Clear Skies would protect public health and the environment by improving
air quality, decreasing exposure to fine particles and ozone, and reducing
deposition of sulfur, nitrogen, and mercury.
In 2010, early reductions in fine particle and ozone levels under Clear
Skies would result in 7,800 fewer premature deaths and $55 billion
in annual health and visibility benefits nationwide each year.
Under Clear Skies, each year, by 2020, Americans would experience approximately:
- 14,100 fewer premature deaths;
- An alternative estimate projects 8,400 fewer premature deaths.
- 8,800 fewer cases of chronic bronchitis;
- 30,000 fewer hospitalizations/emergency room visits for cardiovascular
and respiratory symptoms; and
- 12.5 million fewer days with respiratory illnesses and symptoms,
including work loss days, restricted activity days, and school days.
The monetized benefits of Clear Skies would total
approximately $113 billion annually by 2020, substantially outweighing
the annual costs of $6.3 billion. This includes:
- $110 billion dollars in health benefits;
- An alternative estimate projects annual health benefits of
- $3 billion in benefits from improving visibility at select
National Parks and Wilderness Areas.
This does not include the many additional benefits that cannot currently
be quantified but are expected to be significant, including the health
benefits associated with reduced exposure to mercury and ecological
benefits associated with reductions in acid rain and coastal eutrophication.
Clear Skies would help states meet the National Ambient Air Quality
Standards (NAAQS). By 2020, based on initial modeling,
Clear Skies is expected to:
- bring 35 additional eastern counties, home to approximately 12 million
people, into attainment with the new fine particle standard (beyond
what is expected from existing programs in 2020).
- bring 3 additional counties, home to approximately 6 million people,
into attainment with the new ozone standard (beyond what is expected
from existing programs in 2020).2
- The counties remaining out of attainment are expected to move closer
to attainment, providing health benefits to the people who live there.
- Under Clear Skies and existing programs, most counties would meet
the fine particle and ozone standard by 2020.
By 2020, Clear Skies, along with implementation of existing programs,
would achieve many environmental improvements. Compared with existing
- Nitrogen deposition (one component of acid deposition) would be
reduced over much of the Eastern U.S., including sensitive coastal
areas, by up to 35% across most of the country with larger reductions
in many areas.;
- Fine particle concentrations in large portions of the East and Midwest
would be reduced by up to 25%;
- In a large portion of the East and Midwest, visibility would be
improved by 2-3 deciviews from current levels (a one deciview improvement
is a perceptible change).
- Sulfur deposition (one component of acid deposition) would be reduced
over much of the Eastern U.S., including sensitive areas, by 30-60%;
- Many areas would see large decreases in mercury deposition of 15-60%,
including the mid-Atlantic, many parts of the Southeast and Northeast,
and southeastern Michigan; and
- Chronic acidity -- the most serious form of acidification -- would
be eliminated in the Adirondacks and virtually eliminated in other
Northeastern lakes. The long-term decline in stream condition in the
Southeast would be slowed.
The figure above
presents results for chronic acidity only in modeled
lakes. As such, model results apply to a subset
of lakes in the Adirondacks and cannot be generalized
to all waters in that area.
These results do
not include lakes that experience episodic acidification,
or short periods of low Acid Neutralizing Capacity
or high acidity, during storms or snowmelt.
A significant proportion
of Adirondack lakes could still experience episodic
acidification at levels potentially harmful to fish
and other aquatic species.
Detailed Benefits Information
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B of the 2003 Clear Skies Technical Package (PDF, 49 pp.,
This document features an in-depth analysis of the expected benefits of Clear
Skies. It includes maps and information on the improvements in human health
and the environment that would be achieved with Clear Skies. This document
also includes monetized benefits.
Technical Addendum: Methodologies for
the Benefit Analysis of the Clear Skies Act of 2003 (PDF,
This document details the methods used to analyze the benefits of the Clear
Skies Act of 2003 and presents the results of the analysis. It quantifies the
health and visibility improvements that would be achieved by Clear Skies and
projects the monetary value of those improvements.
Overview of the Human
Health and Environmental Effects of Power Generation: Focus on Sulfur
Dioxide (SO2), Nitrogen Oxides (NOx) and Mercury (Hg) (PDF,
15 pp., 1.1MB)
Clear Skies is intended to reduce the health and environmental impacts of power
generation. This document summarizes the effects of power generation, particularly
those associated with sulfur dioxide (SO2), nitrogen oxides (NOx), and mercury.
This document does not address the specific benefits of Clear Skies.
Related Environmental and Health Information
Clean Air Interstate
Air Quality Trends
National Ambient Air
and Hot Spots (PDF, 17pp., 17.3MB)
1The two sets of estimates
reflect alternative assumptions and analytical approaches regarding
quantifying and evaluating the effects of airborne particles on public
health. All estimates assume that particles are causally associated
with health effects, and that all components have the same toxicity.
Linear concentration-response relationships between PM and all health
effects are assumed, indicating that reductions in PM have the same
impact on health outcomes regardless of the absolute level of PM in
a given location. The base estimate relies on estimates of the potential
cumulative effect of long-term exposure to particles, while the alternative
estimate presumes that PM effects are limited to those that accumulate
over much shorter time periods. All such estimates are subject to a
number of assumptions and uncertainties. It is of note that, based on
recent preliminary findings from the Health Effects Institute, the magnitude
of mortality from short-term exposure (alternative estimates) and hospital/ER
admissions estimates (both estimates) may be overstated. The alternatives
also use different approaches to value health effects damages. The key
assumptions, uncertainties, and valuation methodologies underlying the
approaches used to produce these results are detailed in Technical
Addendum: Methodologies for Benefit Analysis of the Clear Skies Initiative,
2003. (PDF, 86 pp., 1.7MB)
2 This analysis shows
the counties that would come into attainment due to Clear Skies alone
in 2020. Additional federal and state programs are designed to bring
all counties into attainment by 2017 at the latest. Clear Skies is not
expected to bring additional counties into attainment for 2020 in the
West. Therefore, the Western region is not presented here.