Geoscience Reference
In-Depth Information
The human clearance of forests may represent an important historical marker in the history of the
Anthropocene. The palaeoclimatologist William Ruddiman has argued that it is not the rise of modern
industry that marks the beginning of the human geological era, but the emergence of widespread
deforestation. In his book Plows, Plagues, and Petroleum, Ruddiman (2005) develops what has been
termed an 'early' or 'long Anthropocene' hypothesis. According to Ruddiman there is a distinct
pattern to the changing concentrations of greenhouse gases in the Earth's atmosphere since the
last ice age (some 11,000 years ago). While in previous ice ages levels of carbon dioxide and methane
reached a climax just after the ice age and then declined, in the Holocene something different has
happened. While levels of greenhouse gases did fall for around 3000 years, they then started to rise
and have continued to do so ever since. Clearly these recorded rises in atmospheric carbon dioxide
and methane levels cannot all be attributed to modern industrialization, which really only began
some 200 to 300 years ago. According to Ruddiman's long Anthropocene hypothesis, the reason
that the current inter-glacial period has seen a long-term trend in rising levels of greenhouse gases
can only be attributed to the rise of agricultural society. The large-scale forest clearances associated
with the emergence of agriculture resulted in a significant reduction in the planet's natural capacity
to absorb and store carbon dioxide. In addition to this, Ruddiman connects the emergence of rice
cultivation some 5000 years ago with rapid increases in global levels of methane (the wet and warm
conditions associated with rice paddies are ideal for the process of methanogenesis).
Ruddiman's hypothesis has been challenged by some (see Peterson, 2008). Counter arguments
claim that too few people were involved in agriculture 8000 years ago to account for the increases
in greenhouses gases observed. It is also claimed that there is no real norm in the pattern of
greenhouses gas levels in past glacial and inter-glacial periods, so it is problematic to claim that
our current situation is necessarily unique (Peterson, 2008).
Key readings
Ruddiman, W.F. (2001) Earth's Climate: Past and Future, W.H. Freeman and Co, NY
Ruddiman, W.F. (2005) Plows, Plagues, and Petroleum, Princeton University Press, Princeton
of MDF products in China and the UK. MDF, or
medium-density fibreboard, is an engineered
wood product that is comprised of hardwood and
softwood residuals. MDF is commonly used to
produce household furniture and shelving.
What
Figures 5.1
and
5.2
reveal is that over the last
17 years China has been rapidly increasing its
production of MDF, while the UK has seen a
significant increase in the levels of MDF that it
imports into its domestic market. What these
figures ultimately reveal is an emerging global
market in MDF products. This market is based
upon rapid deforestation in countries such as
China, and the associated relocation of multi-
national wood manufacturing facilities to such
low-cost locations. This market is also, however,
based upon a growing consumer market for
such wood products within more economically
developed countries, such as the UK. It is in
this context that understanding the forces now
driving deforestation requires an appreciation
of the nature of globalization and corporate
environmental relations.
