Emissions Scenarios - IPCC

134 Scénario Driving Forces
Table 3-5: Global fossil and fissile energy reserves, resources, and occurrences (in ZJ (10'^^J)). Global and regional estimates
are discussed in detail in Rogner (1997) and Gregory and Rogner (1998).
Consumption
1860-1990 1990
Reserves
Identified
Conventional
Resources
Remaining to be
Discovered
Low High
Recoverable
with
Technological
Progress
Additional
Occurrences
Oil
Conventional
Unconventional
3.35 0.13 6.3
7.1
1.6 5.9
9 >15
Gas
Conventional
Unconventional
Hydrates
1.70 0.07 5.4
6.9
9.4 22.6
20
>10
>22
>800
Coal 5.20 0.09 22.9 80 >150
Total 10.25 0.29 48.6 >11.0 >28.5 >109 >987
Nuclear 0.21 0.02 2.0 >11 > 1,000
geologic uncertainty, are not recoverable with current or
foreseeable technology, or are economically unwaiTanted at
present).
The assessment is summarized in Table 3-5. This account of
fossil resources needs to be put in context with the long-run
demand for these fuels and their relative production
economics. It is the specific demand for these fuels that
"converts" resources into reserves (Odell, 1997, 1998, 1999).
Obviously, this is a dynamic process that, in addition to future
demand trajectories, depends on advances in taiowledge and
technological progress. The discussion of oil reserves below
applies to all hydrocarbon and nuclear resources.
In terms of exploration, the oil industry is relatively mature and
the quantity of additional reserves that remain to be discovered
is unclear . One group argues that few new oil fields are being
discovered, despite the surge in drilling activity from 1978 to
1986, and that most of the increases in reserves results from
revisions of underestimated existing reserves (Ivanhoe and
Leckie, 1993; Laherrere, 1994; Campbell, 1997; Hatfield,
1997). Laherrere (1994) puts ultimately recoverable oil
resources at about 10 ZJ (1800 billion baiTcls), including
production to date. Adelman and Lynch (1997), while
accepting some aspects in the propositions behind the
pessimistic view of reserves, point to previous pessimistic
estimates that have been wrong. They argue that "there are
huge amounts of hydrocarbons in the earth's crust" and that
"estimates of declining reserves and production are incurably
wrong because they treat as a quantity what is really a dynamic
process driven by growing knowledge." Smith and Robinson
(1997) note improvements in technology, such as 3D seismic
surveys and extended reach (e.g. horizontal) drilling, that have
improved recovery rates from existing reservoirs and made
profitable the development of fields previously regarded as
uneconomic. Both of these increase reserves and lower costs.
The various arguments and assessments are reviewed in greater
detail in Gregory and Rogner (1998). To include all these views
and to reflect uncertainty, future reserves availability cannot be
represented by single numbers. Instead, a range of values that
reflect the optimistic and pessimistic assumptions on extent
and success rates of exploration activities, as well as the future
evolution of prices and technology, needs to be considered for
a scenario approach. To this end, the estimates of Masters et al.
(1994) reflect the current state of knowledge as to the
uncertainties in future potentials for conventional oil resources.
These estimates assess conventional oil reserves at slighdy
above 6 ZJ, and a corresponding range of additionally
recoverable resources between 1.6 and 5.9 ZJ. The figures
include estimates of oil that is yet to be discovered.
In addition to conventional oil reserves and resources, oil
shales, natural bitumen, and heavy crude oil, together called
unconventional oil resources, have previously been defined as
occurrences that cannot be tapped by conventional production
methods for technical or economic reasons, or both (Rogner,
1996, 1997). In part these resources represent some of the huge
amounts of hydrocarbons in the earth's cmst that Adelman and
Lynch (1997) refer to. Technologies to extract some of these
resources competitively at current market conditions are now
developed and production has started in countries such as
Canada and Venezuela. Masters et al. (1987) put total
recoverable resources of heavy and extra heavy crude oil at 3
ZJ, recoverable resources of bitumen at 2 ZJ, and ultimate
resources of shale oil in place at 79 ZJ (they do not estimate
the proportion of shale oil that might be recovered and hence