Evaluation of post-Kyoto frameworks focusing on sector-based approaches and national numerical targets.
Matsuhashi, Ryuji ; Mori, Hiromasa ; Misumi, Kohei 等
1. Introduction
Since the fourth assessment report of IPCC was published in 2007,
worldwide concern on global warming has been escalating unprecedentedly.
Response strategies to climate change were raised as the most important
issue also in the Heiligendamm summit in June, 2007. Since the first
commitment period started this year, they are making the sincere effort
to comply with the numerical target in Annex-one countries ratifying
Kyoto Protocol.
On the other hand, international negotiation has also started from
COP13 in 2007 on the framework to mitigate climate change after 2013,
what we call post-Kyoto framework. Japanese government advocated
sector-based approaches as post-Kyoto candidates. Taking these
situations into consideration, this paper aims at analyzing the
post-Kyoto framework, centered on sector-based approaches.
2. Examination of post-Kyoto frameworks
As long as Kyoto Protocol is concerned, United States of America
already resigned from the protocol. Developing countries do not have
national numerical targets in the protocol, even if they are ratifying
it. Furthermore, Kyoto mechanisms are presently not functioning ideally
due to complicated certification procedures of CDM. Therefore
involvement of developing countries through Kyoto mechanisms is not very
efficient for the moment. It is significant to establish a post-Kyoto
framework enabling meaningful participation of the United States and
developing countries.
Various proposals are already made on the post-Kyoto frameworks
including sector-based approaches. In general, sector-based approaches
set targets on energy efficiency or greenhouse gas emission intensity on
individual sectors including industry, residence or transportation, in
which they improve to realize the targets (Schmidt et al., 2006).
In Davos meeting in January, 2008, Japanese Prime Minister, Mr.
Fukuda advocated a sector-based bottom up approach, in which each nation
is able to evaluate rational numerical target by summing up greenhouse
gas emission in each sector. The greenhouse gas emission in each sector
is determined by setting a target on its greenhouse gas emission
intensity. On the other hand, Japanese government also advocated another
type of a framework, cooperative sector-based approach. This approach
adopts some key sectors, in which they improve greenhouse gas emission
intensities worldwide by transferring efficient technologies. In this
sense, the cooperative sector-based approach is closely related with
mechanisms for technology transfer such as CDM. Thus sector-based
approaches have wide institutional variations. The above classification
depends on whether a sector-based approach is for national or
international framework. We have also to take account of the
classification based on whether it is for all sectors or part of
sectors, and whether it is with or without technology transfer.
Taking these factors into consideration, we propose the following
classification for sector-based approaches including national numerical
targets as in Kyoto Protocol.
(1) Complete sector-based approach
In this institution, all domestic GHG emissions are classified into
individual sectors. For instance, they are divided into GHG emission in
iron and steel, cement, pulp and paper, etc. in industry. In the same
way, GHG emissions are classified into each sector also in residence,
transportation and energy conversion. This approach sets targets on
energy efficiency or greenhouse gas emission intensity on individual
sectors, which they improve to realize.
(2) Complete sector-based approach with a mechanism for technology
transfer This institution is the same as the above mentioned complete
sector-based approach except for the following point. Namely, this
institution recognizes technology transfers without the present
complicated certification as CDM by setting simple benchmarks for GHG
intensities.
(3) Partial sector-based approach
So as to realize the above-mentioned complete sector-based
approach, we have to prepare data inventories on GHG emission
intensities of all sectors. However, it might be difficult to prepare
the reliable inventories in some sectors. Therefore they deal only with
energy intensive sectors with reliable data such as iron and steel,
cement and electric power generation in the partial sector-based
approach. Then this approach sets targets on energy efficiencies or
greenhouse gas emission intensities on the above key sectors to realize
the targets.
(4) Partial sector-based approach with a mechanism for technology
transfer This institution is the same as the above mentioned partial
sector-based approach except for the following point. Namely, this
institution recognizes technology transfers without the present
complicated certification as CDM by setting simple benchmarks for GHG
intensities for energy intensive industries separated from national
numerical targets. Namely, this corresponds to the cooperative
sector-based approach in Mr. Fukuda's proposal.
(5) Overall national numerical target
National numerical targets are also included in our analyses, which
are imposed to Annexone countries in Kyoto Protocol. As described above,
we could utilize the concept of sectorbased approaches even in the
national numerical targets, in which we sum up GHG emissions of
individual sectors to identify rational numerical targets. Namely, this
includes the bottom-up sector-based approach.
