The above title is taken from an article by
Steffen et al. (2007) where they discuss the existence of the Anthropocene as a
new epoch characterised by human-driven changes to the Earth System. The
authors of the study use atmospheric CO2 concentrations to track the
‘Anthropocene’ and determine whether humans have indeed had enough impact to
“overwhelm the great forces of nature”.
What
they found is that concentrations of CO2 in the atmosphere have risen from
279ppm (during the pre-industrial era) to 379ppm in 2005 (now the value is
estimated to be 393ppm - co2now.org). This is significant due to the fact that
concentrations had only been between 260 and 285ppm throughout the Holocene.
Thus, they take the beginning of the Anthropocene to be the beginning of the
1800s. Others disagree, which we will look at another time, but anyhow the
results show that humans have indeed had a significant impact on the Earth
System. What we want to know now is the story behind it and how it links to the
notion of overpopulation.
The
story that is told is that we have always affected our surroundings, but this
has evolved from localised impacts as hunter-gatherers (for example with the
use of fire) to having impact on a global scale after the industrial
revolution. During the late Pleistocene megafaunal extinction, although there
are debates about the effect of climate, it is clear that humans had a role to
play, through predation. When humans began domesticating, this was affecting
their environment on a larger scale, although Steffen et al. maintain it wasn’t
on a large-enough scale to alter the ‘great forces of nature’. The turning
point, though, was the onset of industrialisation in the post-Enlightenment
era.
Previously,
economic and population growth were constrained by energy limitations. This was
because wind and water power are only available in certain locations and under
certain conditions; the energy from plants was limited by land area and also
the inefficient conversion of light energy into chemical energy through photosynthesis
(less than 1%). However, the invention of the steam engine in the 1770s and
1780s by Watt, coupled with the increased usage of fossil fuels shattered this
bottleneck. The Haber-Bosch synthesis – which allowed for the synthesis of
fertiliser out of atmospheric nitrogen) along with improved medical care meant
that the population began to grow exponentially and along with it all the
activities that increased CO2 production (refer to the graphs above). This
trend has continued, unabated except for the Great Depression and the World
Wars, until present day.
The
main point I wanted to take from this article was that humans do have an impact
on the environment; there is no doubt that, and the larger the human population,
the larger the impact. Although Steffen et al. are implying that it is energy
consumption, and economic growth that cause CO2 concentrations to rise, it
follows logically that with less humans around, there would simply be less of the
activities that impact the Earth System.
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