increase by ;50% in the next 50 years or so, ;90%
of the increase will be in developing countries, and as
much as 60% of the population may reside in urban
centers (WRI 1997).
In the United States, the pattern of population growth
continues to be stronger in most of the western and
southern states, while the national population is expected
to increase by 27% from 275 million in the year
2000 to 350 million by year 2030 (U.S. Department of
Commerce 1997). All states will have more people but
in some states the increases will be significant (Fig. 1).
California, Texas, and Florida will gain .6 million
persons, while 12 states (all in the West with one exception)
will experience .4% increase in population
size. Thus, although the per capita rate of population
growth in the United States is relatively low, the number
of individuals to be added to the population in
coming decades is substantial. All but one of these
states already experience severe water-based environmental
challenges.
Resource use.—The distribution of major land uses
in the United States reflects a complex pattern of historical
conversion of native lands, especially forests
and grasslands, to human-dominated lands (Turner et
al. 1998, Dale et al. 2000). The area occupied by forests
continues to decline even though large-scale conversion
to agriculture has diminished. This continued decline