Gases other than carbon dioxide accounted for nearly 15% of total U.S. greenhouse gas emissions in 2008, yet there has been minimal discussion of these other greenhouse gases in climate and energy legislative initiatives. Reducing emissions from non-carbon dioxide greenhouse gases, such as nitrous oxide (N2O), could deliver short-term climate change mitigation results as part of a comprehensive policy approach to combat climate change.
Nitrous oxide is 310 times more potent than carbon dioxide in its ability to affect the climate; and moreover, results of a recent scientific study indicate that nitrous oxide is currently the leading ozone-depleting substance being emitted. Thus, legislation to restrict nitrous oxide emissions could contribute to both climate change protection and ozone recovery.
The primary human source of nitrous oxide is agricultural soil management, which accounted for two-thirds of the N2O emissions reported in 2008 (approximately 216 million metric tons CO2 equivalent). One proposed strategy to lower N2O emissions is more efficient application of synthetic fertilizers. However, further analysis is needed to determine the economic feasibility of this approach as well as techniques to measure and monitor the adoption rate and impact of N2O emission reduction practices for agricultural soil management.
As the 112th Congress considers legislation that would limit greenhouse gas emissions, among the issues being discussed is how to address emissions of non-CO2 greenhouse gases. Whether such emissions should be subject to direct regulation, what role EPA should play using its existing Clean Air Act authority, and what role USDA should play in any N2O reduction scheme are among the issues being discussed. How these issues are resolved will have important implications for agriculture, which has taken a keen interest in climate change legislation.
Note: This summary was taken from the Congressional Research Service Report R40874 by Kelsi Bracmort.