2. Oxidants

Contemporary Issues in Environmental Assessment


Deforestation is intimately linked to carbon dioxide release, climate change, acid rain, and extinction of plant and animal species. Deforestation not only contributes to the greenhouse effect, but also destroys the long-term ability of the land and forest resources to meet human needs, and inhibits the development of viable local economies. The loss of plant and animal species due to loss of forest habitat is hard to quantify, but this represents an irreversible loss of resources to the world, as well as to the local peoples.

Forests are an important economic resource for many regions of the United States. Any reduction in timber harvesting, no matter how justified on environmental grounds or overall economic grounds, is going to meet with strong opposition. Often, the very livelihood of a large proportion of the regional population depends upon the timber-harvesting industry; in many cases forests are tended as slow-growing crops on small or large tree farms. In areas that are relatively scenic or pristine the ultimate losses due to reduced aesthetic and tourism values also may be serious.

Industrialized Countries

Deforestation in industrialized countries is not usually a major economic problem. Impacts on forests due to acid rain, photochemical oxidants, overharvesting, and changed land use are not well understood. Most industrialized countries are able to make the necessary economic tradeoffs and manage forest resources effectively. Regional problems related to efforts to control timber harvesting to a renewable level are manageable, and some long-term policy options (as discussed later in this section) can be developed to balance economic and environmental requirements.

Newly Industrializing Countries

Problems of deforestation in newly industrializing countries are serious and environmental and economic consequences significant. Of the world’s annual carbon dioxide release due to deforestation, 40 percent was contributed by tropical South America, 37 percent by tropical Asia, and 23 percent by tropical Africa. Five countries accounted for half of the total: Brazil, Colombia, Indonesia, Côte d’Ivoire, and Thailand (Postel, 1988). By the late 1980s, 45 countries around the equator that were practicing aggressive forest clearing destroyed 20 to 40 hectares every minute (Gradwohl & Greenberg, 1988). Clearing for crops, fuel wood, cattle ranching, and commercial timber harvest destroyed 39 million acres annually (Postel, 1988). Fortunately, the pace of deforestation seems to be slowing at the global level as well as in newly industrializing regions: The estimate of forest cover change globally indicates an annual loss of 5.21 million hectares (Mha) between 2000 and 2010, compared with 8.33 Mha between 1990 and 2000 and 15.5 Mha between 1980 and 1990 (Marcoux, 2000; Food and Agriculture Organization, 2010).

Tropical deforestation is driven by poverty, traditional practices, national development policies, and foreign debts. Much of this cleared land is unsuitable for the monocrop agricultural practices being adopted, and becomes barren within one to two crop seasons. Lands cleared for pasture may support livestock for only 5 to 10 years. Once forests are removed, rural people are unable to meet their pressing need for fuel wood, and soil erosion, floods, and drought become more severe. Forest regeneration on cleared lands is largely unsuccessful due to the lack of natural seed, predators that feed on the seeds and seedlings, and the hot, dry conditions of tropical pasture land compared to the forest environment.

Brazil, the site of 30 percent of the world’s tropical forest area, alone contributes one-fifth of the total carbon dioxide emissions from deforestation. Although the annual release has been estimated at 336 million tons, 500 million tons of carbon dioxide were released in 1987 (Postel, 1988). Government programs are unfortunately responsible for most of this deforestation. Brazil’s current problems have roots in the decision of the 1960s to provide overland access to Amazonia before there was adequate understanding of the resources available and how they could be developed in a sustainable manner.

Beginning in the 1960s, the Brazilian government undertook major road-building programs to open the Amazon, followed by subsidized settlement. In the 1970s subsidized programs for large-scale export projects in livestock, timber, and mining were initiated; 72 percent of the tropical forests altered up to 1980 were due to cattle-ranching efforts. Despite subsidies and tax incentives, the supported livestock projects have performed at only 16 percent of what was expected because cattle ranching in this environment is intrinsically uneconomic (Mahar, 1990). The government also supports a policy that considers deforestation as evidence of land improvement and thus gives the tenant rights of possession, which can both then be sold. In 1989, a program was initiated to end subsidies for new livestock projects, and may support agro-ecological zoning for the country.

Policy Options

As discussed earlier, forestry management in developed countries, where serious and ongoing deforestation is not a major problem, need only to focus on some long-term market-economy-based policies. Increasing total forested area and ending subsidies that support logging are two policy options. For example, the 13 million hectares of marginal U.S. cropland that have been set aside in the Conservation Reserve Program, if reforested, could absorb 65 million tons of carbon annually until the trees mature, reducing U.S. carbon emissions by 5 percent (OTA, 1991). Federal subsidies of below-cost timber sales in remote areas of national forests promote excessive timber cutting and cost billions in the early 1990s (Wirth & Heinz, 1991). Efforts to increase the productivity of forests and to plant and manage trees as a renewable biomass energy source are other possibilities for U.S. policy. Some regional issues related to economic impacts of reduced timber harvesting are important and would require creative, region-specific policy options.

Slowing deforestation in Third World countries will require the financial and technical support of industrial nations to ease their international debt burden and to assist them in developing sustainable economies. Developing countries are encouraged by their debt burden to exploit forests for quick economic gain. “Debt-for-nature swaps” were devised by the World Wildlife Fund science director Thomas Lovejoy in 1984 as an innovative approach to this problem: a nongovernmental organization (e.g., The Nature Conservancy) purchases a portion of the debt and then donates the debt instrument to the country’s bank in exchange for environmentally appropriate action. Swaps of millions of dollars contribute much-needed funds for environmental programs, but have little impact on national debts measured in tens or hundreds of billions of dollars.

A policy option for developed countries may be to require industry to make equal investment in reforestation whenever a carbon-emitting project is undertaken. A joint venture between Applied Energy Services, World Resources Institute, and CARE was planned to offset carbon emissions from a coal-fired power plant in Connecticut with forestation in Guatemala. Twelve thousand hectares of woodlot and 60,000 hectares of combined trees and crops were to be planted, to be harvested on a sustainable basis. Large-scale forestation programs face the difficulties of locating and financing the purchase of suitable land and gaining cooperation from local governments. However, as an example, this project was relatively inexpensive ($16.3 million) because land would not be purchased, and workers and families to benefit from the planting would not be paid (Flavin, 1990).

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