Mitigation Analysis

Greenhouse Gas Emissions

Agriculture and pasture activities have affected large areas of forest in the country. Logging in itself is not considered to be a major cause of deforestation because wood production is based on a few species and trees are harvested selectively. However, logging leads indirectly to deforestation as the forest areas are opened up through road construction and consequently subject to further intrusion by agricultural colonists.

The annual rate of forest clearing in Venezuela has not been consistently documented. Although national statistics report annual data on legal clearcutting for most regions, remote areas are usually not included. Additionally, as is common in most tropical countries, an unknown amount of illegal clearcutting is believed to contribute significantly to the depletion of forest lands. Rough estimates have provided a wide range of annual forest clearing, from less than 200,000 ha/yr (Matute, 1984) up to 600,000 ha/yr (FAO, 1993).

Because of the lack of a national study on land use change, we used various sources of information to determine the more reliable average deforestation rate that we needed in order to estimate GHG emissions from forest clearing (CVCC, 1995). Based on analysis of various data sources, we determined that on average approximately 517,000 ha of forest were cleared each year during the last decade. The primary data source was a detailed deforestation study based on multitemporal analysis of satellite images between 1973 and 1988, which covered an important area of forests that have experienced extreme land use changes (Catalan, 1993). Table IV.1 provides a summary of the average cleared area by type of forest and the parameters used to estimate loss of biomass.

Based on the Intergovernmental Panel on Climate Change and the Organization for Economic Cooperation and Development(IPCC/OECD) methodology, we estimated GHG emissions from forest clearing. Our estimate indicates that deforestation accounts for about 44% of national CO2 emissions. Carbon emitted from disturbed forest soils is not included in this estimate due to a lack of reliable data. Biomass burning that occurs in conduction with changes in land use is also an important contributor to trace gas emissions. Biomass burning accounts for approximately 5% of methane (CH4), 26% of nitrous oxides (N2O), 6% of nitrogen oxides (NOx), and 34% of carbon monoxide (CO). Estimates of GHG emissions are summarized in Table IV.2.

Uncertainties regarding estimates of GHG emissions from forest clearing are mainly attributable to data uncertainties with respect to deforestation rates and biomass densities. On the other hand, forests that are capturing carbon as a result of past human disturbances have not been included in the net carbon flux estimate due to the difficulty in tracking abandoned forest lands that are regaining vegetation cover. These uncertainties are also important limitations to the assessment of forest mitigation options.

Index    Next

If you have any questions or comments please contact us at VEBHM7SL@IBMMAIL.COM.