縣市低碳發展效率評估與其影響成因之探討

Evaluating the Low-Carbon Efficiency of the City and Analyzing Its Influential Factors

面對全球暖化之課題與威脅，各國政府大多以低碳發展，作為發展的訴求及目標。而縣市於發展中，雖產生許多效益，卻也消耗不少資源，連帶也產生不少碳排放量與環境污染，因此，地方政府在獲得規劃管理權限後，如何在永續及低碳的框架中，綜合地衡量各種效益與耗損，調和並予以共存，並且落實於縣市發展政策之中，亦為一重要之課題。目前在低碳發展上的評估，多採用指標評估的方式進行分析，且甚少考慮發展所產生的負的外部性（即非意欲產出，undesirable outputs），亦多將非意欲產出忽略不計，故在評估上存在許多侷限與缺失；此外，對於影響低碳發展效率之政策或成因亦未有深入探討。故本文以台灣各縣市作為實證案例，在考量非意欲產出下（碳排放威脅、環境污染衝擊），透過「資料包絡分析」（data envelopment analysis, DEA）中的不良產出模型，評估縣市低碳發展效率，並藉由Tobit 模型，釐清低碳政策對縣市低碳發展效率之影響效果，以作為未來低碳發展或政策研擬之參考。根據不良產出模型的評估結果，顯示臺北市、新竹市、臺東縣、花蓮縣在低碳發展效率上相對具有效率，且已達最適規模水準。另外，透過Tobit 模式的實證分析，對於影響縣市低碳發展效率具顯著的變數，包括工廠家數、資源回收量、市區公車系統路線總長、具綠建築標章的建物數、綠地面積。其中，除工廠家數對縣市低碳發展效率有負向影響外，其餘變數皆呈正向影響效果。

Facing the disasters and threats stemming from global warming and climate change, most city governments in the world have set up low-carbon development as a goal, and drawn up low-carbon policies to achieve this goal. However, the effects of those low-carbon policies are not possible to clarify. The development of the city/county has brought about economic benefits, but it also consumed significant resources and produced carbon emissions and environmental pollutants. Therefore, how to evaluate benefit and loss comprehensively and offer improvable recommendations is a key issue in the sustainable and low-carbon development of the city/county. In the past, most researchers evaluated low-carbon efficiency by indicators, and proceeded to their evaluation without considering the negative externalities arising from development, therefore, making inaccurate assessments of low-carbon efficiency evaluation. Thus, this paper assesses the low-carbon efficiency of the city by the Bad Outputs model of the DEA, and analyzes its influential policies by the Tobit model. According to the results of the Bad Outputs Model, Taipei City, Hsinchu City, Taitung County, and Hualien County are efficient, and have achieved an optimal scale level. Another result of the Tobit model indicates that the industrial unit has a negative impact on the low-carbon efficiency of the city. Moreover, resource recovery, the total length of the urban bus route, green buildings, and green areas all have a positive impact on the low-carbon efficiency of the city.