3. Projections on the post-Kyoto frameworks
It is useful to identify frameworks of high probability of
realization in future. Here we estimate likelihood of realizing each
framework. For this purpose, we propose a methodology combining
cross-impact method and Bayesian inference.
In the cross-impact method, we solve the quadratic programming
problem as shown in Equation (1) to acquire solution. (2) The Criterion
to be minimized is shown in Equation (1). Table 3 shows the seven basic
events, of which combination likelihoods are estimated by the
cross-impact method. Seven basic events generate 2 (7) = 128 kinds of
scenarios, since each event has two consequences, 1 or 0.
[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (1)
In the cross-impact model, [E.sub.k] means scenario k, which is
determined by combination of seven kinds of basic events. On the other
hand, [e.sub.i] is a basic event i. For each scenario, [[pi].sub.k]
implies a likelihood of the scenario, [E.sub.k], where P(i) corresponds
to a likelihood of ei. P(i|j) means conditional likelihood. Regarding
P(i) and P(ij), [[theta].sub.ik] is a pseudo variable for scenario k to
be 1 with generation of [e.sub.i], and to be 0 without generation of
[e.sub.i], where [t.sub.ijk] is a pseudo variable for scenario k to be 1
with generation of both [e.sub.i] and [e.sub.j], and to be 0 in the
other cases.
Table 1 shows the seven basic events, of which combination
likelihoods are estimated by the cross-impact method. Seven basic events
generate 2 = 128 kinds of scenarios, since each event has two
consequences, 1 or 0.
It is difficult to directly estimate likelihoods of 128 scenarios
even for experts. In the cross-impact method, we have only to estimate
probabilities for seven single events, and to estimate conditional
probabilities for combinations of every two events by expert judgments.
Then we can estimate likelihoods of the hundred and twenty eight
scenarios to minimize the probabilistic contradictions denoted in
Equation (1).
As actual procedures, we sent questionnaires to the twelve experts
and obtained the expert judgments. We solved the above quadratic
programming for these estimates. Then we averaged the calculated
probabilities of 128 scenarios among the thirteen expert judgments.
After the cross-impact evaluation, the world experienced a few
significant events on postKyoto negotiation, such as Davos meeting and
Toya-lake summit in Table 2. Therefore we adopted Bayesian inference to
consider information from these events. According to Bayes'
theorem, we can improve quality of our projection empirically by the
following equation. We are able to utilize the equation (2) as a
recursion formula. Namely, posterior probability,
P([A.sub.i]'/[event.sub.k]) after an [event.sub.k] is able to be
used as prior probability before a next [event.sub.k+1].
P([A.sub.i]'/[event.sub.k]) =
P([A.sub.i])P([event.sub.k]/[A.sub.i])/[summation over (j)]
P([A.sub.j])P([event.sub.k]/[A.sub.j]) (2)
P([A.sub.i]'/[event.sub.k]): Conditional probability of
[A.sub.i] in generation of an [event.sub.k]
P([A.sub.i]): Probability of [A.sub.i] before an [event.sub.k]
P([event.sub.k]/[A.sub.i]): Conditional probability of an
[event.sub.k] in generation of [A.sub.i]
Actual procedures are as follows to combine the cross-impact method
and Bayesian inference for quantifying the probability of post-Kyoto
scenarios.
(1) We sent the questionnaires to the twelve experts after the
above [event.sub.1].
(2) Based on the responses, we applied the cross-impact method to
quantify probabilities of the hundred and twenty eight post-Kyoto
scenarios. Namely, these probabilities are estimated before the
[event.sub.2], [event.sub.3], and [event.sub.4].
(3) We applied the Bayesian inference to include influences of
the[event.sub.2], [event.sub.3], and [event.sub.4]. We revise
P[(.sub.Ai]) (i=1,2,... 7) of the responses of all experts, using the
equation (2).
(4) Based on the revised P([A.sub.i]), we applied the cross-impact
method once more to quantify probabilities of hundred and twenty eight
post-Kyoto scenarios. Namely, these probabilities are estimated taking
the influence of the [event.sub.2], [event.sub.3], and [event.sub.4]
into consideration.
Figure 1 shows likelihoods of the post-Kyoto frameworks estimated
by the cross-impact method in the above procedure (4). Namely, these
probabilities are estimated taking the influence of the [event.sub.2],
[event.sub.3], and [event.sub.4] into consideration. In particular, it
shows six in the hundred and twenty eight scenarios with high
probabilities. In the figure, the points are average values of
cross-impact estimates based on the twelve expert judgments, while the
bars around the points express two times of standard deviations in the
estimates.
