臺灣農業部門溫室氣體排放趨勢推估──動態可計算一般均衡模型之應用

GREENHOUSE GAS (GHG) BASELINE FORECASTING FOR TAIWAN'S AGRICULTURAL SECTOR USING THE DYNAMIC COMPUTABLE GENERAL EQUILIBRIUM (CGE) APPROACH

環保署於 2017 年 3 月 28 日公告《溫室氣體階段管制目標及管制方式 作業準則》中指出， 中央各部會應訂定部門別的溫室氣體排放趨勢推估及參 數， 並進行溫室氣體排放趨勢推估及情境分析， 作為積極減碳分工佈局的依 據。本研究的主要目的為建立我國農業部門溫室氣體排放基線與未來相關 因應政策模擬分析， 主要是採用由中央研究院永續科學中心與澳洲農業與資 源經濟局（ABARES）共同研發的動態可計算一般均衡模型及資料庫， 並於 農業部門做調整延伸， 考量未來我國經濟成長與農業政策目標， 評估我國農 業部門未來之溫室氣體排放趨勢， 並同時檢視其對於經濟面、能源面、社會 面與環境面所帶來的衝擊影響。本文的特色為根據 2017 年中華民國溫室氣 體排放清冊報告， 將農業部門的排放範疇區分為農林漁牧之能源及電力消費 排放（簡稱燃料燃燒）與非燃料燃燒兩大類。另外， 本文考慮兩種情境的設計， 分別為基準情境: 考量目前已規劃之未來農業政策; 政策情境: 提高糧食自給 率達 40% 目標， 分別評估在不同情境下的農業部門溫室氣體排放趨勢。本文 的另一特色為著重於「由下而上」的政策研究方法， 透過與農委會各業務單 位（包含農林漁牧）與農業相關學者專家之反覆討論不同的情境設計，共同檢 視基礎數據並進行參數校準， 使得本文所推估之未來農業部門溫室氣體排放 趨勢更趨合理並符合實際。

'Regulations for Periodic Regulatory Goals and Approaches of the Greenhouse Gas Emissions'', issued by Taiwan's Environmental Protection Administration, indicate that the central competent authority shall consult with the central industry competent authorities to determine the national greenhouse gas (GHG) emission trend projection principles and parameters as well as to project GHG emission trends and to provide scenario analysis. The major purpose of this study is to establish the methodology and provide the baseline forecasting and related policy simulations of greenhouse gas emissions in Taiwan's agricultural sector. We use the dynamic computable general equilibrium (CGE) modularization system-GEMTEE (General Equilibrium Model for Taiwan Economy and Environment), developed jointly by the Centre for Sustainability Science, Academia Sinica and the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES). The GEMTEE modularization system is applied in the agricultural sector for considering the future economic growth and agricultural policy objectives of Taiwan, forecasting the future GHG emission trends of the agricultural sector, and evaluating its impact on the economic, energy, social and environmental aspects via experts' consultation workshops. Based on the 2017 Taiwan Greenhouse Gas Inventory Report, the GHG emission of the agricultural sector is divided into two categories: fuel and electricity consumption in agriculture, forestry, fishery, and animal husbandry (referred to as fuel combustion) and non-fuel combustion with the sources of emissions mainly being methane and nitrous oxide produced by agricultural production activities, livestock gastrointestinal fermentation and excreta treatment. Moreover, we consider the design of two scenarios, which are (1) the baseline scenario: considering the current planned agricultural policy only; (2) policy scenario: increasing the self-sufficiency rate of food to 40%, and assessing its GHG emission trends. Another feature of this paper is the ''bottom-up'' approach. Through experts' consultation workshops (including experts on agriculture, forestry, fishery and animal husbandry), we discuss different scenario designs and jointly review the basic data set. Parameter calibration is carried out, which makes the future trend of GHG emission in the agricultural sector reasonable and realistic.