1. Emissions From Fertilizer Production
Nitrogen-based fertilizers accounted for 59% of total U.S. fertilizer consumption in 2010,4 but were responsible for approximately 90% of emissions from fertilizer production.5 A 2012 study found that fertilizer manufacturing contributed 282-575 million metric tons of carbon dioxide equivalent (MMT CO2 eq.) globally, as compared to 5,120–6,116 MMT CO2 eq.
of direct emissions from agriculture.6 That study further notes that nitrous oxide emissions from fertilizer application are about 40% of total agricultural emissions, suggesting that emissions from fertilizer manufacturing are equivalent to about 12-30% of the emissions from fertilizer application. Emissions data indicate that the average emission rate for fertilizer manufacturing scaled to production capacity in the United States is about 2.57 metric tons CO2 eq. per metric ton of nitrogen (as ammonia) produced,7 but the global range is very large, from 0.45 to 9.5 metric tons CO2 eq. per221
ton nitrogen produced, depending on the type of nitrogen fertilizer being manufactured.8 These emissions are additional to emissions resulting from the application of fertilizer on croplands, meaning that the climate benefits of reducing fertilizer use, if accompanied by a commensurate reduction in fertilizer production, are significantly greater than indicated by direct emissions alone and that significant climate benefits may be achieved by tailoring the types of fertilizer manufactured.
New ammonia production facilities are approximately 30% more energy efficient than older ones, further indicating that this sector’s emissions could be significantly reduced by modernizing production processes.9 However, due to thermodynamic constraints to efficiency, emissions cannot drop much further through efficiency measures alone.10
In addition to greenhouse gas emissions with direct climate impacts, fertilizer manufacture and application also contribute to air and water pollution through emissions of ammonia. As discussed above in Chapter VI.A, the U.S.
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Environmental Protection Agency (EPA) has the authority to impose emission limits on ammonia, which can—depending on the control technologies used—also reduce greenhouse gas emissions.11 In 2017, nitrogen fertilizer plants in the United States accounted for 23% of total ammonia emissions attributed to large stationary sources.12 Despite the fact that ammonia is a precursor to particulate matter pollution, which results in human health hazards and haze causing thousand of deaths annually in the United States,13 EPA has not yet promulgated emission limitations on nitrogen fertilizer manufacturing.14 Indeed, because ammonia is also often deposited onto aquatic ecosystems, where it leads to both water and air pollution,15 including nitrous oxide emissions, EPA could also potentially limit these emissions under the Clean Water Act. Any of these actions would likely reduce the direct and indirect greenhouse gas emissions from fertilizer manufacturing.
In addition to the many opportunities to use fertilizer more efficiently outlined in Chapter IV above, there is also some promise in facilities that can produce nitrogen fertilizer from biomass instead of natural gas,16 although any use of biomass as feedstock must address the land use impacts or carbon opportunity cost discussed in Chapter III above. Alternatively, proposed facilities could produce both electricity and fertilizer accompanied by carbon capture and storage (or reuse),17 which could produce fertilizer with very low greenhouse gas emissions. The government should support research on such projects.
More on the topic 1. Emissions From Fertilizer Production:
- A variety of federal, state, and local agencies outside of the U.S. Department of Agriculture (USDA) support or regulate agricultural production.
- This chapter begins by describing how the climate crisis threatens to disrupt agricultural production at immense cost to society.
- The Birth of a Hybrid: Production of Scientific Knowledge on Glucosamine
- Postproduction greenhouse gas emissions, while significant, have not been comprehensively catalogued in the United States.20
- 2. U.S. Agricultural Greenhouse Gas Emissions
- 1. Global Agricultural Greenhouse Gas Emissions
- 3. State-Level Agricultural Greenhouse Gas Emissions
- 2. Landfill Waste Emissions
- In August of 2018, Missouri became the first state in the United States to regulate the labeling of artificial meat, with a statute defining meat as something “derived from harvested production livestock or poultry.”1
- 1. Processing, Packaging, Distribution, and Marketing Emissions
- A. Upstream: Greenhouse Gas Emissions From Farm Inputs
- There are a number of ways that the private and nonprofit sectors can boost carbon farming and help reduce net agricultural emissions.
- B. Downstream: Emissions From Food Processing, Packaging, Marketing, and Waste