emissions increase under Alternative 6. Across all criteria pollutants, action alternatives, and
analysis years, the smallest increase in emissions is 0.1 percent and occurs for SO2 under
Alternative 7 in 2025; the largest increase is 12 percent and occurs for VOCs under Alternative 1
in 2050.
Under each action alternative in 2025 compared to the No Action Alternative, decreases
in emissions would occur for all toxic air pollutants except for DPM, for which emissions would
increase by as much as 2 percent. For 2025, the largest relative decreases in emissions would
occur for 1,3,-butadiene, for which emissions would decrease by as much as 0.5 percent.
Percentage reductions in emissions of acetaldehyde, acrolein, benzene, and formaldehyde would
be less. Under each action alternative in 2035 and 2050 compared to the No Action Alternative,
increases in emissions would occur for all toxic air pollutants. The largest relative increases in
emissions would occur for DPM, for which emissions would increase by as much as 9 percent.
Percentage increases in emissions of acetaldehyde, acrolein, benzene, 1,3,-butadiene, and
formaldehyde would be less.
In addition, the action alternatives would result in increased incidence of PM2.5-related
adverse health impacts due to the emissions increases. Increases in adverse health outcomes
include increased incidences of premature mortality, acute bronchitis, respiratory emergency
room visits, and work-loss days. In 2025 and 2035, all action alternatives except for Alternative
6 would result in increased adverse health impacts nationwide compared to the No Action
Alternative as a result of increases in emissions of NOx, PM2.5, and DPM. The increases in
adverse health impacts are largest for the least stringent alternative (Alternative 1). The
increases get smaller from Alternative 1 to Alternative 4, get larger from Alternative 4 to
Alternative 5, then smaller from Alternative 5 to Alternative 6, and larger again from Alternative
6 to Alternative 7. In 2050, all action alternatives would result in decreased adverse health
impacts nationwide compared to the No Action Alternative as a result of decreases in emissions
of SOx. The decreases in adverse health impacts get smaller from Alternative 1 to Alternative 7.
The action alternatives would increase U.S. passenger car and light truck fuel
consumption and CO2 emissions compared with the No Action Alternative, resulting in minor
increases to the anticipated increases in global CO2 concentrations, temperature, precipitation,
and sea level, and minor decreases in ocean pH that would otherwise occur, as described below.
They could also, to a small degree, increase the impacts and risks of climate change. Uncertainty
exists regarding the magnitude of impact on these climate variables, as well as to the impacts and
risks of climate change. Still, the impacts of the action alternatives on global mean surface
temperature, precipitation, sea level, and ocean pH would be extremely small in relation to
global emissions trajectories. This is because of the global and multi-sectoral nature of climate
change. These effects would be small, would occur on a global scale, and would not
disproportionately affect the United States.
According to the FEIS, passenger cars and light trucks are projected to emit 85,900
million metric tons of carbon dioxide (MMTCO 2) from 2021 through 2100 under the No
Action Alternative. Alternative 1 would increase these emissions by 10 percent through 2100
(approximately 8,800 MMTCO2). Alternative 7 would increase these emissions by 4 percent
through 2100 (approximately 3,100 MMTCO2). Emissions increases would be highest under

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