance their land stewardship.