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This Fact Sheet details the land-use implications of an expanding role for biofuel.
Use and Potential
Industrial-scale ethanol production exists in Brazil (from sugar cane) and in
the United States from corn. There is little fuelwood plantation project experience
from the AIJ phase (see Table 5-1). No significant
electric power supply based on plantation biofuel exists.
This practice's potential depends on success in enlisting and retaining local support for biofuel production on land from which communities have drawn their livelihood in other ways. Short-rotation forestry, corn, sugar cane, herbaceous plants, and grasses have been proposed, but the focus here is forestry.
The biofuel scenarios captured here project a rise in use from around 60 EJ (~10 EJ from waste) in 2020 to 300 EJ (~50 EJ from waste) in 2100, with land-use implications that depend on plantation productivity (see Section 4.5.3). Biofuel usage would rise from 10 oven dry tons of wood (~5 t C) (~200 GJ) ha-1 yr-1 to 25 oven dry tons of wood (~12.5 t C) (~500 GJ) ha-1 yr-1 over a century, leading to land usage that would rise from 250 Mha in 2020 to 500Mha in 2100. If these changes are realized, the potential fossil fuel offset in ~2040 would be as tabulated below.
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Areab
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Percent Usedc
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Avg. C-Capture Ranged
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Annual Capturee
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| Biofuel productiona |
6.2 Gha
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10% 7 t C ha-1 yr-1
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<2.5-20 t C ha-1 yr-1
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4.4 Gt C yr-1
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a Community-scaled production for small-scale gas turbine electricity generation and conversion to transport fuels (e.g., liquid-phase Fischer Tropsch processing) (5 percent) combined with agroforestry meeting local needs. b Cropland, grazing land, degraded land plus forest area vulnerable to predicted climate change. Of this area, 5 percent is in concentrated (a few km in size) biofuel plantations; an additional 10 percent is in 50-percent cover agroforestry, located in settlements in the locality of the plantations. In countries with developed energy supply systems and urbanized populations, less agroforestry is envisioned, with biomass initially accumulated in a long-rotation "buffer stock" awaiting renewal of existing capital stock. c Global average predicted after several decades of technological progress and management experience. A moderately conservative figure is used because species selection and management practices are assumed to be driven by multi-purpose sustainable development criteria. d Low figure = current, for conventional forestry; high figure = current small-plot experience in good growing conditions. e Subject to carbon content of displaced fossil fuel, which depends on fuel mix in power generation and on refinery balances in alternative fossil fuel supply system. |
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Removal from Atmosphere
Biomass growth absorbs CO2 that is returned to the atmosphere when it is used
as biofuel, providing a renewable fuel system that can be based on sustainable
cultivation practices. Removals from atmospheric CO2 result from substitution
in the commercial energy system, leaving fossil fuel underground. With traditional
wood fuel, the removal results from leaving standing natural forests that would
otherwise be lost.
Scientific and Socioeconomic Uncertainties
Technological uncertainties arise in relation to the community-scale application
of existing and near-term future biofuel conversion processes. The area covered
by individual plantations, the transportation cost of supply, and the environmental
and socioeconomic impacts depend on the scale of application technology. Recent
advances in reduced-scale electricity generation and liquid fuel production
from gas feedstocks (e.g., gasified biofuel) suggest that community-scaled plantations
no greater than about 10-km diameter can support cost-effective production of
commercial energy products (Read, 1999).
Economic uncertainties, for export-led growth based on the production of liquid biofuels, relate to future oil price trends, future credits for CO2 mitigation, and possible support for diversifying the liquid fuel resource base, reducing strategic dependence on dwindling low-cost oil supplies.
Sociocultural uncertainties arise with regard to sustaining commitment to biofuel-based employment and wealth-creating projects that are designed to match the cultural traditions and micro-economic interests of the communities concerned. This sustained commitment requires major capacity-building to enable sustainable technology transfer through country-driven projects that reflect the needs of local communities and host country priorities. This capacity-building entails a career structure for "Project Champions" qualifying at a rate of ~3000 p.a. in ~200 institutions in developing countries (Haque et al., 1999).
Time Scale
Even if the incentives provided by carbon credits and the potential energy productivity
of suitable land are sufficient to make reversal of deforestation trend driven
by economic pressures of the past few decades possible, this reversal cannot
be a short-term process. Rates of policy-driven land-use change that have been
modeled are broadly in line with that proposed in the Nordwijk Ministerial Declaration
of 1989.
Monitoring, Verifiability, and Transparency
Where products are commercially traded, market statistics and biofuel conversion
technology data provide an accurate basis for carbon absorption measurements,
as with fossil fuel emissions. Where products are used traditionally, "best
practice" project monitoring procedures and benchmark default estimates would
be needed.
Permanence
Where emissions savings come through retention of existing stocks of carbon
underground and in natural forest, permanence is no different from emissions
reduction and forest preservation measures, respectively. With absorption in
standing plantation timber, permanence depends on perpetuating community involvement
and the incentives that underpin project initiation. For environmental effectiveness,
insurance against natural hazards must take the form of additional planting
on lands in diverse locations.
Associated Impacts
Community-scaled plantations can transform lifestyles and fund investments in
sustainable food systems (e.g., based on agroforestry concepts) in the community.
Negative socioeconomic and environmental impacts are avoidable through good
project design. Rural electricity and fuelwood used in modern appliances provide
rural employment and reduced health risks from smoke inhalation. Environmental
benefits include cleaner air with sulfur-free liquid fuels; reduced soil degradation,
water runoff, and downstream siltation; capture of polluting agricultural runoff;
and utilization of wastes for plantation fertilization, avoiding landfill (Woods
and Hall, 1994). Famine is caused by poverty, not land shortage (Sen, 1981),
so carbon credit funding could help raise rural living standards and agricultural
productivity.
Relationship to IPCC Guidelines
The treatment of biofuels in the IPCC Guidelines is discussed in Chapter
6.
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