In New England, between 1990 and 2000, we have seen a 25% decrease in NO x
emissions from all sources (from approximately 897,000 tons to 668,000 tons).
Between 2000 and 2006, NO x emissions from acid rain-affected power plants in
New England have further decreased by more than 31,000 tons. During that same
period, SO 2 emissions from those power plants have decreased by 54% (from
approximately 211,000 tons to 96, 500 tons).
During the 1990s, research has continued and gradually developed a better
understanding of acid rain and its effects on the environment. A closer look at soil
chemistry showed how acid rain has changed the balance of calcium, aluminum, and
other elements. Since acid rain makes waters acidic, it causes them to absorb the
aluminum that makes its way from soil into lakes and streams. Sulfur dioxide
pollution mostly from coal-fired power plants was causing acid rain and snow,
killing aquatic life and forests. A debate ensued: Regulation would direct all plant
owners to cut pollution by a set amount, but this method, critics argued, would be
costly and ignore the needs of local plant operators. The solution was devised to capand-trade approach, written into the 1990 Clean Air Act. It required cutting overall
sulfur emissions in half, but let each company decide how to make the cuts. Power
plants that lowered their pollution more than required could sell those extra allowances to other plants. A new commodities market was born. Sulfur emissions went
down faster than predicted and at one fourth of the projected cost. Since its launch,
cap-and-trade for acid rain has been regarded widely as highly effective at solving
the problem in a flexible, innovative way [58]. Since this first historic success, efforts
were expanded to help create new market mechanisms that account for the impact to
the environment. This solution has served as the inspiration behind one of the most
powerful tools we have to fight climate change: carbon markets [58].
The success of the Acid Rain Program has led to consideration of other programs
based on setting an emissions cap. The NO x budget program, which began in 1999,
places a limit on NO x emissions from power plants and some other sources during
the warmer months of the year. Its purpose is to control ground level ozone, but it
will have some effect on acid rain also. Massachusetts, New Hampshire, and
Connecticut have designed their own programs to further limit emissions of NO x
and SO 2 . Connecticut’s rule contributed to a 68% decrease in SO 2 emissions from
large sources from 2001 to 2002 [47].
On March 10, 2005, US EPA issued the Clean Air Interstate Rule (CAIR). This
rule provides states with a solution to the problem of power plant pollution that drifts
from one state to another. CAIR permanently capped emissions of SO 2 and NO x in
the Eastern United States. US EPA’s CAIR addressed regional interstate transport of
soot (fine particulate matter) and smog (ozone), which are associated with thousands
of premature deaths and illnesses each year. CAIR required 28 eastern states to make
reductions in sulfur dioxide (SO 2 ) and nitrogen oxide (NO X ) emissions that contribute to unhealthy levels of fine particle and ozone pollution in downwind states. Once
it was fully implemented, CAIR reduced SO 2 emissions in 28 eastern states and the
District of Columbia by over 70% and NO x emissions by over 60% from 2003 levels
[59]. CAIR was replaced by the Cross-State Air Pollution Rule (CSAPR), as of
January 1, 2015.
286
L. K. Wang et al.
emissions from all sources (from approximately 897,000 tons to 668,000 tons).
Between 2000 and 2006, NO x emissions from acid rain-affected power plants in
New England have further decreased by more than 31,000 tons. During that same
period, SO 2 emissions from those power plants have decreased by 54% (from
approximately 211,000 tons to 96, 500 tons).
During the 1990s, research has continued and gradually developed a better
understanding of acid rain and its effects on the environment. A closer look at soil
chemistry showed how acid rain has changed the balance of calcium, aluminum, and
other elements. Since acid rain makes waters acidic, it causes them to absorb the
aluminum that makes its way from soil into lakes and streams. Sulfur dioxide
pollution mostly from coal-fired power plants was causing acid rain and snow,
killing aquatic life and forests. A debate ensued: Regulation would direct all plant
owners to cut pollution by a set amount, but this method, critics argued, would be
costly and ignore the needs of local plant operators. The solution was devised to capand-trade approach, written into the 1990 Clean Air Act. It required cutting overall
sulfur emissions in half, but let each company decide how to make the cuts. Power
plants that lowered their pollution more than required could sell those extra allowances to other plants. A new commodities market was born. Sulfur emissions went
down faster than predicted and at one fourth of the projected cost. Since its launch,
cap-and-trade for acid rain has been regarded widely as highly effective at solving
the problem in a flexible, innovative way [58]. Since this first historic success, efforts
were expanded to help create new market mechanisms that account for the impact to
the environment. This solution has served as the inspiration behind one of the most
powerful tools we have to fight climate change: carbon markets [58].
The success of the Acid Rain Program has led to consideration of other programs
based on setting an emissions cap. The NO x budget program, which began in 1999,
places a limit on NO x emissions from power plants and some other sources during
the warmer months of the year. Its purpose is to control ground level ozone, but it
will have some effect on acid rain also. Massachusetts, New Hampshire, and
Connecticut have designed their own programs to further limit emissions of NO x
and SO 2 . Connecticut’s rule contributed to a 68% decrease in SO 2 emissions from
large sources from 2001 to 2002 [47].
On March 10, 2005, US EPA issued the Clean Air Interstate Rule (CAIR). This
rule provides states with a solution to the problem of power plant pollution that drifts
from one state to another. CAIR permanently capped emissions of SO 2 and NO x in
the Eastern United States. US EPA’s CAIR addressed regional interstate transport of
soot (fine particulate matter) and smog (ozone), which are associated with thousands
of premature deaths and illnesses each year. CAIR required 28 eastern states to make
reductions in sulfur dioxide (SO 2 ) and nitrogen oxide (NO X ) emissions that contribute to unhealthy levels of fine particle and ozone pollution in downwind states. Once
it was fully implemented, CAIR reduced SO 2 emissions in 28 eastern states and the
District of Columbia by over 70% and NO x emissions by over 60% from 2003 levels
[59]. CAIR was replaced by the Cross-State Air Pollution Rule (CSAPR), as of
January 1, 2015.
286
L. K. Wang et al.