Grantee Research Project Results

2017 Progress Report: Integrated Analysis of Land Use-Based Policies for Improving Air and Water Quality: A Focus on Agricultural Reactive Nitrogen and Wildland Fire Emissions as Climate, Land Use and Anthropogenic Emissions Change

EPA Grant Number: R835880
Title: Integrated Analysis of Land Use-Based Policies for Improving Air and Water Quality: A Focus on Agricultural Reactive Nitrogen and Wildland Fire Emissions as Climate, Land Use and Anthropogenic Emissions Change
Investigators: Russell, Armistead G. , Burtraw, Dallas , Driscoll, Charles T. , Odman, Mehmet Talat , Shih, Jhih-Shyang , Siikamäki, Juha , Smith, Richard
Current Investigators: Russell, Armistead G. , Burtraw, Dallas , Driscoll, Charles T. , Odman, Mehmet Talat , Shih, Jhih-Shyang , Smith, Richard
Institution: Georgia Institute of Technology , Syracuse University , United States Geological Survey , Resources for the Future
Current Institution: Georgia Institute of Technology , Resources for the Future , Syracuse University , United States Geological Survey
EPA Project Officer: Chung, Serena
Project Period: January 1, 2016 through December 31, 2018 (Extended to December 31, 2020)
Project Period Covered by this Report: January 1, 2017 through December 31,2017
Project Amount: $789,820
RFA: Particulate Matter and Related Pollutants in a Changing World (2014) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air

Objective:

Agriculture-related reactive nitrogen (N_R) and wildland fire emissions are playing an increasingly more prominent role in the formation of atmospheric particulate matter (PM). Those sources can also impact water quality and ecosystem structure and function through the deposition of reactive nitrogen to sensitive environments. While nitrogen and sulfur oxides and organic emissions are being markedly curtailed by traditional control strategies, alternative approaches are needed to address reduced nitrogen (e.g., ammonia) and fire emissions. Land use-based policies can be an attractive approach to improve air quality with the co-benefit of decreasing reactive nitrogen deposition and improving water quality. An integrated modeling framework is being developed to investigate a range of land use based policies to mitigate particulate matter levels, atmospheric deposition and associated impacts on water quality and sensitive ecosystems. Land use policies are being assessed across multiple environmental endpoints of concern, with a focus on identifying cost effective strategies and those with benefits in one or more media.

Progress Summary:

During this reporting period, work has focused on collection and analysis of divergent future land cover (LC) projections, evaluation of the impacts of climate change on LC-related sources, assessment of N loss due to cropland NH₃ emissions and N yield gain from mitigation measures, and evaluation of the cropland NH₃ emission change on air quality:

Collection and analysis of divergent future land cover projections: Due to the project need, we collected future land cover (LC) projections currently available and analyzed their future trends in different land cover types. A total of 16 LC projections from four LC products were collected, including Land-Use Harmonization (LUH) v2 (RCP26, RCP 34, RCP45, RCP60, RCP70, and RCP85), Global Change Assessment Model (GCAM) Land Cover Projection (ref, 2p6, and 4p5), downscaled LUH Projection provided by Tsinghua University (rcp26, rcp45, rcp60, and rcp85), and LandCarbon Projection from US Geological Survey (a1b, a2, b1). We found that, between different products (such as LUH v2 RCP45 and GCAM rcp45), the projected LC changes are different because the projections have used different Shared Socioeconomic Pathways (SSPs) as well as being based on different integrated assessment models and/or projection methods (such as the story-and-simulation approach and the econometric approach). Therefore, even if LUH v2 RCP45 and GACM rcp45 both have a 4.5 W/m² forcing constraint, they may be assuming very different pathways, and thus the future trends in LC could be very different. For example, although most projections show an increasing trend in future urban land, the change percentages range from 0% to 38%. For other LC types, both the magnitudes and the signs of changes could be different. This indicates the large range of probability of future LC change. Without a representative of future LC change, we thus determined that assessment of this project should be conducted based on multiple LC projections whenever possible.

