Geoscience Reference
In-Depth Information
Chapter 2 discusses major factors that lead to environmental change and
some of the persistent challenges that EPA will likely continue to face in the
coming decades. The committee cannot predict with certainty what new envi-
ronmental problems EPA will face in the next 10 years or more, but it can iden-
tify some of the common drivers and common characteristics of problems. The
specific topics discussed in this chapter were identified based on committee ex-
pertise and a review of the scientific literature. This chapter is not meant to be an
exhaustive list of all factors leading to environmental changes or of all persistent
and future environmental challenges. Instead, the chapter is meant to provide
some illustrative examples of the types of problems facing EPA today and some
of the factors that create and influence those problems.
MAJOR FACTORS LEADING TO ENVIRONMENTAL CHANGE
Major socioeconomic factors are directly and indirectly driving environ-
mental changes and are increasing the imperative for EPA to maintain and
strengthen its environmental research efforts. Those socioeconomic factors are
often reflected in population growth and migration, demographic shifts, land-use
change and habitat loss, increasing energy demand and shifting energy supplies,
new consumer technologies and consumption patterns, increasing emissions of
greenhouse gases, and movement of organisms beyond their traditional ranges,
which in turn have implications for the scientific knowledge that is required to
inform policy decisions at EPA effectively. EPA will be challenged in coming
years to adapt to rapid changes in scientific knowledge, society, and the envi-
ronment. An increased awareness of the effects of human activity on human
health and the environment has raised people's concern regarding the issues that
the agency is charged with addressing.
Population Growth
It took until 1800 AD for mankind to reach a population of 1 billion peo-
ple, but only required 123 more years to reach 2 billion, 33 more years to reach
3 billion, and about 13-14 more years for each additional billion people thereaf-
ter (UN 1999). In October 2011, the worldwide population hit 7 billion (UN
2011). With the dramatic increase in population, human activities have altered
and will continue to alter an ever-increasing portion of Earth's surface (Wulder
et al. 2012). Such activities have diminished natural ecosystems and the benefits
that they provide, including water purification, flood control, climate modera-
tion, and new crop plants.
In the United States, the population continues to increase at approximately
1% per year (US Census Bureau 2012). This population growth contributes to
such environmental effects as increased emissions of greenhouse gases due to
energy use, transportation demand, and residential and commercial activities
(EPA 2011a); increased consumption of resources (Worldwatch Institute 2011);
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