Impacts of transportation sector emissions on future U.S. air quality in a changing climate. Part II: Air quality projections and the interplay between emissions and climate change

Patrick Campbell; Yang Zhang; Fang Yan; Zifeng Lu; David Streets

doi:10.1016/j.envpol.2018.03.016

Impacts of transportation sector emissions on future U.S. air quality in a changing climate. Part II: Air quality projections and the interplay between emissions and climate change

Environ Pollut. 2018 Jul:238:918-930. doi: 10.1016/j.envpol.2018.03.016. Epub 2018 Apr 24.

Authors

Patrick Campbell¹, Yang Zhang², Fang Yan³, Zifeng Lu³, David Streets³

Affiliations

¹ Department of Marine, Earth, and Atmospheric Sciences, NCSU, Raleigh, NC 27695, USA.
² Department of Marine, Earth, and Atmospheric Sciences, NCSU, Raleigh, NC 27695, USA. Electronic address: yzhang9@ncsu.edu.
³ Computation Institute, University of Chicago, Chicago, IL 60637, USA; Energy Systems Division, Argonne National Laboratory, Argonne, IL 60439, USA.

PMID: 29684896
DOI: 10.1016/j.envpol.2018.03.016

Abstract

In Part II of this work we present the results of the downscaled offline Weather Research and Forecasting/Community Multiscale Air Quality (WRF/CMAQ) model, included in the "Technology Driver Model" (TDM) approach to future U.S. air quality projections (2046-2050) compared to a current-year period (2001-2005), and the interplay between future emission and climate changes. By 2046-2050, there are widespread decreases in future concentrations of carbon monoxide (CO), nitrogen oxides (NO_x = NO + NO₂), volatile organic compounds (VOCs), ammonia (NH₃), sulfur dioxide (SO₂), and particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM_2.5) due mainly to decreasing on-road vehicle (ORV) emissions near urban centers as well as decreases in other transportation modes that include non-road engines (NRE). However, there are widespread increases in daily maximum 8-hr ozone (O₃) across the U.S., which are due to enhanced greenhouse gases (GHG) including methane (CH₄) and carbon dioxide (CO₂) under the Intergovernmental Panel on Climate Change (IPCC) A1B scenario, and isolated areas of larger reduction in transportation emissions of NO_x compared to that of VOCs over regions with VOC-limited O₃ chemistry. Other notable future changes are reduced haze and improved visibility, increased primary organic to elemental carbon ratio, decreases in PM_2.5 and its species, decreases and increases in dry deposition of SO₂ and O₃, respectively, and decreases in total nitrogen (TN) deposition. There is a tendency for transportation emission and CH₄ changes to dominate the increases in O₃, while climate change may either enhance or mitigate these increases in the west or east U.S., respectively. Climate change also decreases PM_2.5 in the future. Other variable changes exhibit stronger susceptibility to either emission (e.g., CO, NO_x, and TN deposition) or climate changes (e.g., VOC, NH₃, SO₂, and total sulfate deposition), which also have a strong dependence on season and specific U.S. regions.

Keywords: Climate change; Dynamical downscaling; SPEW-Trend; Technology Driver Model; Transportation sector emissions; WRF/CMAQ.

MeSH terms

Air Pollutants / analysis*
Air Pollution / analysis
Air Pollution / statistics & numerical data*
Carbon Dioxide
Carbon Monoxide
Climate Change*
Forecasting
Models, Theoretical
Nitrogen Oxides / analysis
Ozone / analysis
Particulate Matter / analysis
Sulfur Dioxide
Transportation
United States
Vehicle Emissions / analysis*
Volatile Organic Compounds / analysis
Weather

Substances

Air Pollutants
Nitrogen Oxides
Particulate Matter
Vehicle Emissions
Volatile Organic Compounds
Sulfur Dioxide
Carbon Dioxide
Ozone
Carbon Monoxide