The national numerical targets for industrialized countries are
adopted in five out of the six scenarios. Among the five scenarios,
Scenario 1 has the highest average probability more than twenty
percentages, in which developing countries do not have any obligations
but flexibility measures. In this sense, Scenario 1 is similar to the
framework in Kyoto-protocol. The other scenarios, Scenario 2 and 3 have
relatively high probabilities between ten and twenty percentages, in
which developing countries adopt the partial sector-based approach and
the complete sector-based approach with flexibility measures,
respectively. The other two scenarios are Scenario 4 and 5. In Scenario
4, developing countries adopt partial sector-based approach, while they
do not have any obligations in Scenario 5.
In four out of the six scenarios, the complete or the partial
sector-based approaches are adopted in industrialized or in developing
countries. Even if the national numerical targets are imposed as the
post-Kyoto framework, the concept of the bottom-up sector-based
approaches can be adopted to set rational targets. Thus the likelihood
of sector-based approaches is not low from present circumstances.
[FIGURE 1 OMITTED]
Figure 2 compares the probabilities of the six most probable
scenarios before and after the events. In particular, the probabilities
in scenario 2, 3 and 4 drastically increased by influence of the
[event.sub.2], [event.sub.3], and [event.sub.4]. For instance, they
concluded that cooperative sector-based approach is effective to reduce
worldwide greenhouse gas emissions through technology diffusion. These
incidents increased the probabilities of scenario 2, 3 and 4, in which
sector-based approaches are adopted in developing countries.
[FIGURE 2 OMITTED]
Figure 3 shows integrated probabilities of post-Kyoto frameworks in
the hundred and twenty eight scenarios taking the events into
consideration. For instance, we sum up probabilities of scenarios, in
which national numerical targets are adopted in developed countries, as
far as the left bar is concerned. In developed countries, the
probability of national numerical target is high around eighty
percentage points. In Toya-lake summit, they concluded that the
bottom-up sector-based approach is useful to set rational numerical
targets for developed countries. These incidents increased the
probabilities of national numerical targets in developed countries. On
the other hand, probabilities of sector-based approaches became high in
developing countries.
[FIGURE 3 OMITTED]
4. Comparative analyses on the post-Kyoto frameworks
In this article, we made a comparative analysis of the above six
frameworks by Analytic Hierarchy Process based on the structure shown in
figure 4. Regarding criteria on the post-Kyoto frameworks, we need to
include economic impacts, participation of developing countries and
making consensus and so on as well as mitigating climate change.
[FIGURE 4 OMITTED]
Weights of each criterion were estimated by Eigenvectors of
pair-wise comparison matrices, as shown in table 3.
[FIGURE 5 OMITTED]
Estimated results of the six scenarios identified in the last
chapter are shown in the figure 5. As a result of AHP, Scenario 5, in
which only developed countries adopt national numerical targets, has the
lowest score. This is mainly because certainty and flexibility in
reducing greenhouse gas emissions is low. Scenario 1, in which
developing countries accept only flexibility measures, has also a
relatively low score less than 0.6, mainly because certain reduction of
greenhouse gas is not ensured in developing countries. Thus it is
significant to effectively reduce greenhouse gas emissions in developing
countries.
The score of Scenario 2 is higher than Scenario 3, although
developing countries adopt the complete or the partial sector-based
approaches in both scenarios. This is mainly because reliability on data
acquisition is lower in the complete than in the partial sector-based
approach.
Scenario 2, in which developed countries adopt national numerical
targets and developing countries adopt partial sector-based approach
with flexibility measures, has the highest score. The reason is as
follows. At first, acceptability of partial sector-based approach is
higher than national numerical targets for developing countries. Second,
certainty of reducing greenhouse gases is high, since developed
countries adopt national numerical targets. The likelihood of
Scenario 2 by our methodology was also shown to be considerably
high in the last chapter. In short, this framework deserves exploration
both from likelihood and from evaluation.
5. Conclusion
In this paper, we first proposed the methodology combining the
cross-impact method and Bayesian inference to project what type of
institution will be adopted as post-Kyoto frameworks. Namely, we
utilized Bayesian inference to introduce influences of significant
international events into expert judgments, in which probabilistic
consistency was maximized by the cross-impact method. Computed results
by this methodology identified the several frameworks as post-Kyoto
candidates with high probabilities. In the four among six scenarios, the
complete or the partial sector-based approaches are adopted in
industrialized or developing countries.
