| Home > Impacts of potential CO<inf>2</inf>-reduction policies on air quality in the United States |
Impacts of emissions changes from four potential U.S. CO<inf>2</inf> 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<inf>2.5</inf> air quality compared to the reference case as incentives increase for facilities to install flue-gas desulfurization (FGD) and carbon capture and sequestration (CCS) technologies. However, less capital is available to install NO<inf>X</inf> reduction technologies, resulting in an O<inf>3</inf> increase. A policy aimed at reducing CO<inf>2</inf> from the transportation sector and electricity production sectors leads to reduced emissions of mobile source NO<inf>X</inf>, thus reducing O<inf>3</inf>. Over most of the U.S., this scenario leads to reduced PM<inf>2.5</inf> concentrations. However, increased primary PM<inf>2.5</inf> emissions associated with fuel switching in the residential and industrial sectors leads to increased organic matter (OM) and PM<inf>2.5</inf> in some cities. © 2015 American Chemical Society.