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27
Deforestation
Deforestation through logging, burning, and clearing cultivation
and pasturing (Smithsonian Institution/International Hardwood
Products Association, 1990) is occurring rapidly in the tropics and
involves heavy social and ecological costs, especially where the
forests are cleared by burning, which releases CO2, CH4, and
other greenhouse gases. Deforestation rates for the 1980s are
uncertain: rates change rapidly, satellite coverage is spotty, and
substantial (and expensive) verification is required. The best
available analyses suggest many reasons for trying to limit the
rate of deforestation, one of them being that deforestation
accounts for 20 percent of the worldwide anthropogenic contribution
to greenhouse warming (World Resources Institute, 1990). Where
forests must be used, the goal is to practice what is called
"sustainable forestry," in which harvesting practices maintain the
forests and protect soil, water, wildlife, and future
resources.
Recent Trends
Figure 27.1 illustrates how emissions of carbon to the
atmosphere due to deforestation and changing land use have varied
over time on the major continents (Dale et., 1991). The estimates
are based on recent calculations by Houghton and Skole (1990) and
Houghton (1991). Forests are cut for a number of reasons, including
to provide land for agriculture and wood for wood products and
fuel. Although the rate of deforestation in temperate areas is
currently low, the deforestation of tropical countries is
continuing. At one time, Europe and North America were experiencing
net deforestation, but today this is negligible due to a number of
factors, including resource depletion and sustainable management of
what remains. A factor that has reduced pressure on remaining
forests has been the movement of
Page 425
FIGURE 27.1 The annual net flux of carbon from
the major continental areas.
Source: Dale et
al. (1991).
population from rural to urban areas due to overall economic
growth and the expansion of nonagricultural jobs. It should be
noted, however, that because of industrialization, acid rain and
other air pollutants are a serious threat to forests in some
temperate areas (World Resources Institute, 1985).
On the other hand, deforestation in many developing countries is
believed to be increasing. As shown in Figure 27.2, recent
estimates of tropical deforestation are larger than the 1981 to
1985 projection of the U.N. Food and Agriculture Organization. As
indicated in both this figure and Figure 27.1, deforestation
estimates very tremendously; it is not clear whether estimation
techniques have changed or the rate of deforestation has increased.
Table 27.1 shows the rate of deforestation for a number of
developing tropical countries (World Resources Institute,
1990).
Emission Control Methods
Recently, a number of tropical forestry experts met to discuss
the causes of tropical deforestation and what could be done to slow
deforestation. They arrived at a number of conclusions, some of
which are summarized below (Smithsonian Institution/International
Hardwood Products Association, 1990):
Page 426
FIGURE 27.2 Area of closed forests cleared
annually in selected tropical Countries, 1980s (in thousand
hectares).
(See Table 27.1 for the total of all tropical forest
clearing.)
Source: World Resources Institute (1990).
• Tropical forests will be preserved only if they are
accorded economic value.
• Blanket bans and embargoes (in contrast to selective
ones) on tropical hardwood will tend to depress the value of these
hardwoods and the forests that contain them. Such constraints
generally diminish the economic incentives to conserve and manage
these forests in the face of alternative land uses that lead to
their destruction.
• In areas where prices received for timber do not fully
cover the cost of forest management, there is a lack of incentive
and commitment to forest management.
• Funds obtained from products of the tropical forests must
be rechanneled into managing and regenerating those forests.
• The international tropical timber industry should
encourage the continued establishment of conservation areas solely
dedicated to forest preservation
It is a challenge to understand the costs of limiting tropical
deforestation and to finance such efforts.
The Conservation Foundation (CF), World Wildlife Fund (WWF), and
Fundacion Neotropica (FN) have proposed development of a ''forestry
fund" through the use of conservation endowments (Conservation
Foundation, World Wildlife Fund, and Fundacion Neotropica, 1988). A
conservation endowment
Page 427
TABLE 27.1 Deforestation of Closed Tropical Forests in
Selected Countries
Country
FAO Annual Estimate 1961–1985 (thousand
hectares)
Annual Rate of Loss Based on FAO Estimate (%)
WRI Estimate 1987 (thousand hectares)
Annual Rate of Loss Based on WRI Estimate (%)
Brazil
1,480
0.4
4,500a
2.2
Cameroon
80
0.4
100
0.6
Costa Rica
65
4.0
124
7.6
India
147
0.3
1,500
4.1
Indonesia
600
0.5
900
0.8
Myanmar (Burma)
105
0.3
677
2.1
Philippines
92
1.0
143
1.5
Thailand
379
2.4
397
2.5
Viet Nam
65
0.7
173
2.0
TOTAL
3,013
1.8
12,914
2.6
Total, all
11,400
20,400
tropical
countries
NOTE: Closed forests have trees covering a high
proportion of the ground and grass does not form a continuous layer
on the forest floor. Open forests have trees interspersed with
grazing land. One thousand hectares (ha) is 10 km2.
aThe World
Resources Institute's original estimate of 8000 was based on 1987,
which exhibited extremely anomalous conditions. Subsidies were
scheduled for removal in 1988, driving up clearing, and a drought
contributed to unusually high loss to fires. The total
deforestation for the period from 1979 to 1989 has been estimated
at 25 million hectares. The greatest deforestation occurred in
1987, and the rate in the latter half of the 1980s is probably
closer to 4 million hectares per year. The actual deforestation is
probably between 4 and 5 million hectares per year. No precise
numbers are available.
SOURCE: World Resources Institute (1990, p.
103).
would provide a stable source of funding for long-term technical
assistance and would support efforts to manage existing forest
resources and to reforest degraded areas. Of particular interest
are the portions of the plan that would attempt to (1) stop
deforestation of currently protected areas such as parks and
reserves through improved protection and management and (2) slow
logging and clearcutting on private lands by providing technical
assistance and incentives for both farmers and the commercial
