IPCC: CO2 Cuts Cost Little
MANY ALTERNATIVES FOR CO2
CUTS, SAYS IPCC PANEL
Substantial cuts in global emissions of carbon dioxide
(CO2), the leading greenhouse gas implicated in climate change,
can be achieved over the next 30 years through a variety of
technology and policy options at little or no increase in cost
over business as usual, according to Working Group II of the
Intergovernmental Panel on Climate Change (IPCC).
In its new "Summary for Policymakers," released in November
(see WIND ENERGY WEEKLY #676, December 11, 1995), the panel
examines several alternatives for world energy supply through the
year 2100. All options reviewed envision very large growth in
energy from "intermittent renewables" (wind and solar) over the
Global energy use is a major contributor to the increase of
greenhouse gases in the atmosphere. According to the report, 385
EJ [exajoules; one exajoule is equal to 45 million tons of coal
or 170 million barrels of oil] of energy were consumed worldwide
in 1990, resulting in the release of six billion tons of carbon
[22 billion tons of carbon dioxide] into the atmosphere. Added
the report, "Future energy demand is anticipated to continue to
grow, at least through the first half of the next century. The
IPCC . . . projects that without policy intervention, there could
be significant growth in emissions from the industrial,
transportation, and commercial/residential buildings sectors."
In 1992, the IPCC developed six energy scenarios based on
different supply assumptions. All but one (a case with very low
population and economic growth) showed substantial increases in
CO2 emissions, from 22 billion tons in 1990 to a range of 36
billion tons to 128 billion tons per year in 2100.
Working Group II, however, found that emissions could be
restrained well below all of the 1992 IPCC projections, even with
high future energy demand. It developed five new scenarios of a
Low CO2-Emitting Energy Supply System (LESS), which it said are
"'thought experiments' exploring possible global energy systems."
In the LESS scenarios, world population grows from 5.3
billion in 1990 to 10.5 billion by 2100. Economic growth, in
terms of gross domestic product (GDP), jumps to 25 times 1990
levels by 2100, with 13-fold increases in industrialized
countries and 70-fold increases in developing countries. Heavy
use is made of energy efficiency measures in all scenarios.
According to the working group, "[A]nalysis of these variants
leads to the following conclusions:
Added the report, " . . . [W]ithin the wide range of future
energy prices, one or more of the [scenarios] would plausibly be
capable of providing the demanded energy services at estimated
costs that are approximately the same as estimated future costs
for current conventional energy."
- "Deep reductions of CO2 emissions from energy supply systems
are technically possible within 50 to 100 years, using
- "Many combinations of the options identified in this
assessment could reduce global CO2 emissions from fossil
fuels from about [22 billion tons] to about [15 billion
tons] by 2050, and to about [seven billion tons] by 2100 . .
- "Higher energy efficiency is underscored for achieving deep
reductions in CO2 emissions, for increasing the flexibility
of supply side combinations, and for reducing overall energy
system costs. . ."
The report spoke in positive terms of renewable energy
sources, noting in part, "Solar, biomass, wind, hydro, and
geothermal technologies already are widely used. In 1990,
renewable sources of energy contributed about 20% of the world's
primary energy consumption, most of it fuelwood and hydropower.
"Technological advances offer new opportunities and
declining costs for energy from these sources. In the longer
term, renewable sources of energy could meet a major part of the
world's demand for energy. Power systems can easily accommodate
limited fractions of intermittent generation, and with the
addition of fast-responding backup and storage units, also higher
Each of the LESS scenarios sees substantial growth in
intermittent renewables. By the year 2025, in the nuclear-
intensive LESS forecast--the worst of the five for intermittent
renewables--wind and solar would deliver 34.8 EJ (about 3.2
trillion kWh annually, or more electric power than the U.S. uses
today), worldwide, and by the year 2100, 103.9 EJ (9.5 trillion
kWh). In the biomass-intensive, gas-intensive, and coal-
intensive scenarios, intermittent renewables are projected to
deliver 37.1 EJ (3.4 trillion kWh) annually by 2025 and 163.2 EJ
(15 trillion kWh) by 2100. And in the high-demand LESS scenario,
intermittents deliver 37.1 EJ in 2025 and 318.3 EJ (29 trillion
kWh) in 2100.
Continues the report, "The literature provides strong
support for the feasibility of achieving the performance and cost
characteristics assumed for energy technologies in the LESS
constructions, within the next two decades, though it is
impossible to be certain until the research and development is
complete and the technologies have been tested in the market.
"Moreover, these performance and cost characteristics cannot
be achieved without a strong and sustained investment in
research, development, and demonstration (RD&D). Many of the
technologies being developed would need initial support to enter
the market, and to reach sufficient volume to lower costs to
"Second Assessment Report, Summary for Policymakers:
Impacts, Adaptations and Mitigation Options" is available from
IPCC Working Group II Technical Support Unit, 300 D Street, SW,
Suite 840, Washington, DC 20024, USA, phone (202) 651-8260, fax
(202) 554-6858, e-mail firstname.lastname@example.org
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