4.5. Biofuels and Forest Products
This section focuses on biofuels and forest products and their implications
for land use and carbon dynamics. Section 4.4.5
discusses the in situ stock of carbon in growing forest; this section deals
with carbon in forest products (Section 4.5.6) and the
tradeoff between biofuels and in situ sequestration, including environmental
and socioeconomic impacts (Sections 4.5.2, 4.5.3,
4.5.4 and 4.5.5). Fact Sheets
at the end of this chapter deal with tradeoffs (Fact Sheet
4.20), biofuel from plantations (Fact Sheet 4.21),
and biofuel from food and fiber production wastes such as sawdust (Fact
When biomass displaces fossil fuels, the mitigation is captured as a decrease
in fossil fuel use. The change in carbon stored in and on the land during biofuel
growth must be accounted for separately. Tradeoffs between carbon storage and
displacement of fossil fuels and energy-intensive materials have implications
for land use and forest management. Article 3.3 of the Kyoto Protocol clearly
distinguishes between biofuels and fossil fuels, establishing that biofuels
are part of the cycling of carbon in the biosphere. Distinguishing biofuels
from other fuels entails assessing options for managing carbon through the land-use
change and forestry sector and looking at effects in the energy sector.
Globally, biofuel contributes about 14 percent of primary energy supply. Most
biofuel use is traditional wood fuel in developing countries, but agricultural
and forest wastes provide significant industrial feedstocks for energy production
in developed economies (see Fact Sheets 4-21 and 4-22).
Modern biofuel technology can provide electricity, gases, and transportation
fuels and more efficiently support traditional uses of wood fuel, with environmental
and social benefits. These benefits include job creation, productive use of
surplus agricultural land, avoidance of health hazards from traditional wood
burning, reduced urban and agricultural wastes, and nutrient recycling.
Agroforestry systems can provide multiple benefits, including energy, to rural
communities, with synergies between sustainable development and GHG mitigation.
Large-scale biofuel production raises questions, however, involving land availability
and productivity (short- and long-term), species selection and mixtures, environmental
sustainability, social and economic feasibility, and ancillary effects. Issues
include fertilizer and pesticide requirements, nutrient cycling, energy balances,
biodiversity impacts, hydrology and erosion, conflicts with food production,
and the level of financial subsidies required.
Three broad questions arise if biofuels are to significantly reduce net CO2
- Is sufficient land available to meet demand for food, fiber, and energy?
- Do adverse environmental and social impacts negate the advantages of biofuels?
- Why aren't modern biofuels more widely used now?
Underlying these questions is the tradeoff between stocking carbon in standing
forest and producing a flow of woody biomass that displaces fossil fuels directly
as biofuel or by displacing energy-intensive building materials.
The key message of this section is that managing land use for maximum on-site
carbon storage may not always result in the most effective mitigation of GHG
emissions. Increased carbon storage in the biosphere yields benefits, but over
time greater mitigation is possible by managing the entire system-including
the production and use of biofuels and other products.
From a policy perspective, the potential for biofuel displacement of fossil
fuel is an order of magnitude greater than any other land-use change. It may
also impact atmospheric carbon levels earlier and at lower cost than other energy
sector measures. This consideration has significant precautionary potential
against the possibility that undesired climate effects may occur at lower levels
of atmospheric GHG than have been previously postulated (e.g., the threshold
for rapid, nonlinear climate change, which is currently unknown) (Houghton,