Geoscience Reference
In-Depth Information
the surviving forests throughout Europe. Subsequently, and in parallel with the
massive consumption of fossil fuels, the forests started to grow again during the
second half of the 20th century and today cover a surface area that is perhaps
greater than at any other period in the last millennium. The current research on
LUCC, applying GIS to historical cadastral maps and aerial photographs, might
help historians to con
rm the general trend towards a new forest transition.
99
The
study on the human appropriation of aboveground net primary production of bio-
mass (HANPP) has demonstrated that in Austria
HANPP decreased continuously
from 60 % in 1830 to 48 % in 1970 and then started to increase again slightly, up to
51 % in 1995. This means that today about 23 % more biomass (i.e., 129 PJ/yr or 7
Mt of biomass) remains in terrestrial ecosystems than in 1830
“
.
100
A more recent
study shows there was, in the United Kingdom, a HANPP decline from 74 % in
1800 down to a level of around 65 % in the late 19th and early 20th centuries,
followed by an increase up to the late 1950s and a new decline to a value of 67 % in
the year 2000.
101
Although much more research is needed on this issue, it seems
clear that up to a point past
”
could have exerted a
greater direct pressure on European forests than in more recent times, when fossil
fuels consumption has globalized ecological footprints and displaced environmental
load onto the rest of the world or the atmosphere, subject to global warming
emissions.
102
Here again the question of which driving forces underlay this trend arises.
Clearly, increasing population densities must have represented a challenge for any
'
'
advanced organic economies
'
economy. Nevertheless, deforestation must also be linked with
market networks and urbanisation, in spite of the fact that many scholars have paid
no direct attention to this. To obtain a
organic-based
'
nal energy unit of charcoal,
ve times more
rewood had to be burnt in a charcoal-burner with an energy loss of nearly 60 %.
Taking into account that fuel wood extracted from forests could have been consumed
either as
rewood or charcoal, any switching in consumption from the latter to the
former would have had considerable impact on the primary energy needed. What
then would have been the use of transforming
rewood into charcoal? The main
reason was to allow available terrestrial means of transporting heavy goods to travel
greater distances, without consuming more energy carrying the fuel than the energy
actually carried.
103
The rural population could easily obtain enough
rewood from
neighbouring forests, coppices, brushwood or wood crops and orchards. Despite the
heavy water content of wood, they could easily carry it home for short distances. But
cities needed to be provided with much greater quantities of fuel wood coming from
quite distant locations. Even the slightest increase in urbanization would have meant
99
Kov
(
1999
) and Agnoletti (
2006
).
100
Krausmann (
2001
).
101
Musel (
2008
).
102
Haberl et al. (
2001
).
103
á
ř
Sieferle (
2001
).
