巴黎協定對排放權交易制度之連結所可能帶來之影響：由下而上或由上而下的管制工具？

Implications of the Paris Agreement to Linking Emissions Trading Systems:Bottom-up or Top-down Approach?

國際氣候變遷管制體系於巴黎協定出現後，清楚呈現由下而上的管制趨勢，同時，於京都議定書生效後所興起的排放權交易制度，出於經濟效益與環境完整性的考量，開始進行各種形式的連結，所謂的連結指的是一國的核配量，可以直接或間接的為另一國的機制下之參與者用作滿足法定義務，而巴黎協定即將完成談判的兩年前，世界銀行與一些學者另提出有關連結的新倡議，相較於傳統之連結類型較偏向由下而上的模式，連結類型的新倡議於某程度內有朝向由上而下的趨勢，此與巴黎協定是否呈現相反的發展趨勢？此為本文欲回答之研究問題。本文先介紹連結的觀念與類型、以及連結的法律構面，隨後介紹連結類型的新倡議，並將之與傳統連結類型相比較，以觀察連結此一工具的發展趨勢，之後針對巴黎協定兩大由下而上的管制特色——國家自主貢獻以及第6條下的合作途徑——進行介紹，最後並據此分析巴黎協定對連結可能帶來的影響。本文的分析發現，目前連結的實例多半是發生於區域或地方層級間的排放權交易制度，此與巴黎協定本質上還是以國家為主體的狀況即有不同，亦即是此「下」非彼「下」，巴黎協定的合作途徑，對於排放權交易制度連結的發展是維持由下而上、擁抱由上而下、或兩者併行，並無法發揮決定性的影響力，但起碼在國家層級間的排放權交易制度連結上，巴黎協定之合作途徑最終談判出的操作規則或許可發揮一些影響力與助力。

Paris Agreement has been identified as embracing a bottom-up approach within the international climate change legal regime. Meanwhile, emissions trading systems at all level began to envisage, or even to implement linkage for economic and environmental reasons around mid-2000. Linking refers to the phenomenon where one country’s allowance can be used, directly or indirectly, by a participant in another country’s scheme for compliance purposes. Apart from the more traditional approach of linking, World Bank and a group of researchers, at around the time when the Paris Agreement was being negotiated and about to be concluded, have proposed new types of linking for the purpose of creating a global carbon market. In comparison to the more bottom-up traditional linking approaches, these new initiatives try to introduce a certain top-down institutional design. Does this mean that the regulatory trend introduced by the Paris Agreement is inapplicable in the practices of linking emissions trading systems? This is the central research question this article seeks to explore. This article will first introduce the concept of linking, as well as the legal elements of executing a linkage. New initiatives for linking will then be discussed for the purpose of identifying any observable trend in the regulatory approach. The article will proceeds to resent two elements of the Paris Agreement that clearly demonstrates its bottom-up regulatory approach: the nationally determined contributions and cooperative approach under Article 6. Based on these findings, the article will analyze the implication of the Paris Agreement to the policy tool of linking. The article finds that current practices of linking often takes place between emissions trading systems that operate at the regional or subnational level, instead of national level. On the other hand, Paris Agreement, as an international treaty, is still a country-driven process. Thus, the level of “bottom” actually refers to different concept in the practice of linking. As a result, the Paris Agreement might play a very limited role in encourage the regulatory development of linking, especially at the regional or subnational level. Nevertheless, the cooperative approach under Article 6 of the Paris Agreement might have more positive impact on linking emissions trading systems that operate at the national level, depending on the final rules regarding its operation.