Impacts of Potential CO_2-Reduction Policies on Air Quality in the United States

摘要

Impacts of emissions changes from four potential U.S. CO_2 emission reduction policies on 2050 air quality are analyzed using the community multiscale air quality model (CMAQ). Future meteorology was downscaled from the Goddard Institute for Space Studies (GISS) ModelE General Circulation Model (GCM) to the regional scale using the Weather Research Forecasting (WRF) model. We use emissions growth factors from the EPAUS9r MARKAL model to project emissions inventories for two climate tax scenarios, a combined transportation and energy scenario, a biomass energy scenario and a reference case. Implementation of a relatively aggressive carbon tax leads to improved PM_(2.5) air quality compared to the reference case as incentives increase for facilities to install flue-gas desulrurization (FGD) and carbon capture and sequestration (CCS) technologies. However, less capital is available to install NO_X reduction technologies, resulting in an O_3 increase. A policy aimed at reducing CO_2 from the transportation sector and electricity production sectors leads to reduced emissions of mobile source NO_X, thus reducing O_3. Over most of the U.S., this scenario leads to reduced PM_(2.5) concentrations. However, increased primary PM_(2.5) emissions associated with fuel switching in the residential and industrial sectors leads to increased organic matter (OM) and PM_(2.5) in some cities.