推動自然碳匯溫室氣體自願減量專案成本評估—以造林與再造林及加強森林經營專案為例

Abstract

氣候變遷已成為全球重要議題，從1988年IPCC成立到《京都議定書》和《巴黎協定》的通過，各國政府積極減少溫室氣體排放。臺灣也響應全球趨勢，提出2050淨零排放目標，並擬定包括自然碳匯在內的多項關鍵戰略，並關注自然碳匯於抵減溫室氣體排放的潛力，以積極促成溫室氣體減量，而本研究旨在探討臺灣如何通過碳定價機制推動森林碳匯自願減量專案成本效益評估。 本文就碳減量機制及森林碳交易進行說明，並就碳定價機制通過對碳排放設定價格，引導企業減排。臺灣於西元2023年修訂《氣候變遷因應法》以碳定價機制概念推動溫室氣體自願減量專案。其中森林碳匯專案目前有造林及再造林，普遍國際間森林碳市場透過造林、撫育和疏伐等加強森林經營活動，增加的碳吸存量轉換為碳權額度轉賣給排放者，以抵減其排放量。 臺灣在推動自然碳匯工作之森林碳匯專案初期成本高、碳吸存效果需長期觀察，其專案成本效益挑戰高。本研究顯示，提高碳交易價格能顯著改善專案的淨收益，需著重控制造林成本和森林經營管理成本以提升經濟效益，而不同專案地點間的效益差異大，且經營面積規模越大，專案平均成本相對越低。以本研究柳杉森林碳匯專案在低碳收益的情況下難以獲得正收益，但隨著碳交易價格的提升，專案經濟效益會有顯著改善。為達到更好的經濟效益，需嚴格控制各項成本並提高碳收益，另外，研究結果顯示單位碳吸存成本的變動範圍較大，需在專案制定時謹慎考量。而透過強化私人營林經營效率和增加造林面積，能有效提升碳吸存量，並提供經濟誘因促使林主積極參與，然而碳匯專案的成本效益仍需考量各項不確定性及風險，如自然災害、管理難度等。 透過推動自然碳匯和碳定價機制，自然碳匯在減少溫室氣體排放中的潛力巨大，但其推動需要有效的經濟誘因和政策支持。未來可透過改進碳匯專案的管理和技術，並結合經濟誘因機制，將有助於達成臺灣實現2050淨零排放目標。

Climate change has become a critical global issue. Since the establishment of the IPCC in 1988 and the adoption of the Kyoto Protocol and the Paris Agreement, governments worldwide have been actively working to reduce greenhouse gas emissions. Taiwan has responded to this global trend by setting a target of achieving net-zero emissions by 2050 and formulating several key strategies, including carbon sinks. This strategy focuses on the potential of carbon sinks to offset greenhouse gas emissions, thereby actively promoting emission reductions. This study aims to explore how Taiwan can promote the cost-effectiveness of voluntary forest carbon reduction projects through carbon pricing mechanisms. This paper explains the carbon reduction mechanisms and forest carbon trading. It discusses how carbon pricing mechanisms set a price on carbon emissions to guide companies in reducing their emissions. In 2023, Taiwan amended the Climate Change Response Act to promote voluntary greenhouse gas reduction projects using the concept of carbon pricing mechanisms. Currently, forest carbon sink projects in Taiwan include afforestation and reforestation. The international forest carbon market typically enhances forest management activities such as afforestation, cultivation, and thinning to increase carbon sequestration. This increased carbon sequestration is converted into carbon credits sold to emitters to offset their emissions. In promoting natural carbon sinks, Taiwan faces high initial costs and long-term observation requirements for forest carbon sink projects, presenting significant cost-effectiveness challenges. This study shows that increasing carbon trading prices can significantly improve the net benefits of these projects. It is essential to control afforestation costs and improved forest management costs to enhance economic efficiency. The benefits vary significantly across different project locations, and larger management areas result in lower average project costs. The study on the Taiwan Cryptomeria japonica forest carbon sink project shows that achieving positive returns is challenging under low carbon prices. However, as carbon trading prices rise, the project's economic efficiency significantly improves. To achieve better economic efficiency, strict cost control and increased carbon revenue are necessary. Additionally, the study results indicate a wide range of unit carbon sequestration costs, requiring careful consideration during project planning. Enhancing private forest management efficiency and increasing afforestation areas can effectively improve carbon sequestration, providing economic incentives for forest owners to participate actively. However, the cost-effectiveness of carbon sink projects must also consider uncertainties and risks such as natural disasters and management difficulties. Promoting carbon sinks and carbon pricing mechanisms reveals a significant potential for reducing greenhouse gas emissions, but it requires effective economic incentives and policy support. Improving project management and technology, combined with economic incentive mechanisms, will contribute to achieving Taiwan's 2050 net-zero emissions target.