Visualizing Environmental Science

markets to drive innovative solutions, policy makers in-

creasingly look to economics as part of the solution to

environmental problems.

1. Why is the National Environmental Policy
   Act the cornerstone of U.S. environmental
   law?


2. What are environmental impact statements?


3. What is the EPA’s role in environmental
   regulation?

System now totals more than 44 million hectares
(109 million acres).
s Millions of hectares of farmland particularly
vulnerable to erosion have been withdrawn from
production, reducing soil erosion by more than
60 percent.
sMany endangered species are recovering, and the
American alligator, California gray whale, and bald
eagle have recovered enough to be removed from
the endangered species list. (However, dozens of
other species, such as the manatee and Kemp’s rid-
ley sea turtle, have suffered further declines or ex-
tinction since 1970.)
Although we still have a long way to go, pollution
control efforts through legislation have been particu-
larly successful. According to the EPA’s 2008 Report on the
Environment:

sEmissions of six important air pollutants have

dropped by more than 25 percent since 1990.

(Carbon dioxide emissions, however, have contin-

ued to rise.)

sSince 1990, levels of wet sulfate, a major component

of acid rain, have dropped by 20 to 35 percent.

sIn 2007 almost 90 percent of the U.S. population

got its drinking water from community water systems

with no violations of EPA standards, up from around

75 percent in 1993 (Figure 3. 12 ).

sIn 2008 45 percent of municipal solid waste gener-

ated in the United States was combusted for energy

recovery or recovered for composting or recycling,

up from 6 percent in the 1960s.

sBy 2007 the EPA considered human exposures to

contamination to be under control at 93 percent of

the 1968 listed hazardous waste sites.

In the 1960s and 1970s, pollution was often obvious—
witness the Cuyahoga River in Cleveland, Ohio, which
burst into flames from the oily pollutants on its surface
several times. Legislators, the media, and the public typi-
cally perceive things like burning rivers as serious threats
that require immediate attention, without regard to the
cost. As the effects of global climate change become
more obvious, public pressure to develop policies to re-
duce greenhouse gas emissions have grown. Recognizing
the high costs of historical legislation and the power of

Environmental Legislation 61

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The water supply for a town or city is treated before use so it is

safe to drink. Photographed in Sarasota, Florida.

Tampa Bay Times/ZUMAPRESS.com