Emissions Scenarios - IPCC

An Overview of Scenarios 221
Table 4-14: Primary energy use (EJ)for the four SRES marker scenarios and all SRES scenarios in 1990, 2020, 2050, and
2100. The range for 1990 illustrates the differences in base-year calibration across the models and uncertainties that stem
from the inclusion or exclusion of non-commercial energy use, which is particularly important for developing countries.
Primary Energy (EJ) by World and Regions
2050 2100
Region 1990 Al A2 Bl B2 Al A2 Bl B2
OECD90 151-182 267 266 166 236 397 418 126 274
(184-315) (207-300) (134-233) (189-236) (181-607) (267-496) (126-274) (197-274)
REF 69-95 103 93 64 97 139 155 39 125
(83-267) (57-116) (50-79) (53-117) (70-290) (61-457) (25-80) (40-328)
IND 227-252 370 359 230 334 536 573 164 399
(303-532) (264-406) (203-303) (255-339) (275-896) (385-847) (164-345) (237-593)
ASIA 49-79 440 335 272 319 838 581 154 521
(293-789) (249-449) (204-537) (284-411) (308-965) (477-753) (154-434) (309-562)
ALM 35-49 538 278 312 217 852 563 196 437
(235-634) (166-354) (176-312) (137-254) (391-1109) (437-662) (196-446) (300-538)
DEV 84-123 977 612 583 536 1639 1144 350 959
(606-1278) (415-740) (406-837) (421-660) (700-2074) (914-1375) (350-880) (609-1096)
WORLD 326-368 1347 971 813 869 2226 1717 514 1357
(913-1611) (679-1059) (642-1090) (679-966) (1002-2737) (1304-2040) (515-1157) (846-1625)
direct equivalent method for all non-thermal uses of
renewables and nuclear. The primary energy equivalence of
these energy forms is accounted for at the level of secondary
energy, that is, the first usable energy form or "currency"
available to the energy system. For instance, the primary
energy equivalence of electricity generated from solar photovoltaics
or nuclear power plants is set equal to their respective
gross electricity output, not to the heat equivalent of radiation
energy from fissile reaction, the solar radiance that falls onto a
photo-voltaic panel and is converted into electricity with
efficiencies that range from 10% to 15%, or the heat that would
have to be generated by buming fossil fuels to produce the
same amount of electricity as generated in a photo-voltaic cell
or a nuclear reactor (as used in the so-called "substitution"
accounting method). This common^^ SRES accounting
convention must be bome in mind when comparing the
primary energy-use figures of this report with those of other
studies, which invariably use different accounting methods
depending on the organization that produces the scenario. An
illustration of the sensitivity of different accounting methods
on estimates of primary energy use in long-term energy
scenarios is given in Nakicenovic et al. (1998). (See also the
discussion in Chapter 2, in which scenario comparisons are
based on index numbers rather than absolute figures to account
for these definitional differences.)
Adopting a common accounting convention avoids
misrepresentation of the contribution of renewable and other new
energy forms, which can be both under- or over-represented by
inconsistent accounting conventions, as continues to be the case in
energy statistics and scenario studies.
Table 4-14 gives an overview of primary energy use in the four
SRES marker scenarios and the range of all SRES scenarios.
Figure 4-11 illustrates both the historical change of world
primary energy structure over time and future changes as given
in the SRES scenarios. Each comer of the triangle coiTesponds
to a hypothetical situation in which all primary energy is
supplied by a single source - oil and gas at the top, coal at the
left, and non-fossil sources, renewables (including wood), and
nuclear at the right. The historical change reflects major
technology shifts from the traditional use of renewable energy
flows to the coal and steam age of the 19* century, and
subsequently to the dominance of oil and internal combustion
engines in the 20* century. In around 1850 (lower right of
Figure 4-11), only about 20% of world primary energy was
provided by coal; the other 80% was provided by traditional
renewable energies (biomass, hydropower, and animal energy).
With the rise of industrialization, coal substituted for
traditional renewable energy forms, and by 1910 (lower left of
Figure 4-11) around three-quarters of world primary energy
use relied on coal. The second major transition was the
replacement of coal by oil and later by gas. By the early 1970s
(see 1970 point labeled on Figure 4-11), 56% of global primary
energy use was based on oil and gas. From the early 1970s to
1990, the global primary energy structure has changed little,
although efforts to substitute for oil imports have led to an
increase in the absolute amount of coal used and to the
introduction of non-fossil altematives in the OECD countries
(e.g., nuclear energy in France). Rapid growths in energy
demand and coal use, particularly in Asia, have outweighed
structural changes in the OECD countries.