Modeling the impacts of LC and climate changes on cropland NH₃ emissions: We simulated cropland NH₃ emissions using Community Multiscale Air Quality model with bidirectional NH₃ exchange (CMAQ-BIDI) that involves a dynamic NH₃ air-surface exchange process driven by current and future climate fields and LC projections. Attribution analysis was conducted to separate the contributions of individual LC types and climate variables on NH₃ emission changes. The results suggested that, under RCP4.5 scenario, NH₃ emissions will increase by 11.7% and 20.4% by 2050 and 2100, respectively, due to temperature increase alone. The increase will be 17.2% and 50.4% under RCP8.5. The NH₃ emitted accounts for 3% loss of the total N applied. Future LC changes will induce the uncertainty in projecting the emissions, indicates a role of the land-based policies in mitigating the emissions. We found that mitigation measures, including replacement of urea with non-urea fertilizer, deep placement, urea application with irrigation, and usage of urea inhibitor, could reduce cropland NH₃ emissions by 16%-36% with yield gains ranging from 72 to 162 Gg N/year. Further investigation will target the relevant impacts on water quality and ecosystems using SPARROW and PnET-BGC models and involve a comprehensive cost-effective analysis.

Assessing the impacts of increased NH₃ emissions on aerosol acidity and PM levels: Focusing on aerosol acidity, the impact of future NH₃ emission change on air quality was simulated using CMAQ v5.0.2 over the continental US domain. In addition to the differences between the current (the year 2010) and the future (2050) baseline scenarios, we also tested the sensitivity of aerosol acidity to NH₃ emission changes at different SO₂ reduction levels in the future. The anticipated increase of NH₃ emissions would only result in a slight increase in particle pH, with the national average of 0.02 and a maximum of 0.25 under different SO₂ emission reduction scenarios. Most of the additional NH₃ will remain in the gas phase because of its pH-mediated semi-volatility. As a result, PM_2.5 levels only show a minimal change (<0.8%) due to NH₃ emission change. A regression of TNHx (NH₃+ NH₄) concentration change between scenarios with current and future NH₃ emission levels at different SO₂ emission reduction levels indicates that it takes about 10 times increase of TNHx concentration to increase the particle pH by one. However, in terms of chemical composition, ammonium nitrate will become the dominant aerosol species in the Midwest US when SO₂ is further reduced in the future. This indicates that future changes in agriculture NH₃ emissions will affect the air pollutant composition and the aerosol composition, but unlikely change the major pathway of aerosol formation and PM levels.

Future Activities:

Continue work on set-up and adjustment of the SPARROW and PnET-BGC models and evaluate of the relevant impacts of cropland NH₃ emissions on water quality and ecosystems; Evaluate the potential impacts of future biogenic emission changes on air quality and N deposition; conduct cost-effective analysis of mitigation measure targeting future cropland NH₃ emissions in views of not only farmland levels but also population and ecosystem levels.

Journal Articles on this Report : 2 Displayed | Download in RIS Format

Publications Views
Other project views:	All 27 publications	19 publications in selected types	All 19 journal articles

Publications
Type	Citation	Project	Document Sources
Journal Article	Henneman LRF, Shen H, Liu C, Hu Y, Mulholland JA, Russell AG. Responses in ozone and its production efficiency attributable to recent and future emissions changes in the Eastern United States. Environmental Science & Technology 2017;51(23):13797-13805.	R835880 (2016) R835880 (2017) R835880 (2018) R835880 (Final)	Abstract from PubMed Full-text: ACS-Full Text HTML Exit Abstract: ACS-Abstract Exit Other: ACS-Full Text PDF Exit
Journal Article	Lawal AS, Guan X, Liu C, Henneman LRF, Vasilakos P, Bhogineni V, Weber RJ, Nenes A, Russell AG. Linked response of aerosol acidity and ammonia to SO₂ and NO_X emissions reductions in the United States. Environmental Science & Technology 2018;52(17):9861-9873.	R835880 (2017) R835880 (2018) R835880 (Final) R835882 (Final)	Abstract from PubMed Full-text: ACS-Full Text HTML Exit Abstract: ACS-Abstract Exit Other: ACS-Full Text PDF Exit

Supplemental Keywords:

reactive nitrogen species, PM_2.5, land use change, pollutants emissions, air and water quality

Progress and Final Reports:

Original Abstract

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.