Then we evaluated the candidates for post-Kyoto frameworks. For
this purpose, analytic hierarchy process is applied, taking account of
reduction of greenhouse gases, economic impact, possibility of making
consensus, and initiative in global negotiation. The evaluated result
indicated that the framework has the highest score, in which
industrialized and developing countries adopt national numerical target
and partial sector-based approaches, respectively. This framework was
concluded to deserve exploration both from the projection and the
evaluation in this paper.
Even if the national numerical targets are imposed as the
post-Kyoto framework, we can apply the sector-based bottom-up approach
to set rational numerical targets. Furthermore, developing countries
without any numerical targets in Kyoto Protocol would be able to play a
significant role in the post-Kyoto framework by adopting sector-based
approaches. Namely, sector-based approaches could bring about more
reduction of greenhouse gases in developing countries than in the first
commitment period. We concluded that sector-based approaches with wide
institutional variations are effective for both industrialized and
developing countries.
References
Jake Schmidt et. al. (2006). Sector-based Approach to the Post-2012
Climate Change Policy Architecture, Center For Clean Air Policy.
Hisashi Ishitani, Masumi Ishikawa (1992). Series of Mathematical
analysis in modern times 2, "Social systems engineering",
Asakura books.
Kohei Misumi, Ryuji Matsuhashi and Yoshikuni Yoshida (2007) A Study
on Negotiation Strategy of Post-Kyoto Framework to mitigate climate
change, Journal of Environmental Informatics in Japan, Vol.21, pp
405-410.
Ryuji Matsuhashi, Institute of Environmental Studies, Graduate
School of Frontier Sciences, The University of Tokyo
Hiromasa Mori, Institute of Environmental Studies, Graduate School
of Frontier Sciences, The University of Tokyo
Kohei Misumi, Graduate School of Law, The University of Tokyo
Yoshikuni Yoshida, Institute of Environmental Studies, Graduate
School of Frontier Sciences, The University of Tokyo
Table 1. Seven basic events adopted in the cross-impact method.
[A.sub.1] National numerical targets will be imposed as the first
commitment period in industrialized countries.
[A.sub.2] National numerical targets will be imposed as the first
commitment period in developing countries.
[A.sub.3] GHG emissions from energy intensive industries will be
dissociated from national numerical targets and managed by
sector-based approach in industrialized countries.
[A.sub.4] GHG emissions from energy intensive industries will be
dissociated from national numerical targets and managed by
sector-based approach in developing countries.
[A.sub.5] Flexibility measures such as CDM in Kyoto Protocol will be
diffused worldwide.
[A.sub.6] GHG emissions from all sectors will be managed by sector-
based approach in industrialized countries.
[A.sub.7] GHG emissions from all sectors will be managed by sector-
based approach in developing countries.
Table 2. The events influencing the post-Kyoto negotiation.
[Event.sub.1] In COP13 meeting in 2007, Japanese government
advocated the cooperative sector-based approach, which
was included in the Bali Action Plan.
[Event.sub.2] In Davos meeting in January, 2008, Japanese Prime
Minister, Mr. Fukuda advocated the sector-based bottom
up approach, in which each nation is able to evaluate
rational numerical target by summing up greenhouse gas
emission in each sector.
[Event.sub.3] Chinese paramount leader, Hu Jintao visited Japan in
May, 2008 to meet Japanese prime minister, Fukuda.
After the meeting, he stated that sector-based
approaches are significant measures to reduce
worldwide greenhouse gas emissions.
[Event.sub.4] In Toya-lake summit, they concluded that bottom-up
sector-based approach is useful to set rational
numerical targets for developed countries. At the same
time, they also confirmed that cooperative sector-
based approach is also effective to reduce worldwide
greenhouse gas emissions through technology diffusion.
Table 3. Weights of criteria and sub-criteria in the post-Kyoto
frameworks
Criteria Sub-criteria Weights Weights of
of criteria sub-criteria
Reduction of GHGs Certainty 31.7% 15.8%
Flexibility 15.8%
Economic impact Short term 28.9% 18.3%
Long term 10.6%
Issues on designing Issues on making 18.3% 11.6%
frameworks consensus
Reliability on data 6.7%
Participation of 10.6% 5.3%
Equity developing countries
Responsibility on
cumulative emissions 5.3%
Initiatives in international society 10.6% 10.6%
