2013年以降の枠組としてのセクター別アプローチの評価と展望に関する研究

摘要

セクター別アプローチは，2013年以降における気候変動対応策の枠組候補の一つであり．産業などの 部門ごとに温室効果ガス排出原単位などの目標値を設定して改善を進める制度として注目されている。本論文 では，まず，専門家の主観的予測の整合性を高める手法であるクロスインパクト法を用い，12名のエクスパー トジャッジメントに基づいて採用される枠組の予測を行った。これにより．実現確率の高いいくつかの枠組候 補を抽出した。次に，専門家の主観的評価の整合性を高める階層化意思決走法を用い．3名のエクスパートジ ャッジメントに基づいて抽出された枠組候補の評価を行った。本論文の分析より．地球環境保全効果．経済影 響，制度設計上の問題，衡平性，外交上のイニシアティブなどの要因を総合的に評価した結果として，セクタ ー別アプローチの有効性が明らかとなった。%Since the fourth assessment report of IPCC was published in 2007, the worldwide concern on climate change has been growing unprecedentedly. While the first commitment period of Kyoto Protocol already started from 2008, international negotiation has begun on a framework in the next period. Under these circumstances, sector-based approaches are attracting attention, since it is not only promising to economically reduce greenhouse gas emissions, but also expected to be accepted by developing countries, In sector-based approaches, each nation set numerical targets as greenhouse gas intensities in individual sectors including industry, residence or transportation, so that it commits to reduce these intensities to realize the targets. In this paper, we first applied the cross-impact method to take experts' judgments consistently in order to project a framework after 2012. The computed results identified the several frameworks with high probabilities. Then we applied analytic hierarchy process to take experts' judgments consistently in order to evaluate the identified frameworks as candidates after 2012. In the evaluation using analytic hierarchy process, we took 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. We concluded that sector-based approaches are effective especially for developing countries.