Emissions Scenarios - IPCC

An Overview of Scenarios 213
Box 4-8: Technological Change in the AIM-based Quantifications for the Al Scenario Family
The Al storyline describes a world with rapid economic development. High economic growth results in pressures on resource
availability, counterbalanced by technological progress, which is assumed to be highest among the four scenario families. In the
AIM quantifications of the Al storyline, rates of technological change are high both with respect to "supply push" factors (most
notably RD&D) as well as with respect to "demand pull" factors (most notably high capital tumover rates). Since large resource
availability and high incomes stimulate demand growth, technological change in energy supply receives a higher emphasis
compared to changes in energy end-use technologies. Common technology assumptions in the Al scenarios can be summarized
as follows.
The supply of oil, gas, and biomass in the Al scenario family is assumed to be very high and results from high rates of
technological progress for fossil fuel and biomass exploitation technologies. Unconventional oil and gas, such as deep-sea
methane hydrates, oil shale, etc., become available at relatively low cost. Also, large amounts of biomass are utilized through
well-developed biomass farm plantations and harvest technologies, and biomass utilization technologies, such as biomass power
generation and biofuel conversion technologies, become available at low costs through RD&D and other mechanisms of
technology improvements (leammg by doing and leaming by using). High levels in the use of other renewable energy are
reached when technologies for solar photovohaics and thermal utilization, wind farms, geothermal energy utilization, and ocean
energy are introduced at low cost. Energy end-use technologies are assumed to progress at medium rates compared with the fast
rates of technological change in energy supply technologies.
The AlB marker and AIT scenarios assume drastic reductions in cost for solar, wind, and other renewable energies. AlC
assumes lower coal costs and emphasizes coal exploitation technology progress and the introduction of advanced coal-fired
power generation technology, such as integrated gasification combined cycle (IGCC). AIG assumes lower oil and gas costs than
other Al scenarios. The cost of nuclear power is assumed to be the lowest in AIG and AIT, and highest in AlC. The different
cost assumptions that drive and result from technological change in the Al scenario family are summarized in Table 4-12.
Table 4-12: Technology costs (1990US$IGJ afid 1990USCentslkWh} in AIM-based Al scenarios.
Scenarios 2020 2050 2100
Coal (1990US$/GJ) AlB 2.6 3.2 3.1
AlC 1.5 1.5 1.1
AIG 3.5 3.8 3.7
AIT 2.6 2.8 2.8
Natural Gas, ConventionalAlB 2.0 1.9 1.4
& Unconventional (1990US$/GJ) AlC 3.5 5.0 4.6
AIG 1.8 1.6 1.6
AIT 1.5 1.5 1.4
Grade OU, Conventional AlB 7.3 10.1 14.9
& Unconventional (í990m$/GJ) AlC 9.4 13.1 14.0
AIG 7.3 8.2 8.4
AIT 7.9 8.4 15.7
Nuclear (1990UScent/kWh) Al 5.4 3.9 2.3
AlC 5.7 4.4 2.8
AIG 5.9 4.7 3.1
AIT 5.6 4.1 2.5
Solar, wind, geothermal AlB 12.2 5.9 2.0
electricity (1990UScent/kWh) AlC 13.1 6.9 3.3
AIG 15.2 9.3 5.2
AIT 12.4 6.2 2.7
As mentioned above, improvements in energy efficiency on the demand side are assumed to be comparatively lower in the Al
scenario family, except for the AIT scenario, because the low energy prices give very little incentive to improve end-use energy
efficiencies. Efficient technologies are not fully introduced into the end-use side, dematerialization processes in the industiial
(Box 4.8 continues)