排放交易機制是以經濟誘因做為設計基礎的政策工具，無論在學理上或是實證上皆被證實具備成本有效性，亦即，能夠以相對較低的成本來達成溫室氣體減量的目標，因此成為晚近最常被規劃使用的氣候工具。而在國際排放交易機制上的發展，則以歐盟排放交易機制應用的規模最大、歷史也最攸久，因此累積了許多制度設計及執行經驗，該機制採用階段式試誤修正的推動執行策略、以及面對實務運作挑戰時的解決方式，是歐盟排放交易機制成為國際相關制度的參考典範。本文之目的，在於透過制度回顧方式，以檢視歐盟排放交易機制的發展現況，並針對該制度所面臨的挑戰及解決之道進行說明，最後則論及對台灣排放交易機制發展規劃之啟示。

Emission trading is one of the economic incentive mechanisms for emission pollution control policy. It is deemed as a cost-effectiveness scheme either in theory or in practice. That is, the targeted greenhouse gases emission reduction can be achieved with the lowest cost through this mechanism. As such, this mechanism is recently planned as a commonly used scheme for greenhouse gases emission reduction tool. Among these, European Emission Trading Scheme (EU ETS) has the largest scale, the longest history, and thus has cumulated the most scheme designs and implementation experiences. It turns out to be a reference and model for many nations or regions in designing such mechanism. The purpose of this paper is to review the scheme of EU ETS, its development, potential challenges in the future, and possible resolution. The implication for the development of ETS in Taiwan is also highlighted.