Emissions Scenarios - IPCC

128 Scenario Driving Forces
Such development is hard to measure in material terms.
Many writers refer to "dematerialization" and the
emergence of the "knowledge-based" economy.
• The start of a new "Kondratiev wave" may be
underway, to be revealed in the early 2P' century in a
surge of economic growth, with the massive
development of high-technology industries leading to
new products of increasing value and renewed
opportunities for fast developmental catch-up.
As a result, scenarios can span from low dematerialization to
high dematerialization futures associated with a wide range of
income levels. In the former, the shift toward more value-added
products in industry would be compensated by rising labor
productivity and hence lower product costs. Economic
production remains material oriented. It may be a world with
huge underground cities, air-conditioned tourist resort areas
with indoor beaches, a significant fraction of people in lowdensity
regions may fly their own aiфlanes, and robots may do
housework in most homes. In the latter, much of the money
flow would be associated with exchange of information and
services. Industrial value added would be, to a large extent,
generated from R&D and know-how, and less from increasing
productivity in traditional industries. Educational, childcare,
and medical services would make up a large part of personal
expenditures. Already, all kinds of artistic and handicraft work
have become part of the formal monetary economy, partly
because of the booming world tourist industry. Much
"economic growth" may revolve around the (re)distribution of
scarce, positional goods such as space and valuable artworks.
Therefore, the task of future scenario development entails more
than just the adoption of altemative quantitative assumptions.
The overall context within which altemative assumptions on
productivity growth or energy and materials intensity take
place needs to be made explicit. This is simply because many
key influencing factors (e.g., institutions) cannot be assessed
quantitatively, or the relationship between factors is known
only qualitatively. The development of altemative qualitative
scenario "storylines" (see Chapter 4) is therefore an important
advance over previous IPCC scenario methodologies.
3.4. Energy and Technology
3.4.1. Introduction
In this section, energy end-uses, resources, and technologies
are reviewed. Their future evolution is of critical importance to
future emissions levels. First, major pattems of energy end-use
and emissions by sector are considered, followed by a
discussion of energy resources; then energy supply
technologies that might become of greater importance in the
future are reviewed briefly before the current understanding
and modeling of technological change are discussed.
3.4.2. Energy Use and Emissions by Major Sectors
3.4.2.1. Overview
Sectoral energy use and GHG emissions changes are often
discussed in terms of trends in the major end-use sectors (e.g.,
Sathaye et al., 1989; lEA, 1997c; Schipper et al, 1997a; Price
et al, 1998). Trends reveal striking differences between sectors
and regions of the world. The key sectors of the economy that
use energy are industry (including agriculture), commercial,
residential, and institutional buildings, and transportation. Key
drivers of energy use and carbon emissions include activity
drivers (total population growth, urbanization, building, and
vehicle stock, commodity production), economic drivers (total
GDP, income, and price elasticities), energy intensity trends
(energy intensity of energy-using equipment, appliances,
vehicles), and carbon intensity trends. These factors are in tum
driven by changes in consumer preferences, energy and
technology costs, settlement and infrastructure patterns,
technical progress, and overall economic conditions.
Table 3-4 shows that global primary energy use grew from
191 EJ in I97I to 307 EJ in 1990 at an average annual growth
rate of 2.5% per year. This growth tapered off in all sectors
after 1990, and total global primary energy increased to only
319 EJ by 1995, mainly because of the large declines
experienced in the REF region (see Chapter 1 for definition of
SRES world regions) as a result of the political and economic
restracturing of the countries within it. Table 3-4 shows that
the industrial sector clearly dominates total primary energy
use, followed by the buildings sector (commercial,
residential, and institutional buildings combined), transport
sector, and agriculture sector.
Energy intensity is the amount of energy used to perform a
particular service, such as to produce a ton of steel, power a
refrigerator, or propel a vehicle. Technical progress generally
leads to improved energy efficiency in technologies such as
lights, vehicles, refrigerators, and manufacturing processes.
Many studies show that considerable energy efficiency
improvement can be realized (technically and economically) in
the short term (10-15 years) with available technologies
(Szargut and Morris, 1987; Ayres, 1989; Jochem, 1989; Lovins
and Lovins, 1991; Nakicenovic et al, 1993; WEC, 1995b;
Watson etal., 1996; Worrell etal., 1997).
In 1990, industry accounted for two-fifths of global primary
energy use, residential and commercial buildings for a slightly
smaller amount, and transportation for one-fifth of the total.
These shares vary according to economic structures in each
region (see below). Carbon emissions that result from energy
use depend on the carbon intensity of the energy source.
Changes in carbon intensity mainly result from fuel
substitution, but can also arise from changes in technology or
process. The largest shifts in carbon intensity over the long
term are associated with changes in the energy sources used for
power generation since 1850 (Nakicenovic and Grübler, 1996).
Smaller but still significant shifts resulted from fuel switching