由於能源短缺、溫室氣體排放、全球暖化及氣候變遷等潛在危機，不僅威脅全球的自然生態與環境，同時亦對經濟成長造成嚴重的衝擊。在各類溫室氣體中，又以二氧化碳比重最高（約占七成左右），使其成爲影響全球溫室效應最主要的氣體。節能減排近年來已蔚爲國際組織共同關注的問題，亦爲國內各界咸所重視的政策焦點，相關目標與政策的研擬無不成爲各國施政重點之一。惟適當且有效之政策工具的擬定，須詳實掌握各項政策工具對節能減排及經濟成長的影響。本文深入回顧相關文獻之理論與實證方法，據以建立適合臺灣的3E聯立模型，並進行實證分析，藉以推估多項政策工具（如環境稅、關稅，以及能源價格等）與經濟變數（如貿易條件、所得等）對於節能減排與GDP的影響。實證分析結果顯示，臺灣之能源消費、CO2排放，以及GDP對於各項政策工具與經濟變數之彈性不僅各異其趣，而且有些彈性並非固定不變，可隨時間經過動態調整。

Energy saving and emission reduction have become an issue commonly concerned by international communities as well as domestic policy makers. Since, in order to initiate effective policy to save energy and reduce emission, one needs to reasonably capture the potential impacts of various policy instruments on energy consumption, CO2 emission and economic growth, this paper, after extensively reviewing the literature, builds a locally ideal empirical model that facilitates the estimation of various policy elasticities. The empirical results indicate that policy elasticities may not only differ from one to the others, but also change dynamically, implying the 3E impacts of some policy instruments might be weakening over time.