3. Adaptation and coping options in the silviculture
sector
Actions in the silviculture sector have signi®-
cant potential as response options to reduce global
warming by maintaining or increasing carbon
stocks in plantations and wood products and, in
the case of charcoal used in Brazil's iron and
steel industry, through fossil fuel substitution [21].
The potential of silviculture is more limited, however,
for adaptation, or coping in the sense of
getting along with climatic change, rather than as
a means of ®ghting against it.
Societies can adapt to change by altering the
productive activities they pursue to support their
populations. If climatic change renders certain
Fig. 6. Response of yields and area of short-rotation plantations to the percent of precipitation decline resulting from climatic
change by the year 2050: (A) Response expressed in absolute amounts. (B) Response expressed as percentage deviation from the no
climatic change scenario.
P.M. Fearnside / Biomass and Bioenergy 16 (1999) 91±102 99
areas less appropriate for the agricultural or
other use they formerly had and more appropriate,
for example, for a silvicultural plantation,
then a switch to forestry will be the likely outcome.
Even if the climatic conditions at the site
in question remain completely unchanged, climatic
changes elsewhere may alter the relative
prices of the dierent commodities that might be
produced, leading to a decision to use land for
forestry rather than, say, for pasture or annual
crops. Climatic change, of course, may not be
the only or even the principal cause of such
shifts: markets for products of plantation forestry
can be expected to increase in the future as a
result of the continued human destruction of
mature native forests in the tropical, temperate,
and boreal zones.
Rapid tree growth, low land prices, and low
labor and tax costs in tropical locations make
them likely sites for plantation expansion, including
plantations subsidized with funds from carbon-oset
programs intended to avert climatic
change elsewhere in the world. Conversion of
land to plantations can deprive local populations
of their means of support [22]. In the case of
plantations for charcoal, the industry's competitiveness
depends on maintaining most of the
labor pool under conditions of extreme poverty.
Expansion into drier areas, as in the Northeast,
would be likely to favor drought-resistant species
such as E. camaldulensis that are more suitable
for charcoal than for pulp; any climatic change
leading to drier conditions in the existing plantation
area would favor the same species shifts and
social consequences. Mechanisms are needed to
insure that plantation establishment, especially
when ®nanced as a carbon oset, is only encouraged
where it is bene®cial [23].
Among the eects of subsidizing plantation
expansion would be increasing supplies of wood
products beyond the levels they would otherwise
reach, with consequent lowering of prices in
Brazil and in the countries to which Brazil
exports. The macroeconomic impacts of this
would be many. Unsubsidized competitors would
clearly sustain losses. Any reduction in plantation
and wood product pools elsewhere by the losers
in this competition would reduce the net carbon
bene®ts of the plantation subsidy program.
Evaluation of these and other rami®cations of
carbon-oset proposals in silviculture are needed
before major initiatives are undertaken.
The ultimate coping mechanism in tropical
countries, as well as for the globe as a whole,
will be to adjust human population and consumption
levels to the carrying capacity of the
land. Many climatic changes entail reduction of
productive capacity and, on a global scale, will
demand diversion of hundreds of billions of dollars
in resources to activities intended merely to
substitute for natural climate regulation mechanisms
and keep the world's environment and
human infrastructure at a state roughly equivalent
to what we have today for free. Capital, land,
and human resources allocated to response
options, including forestry initiatives such as
plantations motivated by carbon considerations,
will not be available for producing food and
other necessities. The carrying capacity of the
world as a whole will be lower than it would be
without climatic change; reductions will be
greater in some countries than in others, and in a
few instances countries may bene®t from more
favorable climate.
Human population numbers and levels of consumption
must eventually come into balance with
the carrying capacity of each country.
Particularly in tropical forest countries, carrying
capacities for human populations are lower than
many have been led to believe [24]. The process
of adjustment to carrying capacity limits is likely
to be a painful one even without the added strictures
imposed by climatic change. The challenges
these adjustments pose must be faced with even
greater speed in light of impending climatic
changes: policies aecting population and consumpti