Introduction – humans, nature and human nature - Ecological Applications: Toward a Sustainable World - page 4

Fig. 1.1 Growth of the
world's human
population since 1750
and predicted growth
until 2050 (solid line).
The histograms
represent population
increments for each
decade. The decadal
increments are
predicted to get smaller,
but the overall
population continues to
grow. (After United
Nations, 1999.)

100 10

Population
increment

80

8

60 6

40

4

Population
size

20

2

0

0

1750 1800 1850 1900 1950 2000 2050

wild mammals combined. We are not unique in destroying habitat and contaminat-
ing the environment. But we are distinctive in using fossil fuels, water and wind
power, and nuclear fi ssion to provide energy for our activities. These technologies
have provided the power to transform much of the face of the planet through urbani-
zation, industrial development, mining, and highly intensive agriculture, forestry
and fi shing. The loss of habitats and the degradation of what remains are responsible
for driving a multitude of species to the verge of extinction. Beavers, prairie dogs
and crayfi sh may fundamentally alter the habitats in which they live, but the bur-
geoning population of Homo sapiens , with attendant technologies, has spread to
every continent. The consequences are both intense and widespread, leaving few
hiding places for pristine nature to thrive.
Many environmental effects are caused locally, although the same patterns are
repeated across the globe (pollution by fertilizers and pesticides, the spread of invad-
ers, and so on). In one very important case, however, the scale of the problem is
itself global - climate change resulting from an increase in atmospheric carbon
dioxide (produced by burning fossil fuels) together with other 'greenhouse' gases.
You w ill discover that this global pollution problem has implications for every other
environmental management issue.
The remainder of this chapter focuses on the scale of human impacts on biological
diversity (and the consequences for human welfare - Section 1.2), as well as the
knowledge that needs to be harnessed for a sustainable future (Section 1.3). This
will form the backdrop to the remainder of the topic where, chapter by chapter and
topic by topic, I explore how ecological knowledge can be applied to remedy the
problems we have caused.

1.2 A biodiversity
crisis

It is important to be clear about the meaning of biodiversity , and its relationship to
species richness . Species richness is the total number of species present in a defi ned
area. At its simplest, biodiversity is synonymous with species richness - and this is
generally how I will use it. Biodiversity, though, can also be viewed at scales smaller