國際碳排放責任分擔之跨國比較分析

A Cross-Country Comparison of Responsibility Sharing in International Carbon Emissions

國際碳排放之責任歸屬一直是一個熱門且爭議的話題，本文採用一個多國產業關聯的架構，利用歐盟所編製的多國投入產出資料庫 (WIOD)，進行不同觀點之國際碳排放責任分擔設算，並分析不同類型之國家所承擔責任隨時間之變化情況。實證結果發現，以人均碳排放及碳密集度作為分擔基準時，大部分已開發國家在Zhou et al. (2010) 的責任分擔原則下會較為有利，而新興工業化國家則是在Marques et al. (2012) 的收入或所得觀點下承擔相對較少的責任。我國方面，若採消費者責任分擔方式所需承擔的排放責任最小，而以Zhou et al. (2010) 的原則計算時所需承擔的排放責任最高，其次則為收入觀點責任，顯示我國不只需要有效提升能源使用效率以降低生產過程的碳排放，還需要想辦法調整出口地區結構，盡量以採用清潔生產技術之國家為出口對象，才能夠減低可能需要承擔之排放責任。本文也發現，Marques et al. (2012) 以所得為基礎的責任分擔原則因係從國家所得的觀點分配各國之碳排放責任，相對上較為有效及公平。在此原則下，已開發國家將會尋找對環境影響最小的地方進行生產，新興國家則有動力降低其產品之碳密集度，且採用清潔生產技術的國家之貿易選擇機會也會比較多。

Responsibility sharing in international carbon emissions has been a hot and controversial issue in recent days. This paper applies the World Input-Output Database (WIOD) developed by the European Union to compute the share of responsibility of carbon dioxide emissions for 41 countries based on five responsibility-sharing principles, over the period of 1995-2009. Our results show that developed countries will benefit most under the principle proposed by Zhou et al. (2010), while newly-developed countries will favor the sharing principle by Marques et al. (2012), which accounts the shared responsibility based on the income being received from trade. For Taiwan, the most favorable one will be that based on consumption of goods and services. Conversely, it will be responsible for more emissions under the income-based principle. This implies that Taiwan not only needs to improve its energy efficiency effectively to reduce the emissions from production, but also needs to adjust its area mix of exports to avoid the added responsibility from exporting. We also find that the income-based principle proposed by Marques et al. (2012) is relatively fair and efficient as compared to other principles. Under the principle, developed countries will have the incentive to move their production to places having less environmental impacts. Newly-developed countries will also have the motive to reduce their products’ carbon intensity, while countries pursuing clean production technologies will have more opportunities in choosing trading partners.