京都機制下排放減量權證價格之經濟分析

An Economic Analysis of Price of Certified Emission Reductions under Kyoto Mechanism in Taiwan

1997年聯合國氣候變化綱要公約第三次締約國大會通過的京都議定書（Kyoto Protocol）中，明訂各種相關溫室氣體減量之措施及方法，其中指出清潔發展機制為減少全球溫室氣體之市場機制之一。本研究根據締約國在2003年12月所召開第九次締約國大會中決定排放減量權證計算方式來進行實證模擬分析，從經濟觀點出發，考慮我國與其他附件一國家之碳交易，分析我國之權證供給價格。本研究引入Olschwski et al。（2005）之模型，理論分析並實證模擬短期排放減量權證與長期排放減量權證價格。本研究之主要結論如下：（l）若我國之私有地主參與清潔發展機制且將農用土地改以造林，則可在第5、10、15年發行短期權證，其單位碳供給價格為每噸2, 664.88元，20年每公頃可發行323.24單位的短期權證，地主之碳收入現值為每公頃599, 360.9元。以本研究之模擬結果，我國作為賣方的供給價格為每噸2, 664.88元，約55.62歐元，明顯高於世界上一般的交易價格。（2）許多因素將影響交易價格，如減少農地之休耕補貼、在較便宜之土地造林，以及大規模造林降低造林成本等，則我國作為賣方之供給價格將會降低，例如當土地之機會成本減少25%時，則每單位權證將會降到1,775.62元，約為37.06歐元，較為接近世界之權證價格。（3）對買方而言，長期權證較有保障，購買誘因比短期權證高；但對賣方而言，由於長期權證下之土地利用彈性較低，故長期權證較不具交易誘因。反之，由於地主在發行短期權證下，可在較短期內改變土地利用型態，因此賣方會較偏好短期權證，而短期權證對買方則較不具誘因。然而，如果非附件一國家之折現率比附件一國家之折現率低，則對買賣雙方而言，長期權證均比短期權證更具交易之經濟誘因。 In 1997, the Third Conference of Parties (COP3) of the United Nations Framework Convention on Climate Change (UNFCCC) adopted Kyoto Protocol, which subscribed a variety of instruments and methods to reduce the emission of greenhouse gases. Among them, Clean Development Mechanism (CDM) is one of the market mechanisms to reduce global atmospheric CO2. Based on the new accounting rules concerning Certified Emission Reductions (CER), which were determined by the Ninth Conference of Parties (COP9) in December 2003, this study theoretically and empirically analyzes the carbon trading between Taiwan and other Annex 1 countries, and analyzes the CER supply price of Taiwan. The model used in this study is based on Olschewski et al. (2005). In addition to model development, a simulation is conducted to analyze the prices of temporary CER (1CER) and long-term CER (1CER) in Taiwan. The main conclusions of this study are summarized as follows: (1) If private agricultural landowners convert their agricultural land use to afforestation and participate in the CDM program, the land owners can issue tCER in the 5th, 10th and 15th year, and their unit carbon supply price is NT$ 2, 664.88 per ton. In the 20 years period, totally 323.24 units of tCER per hectare are issued, and the present value of the carbon income of landowners is NT$ 599, 360.9 per hectare. According to the simulation results in this study, the CER supply price of Taiwan as a CER supplier is NT$ 2, 664.88 per ton (about 55.62 Euros), which is significantly higher than the price level in the world. (2) Many factors would affect the CER trading prices, e.g., the reduction of subsidies on fallow agricultural land, afforestation on cheaper land, the reduction of afforestation costs due to large scale afforestation, and etc. For example, if the opportunity costs of land are increased by 25%, the CER per unit would be decreased to NT$ 1, 775.62 (about 37.06 Euros), which is close to the CER price level in the world. (3) Compared with purchasing tCER, purchasing ICER has fewer risks. Hence, demanders have higher incentives to buy 1CER than tCER. However, for suppliers, compared with issuing tCER, issuing 1CER will make land use less flexible, thus they have lower incentives to issue 1CER. Since landowners can convert their land use more easily by issuing tCER, normally they prefer issuing tCER, demanders however prefers to purchase ICER. If the discount rates of non-Annex countries are lower than those of Annex 1 countries, then, for both of the demanders and suppliers, they all have more economic incentives to trade 1CER than tCER.

In 1997, the Third Conference of Parties (COP3) of the United Nations Framework Convention on Climate Change (UNFCCC) adopted Kyoto Protocol, which subscribed a variety of instruments and methods to reduce the emission of greenhouse gases. Among them, Clean Development Mechanism (CDM) is one of the market mechanisms to reduce global atmospheric CO2. Based on the new accounting rules concerning Certified Emission Reductions (CER), which were determined by the Ninth Conference of Parties (COP9) in December 2003, this study theoretically and empirically analyzes the carbon trading between Taiwan and other Annex 1 countries, and analyzes the CER supply price of Taiwan. The model used in this study is based on Olschewski et al. (2005). In addition to model development, a simulation is conducted to analyze the prices of temporary CER (1CER) and long-term CER (1CER) in Taiwan. The main conclusions of this study are summarized as follows: (1) If private agricultural landowners convert their agricultural land use to afforestation and participate in the CDM program, the land owners can issue tCER in the 5th, 10th and 15th year, and their unit carbon supply price is NT$ 2, 664.88 per ton. In the 20 years period, totally 323.24 units of tCER per hectare are issued, and the present value of the carbon income of landowners is NT$ 599, 360.9 per hectare. According to the simulation results in this study, the CER supply price of Taiwan as a CER supplier is NT$ 2, 664.88 per ton (about 55.62 Euros), which is significantly higher than the price level in the world. (2) Many factors would affect the CER trading prices, e.g., the reduction of subsidies on fallow agricultural land, afforestation on cheaper land, the reduction of afforestation costs due to large scale afforestation, and etc. For example, if the opportunity costs of land are increased by 25%, the CER per unit would be decreased to NT$ 1, 775.62 (about 37.06 Euros), which is close to the CER price level in the world. (3) Compared with purchasing tCER, purchasing ICER has fewer risks. Hence, demanders have higher incentives to buy 1CER than tCER. However, for suppliers, compared with issuing tCER, issuing 1CER will make land use less flexible, thus they have lower incentives to issue 1CER. Since landowners can convert their land use more easily by issuing tCER, normally they prefer issuing tCER, demanders however prefers to purchase ICER. If the discount rates of non-Annex countries are lower than those of Annex 1 countries, then, for both of the demanders and suppliers, they all have more economic incentives to trade 1CER than tCER.