台灣減碳策略下電力業之健康共同效益評估

Abstract

近十餘年來，溫室氣體(Green House Gases, GHGs)排放所造成的全球暖化，衍生出經濟、社會、生態等多方面的環境問題，致使全球對於低碳排放發展策略（Low-Emission Development Strategies, LEDS）的發展方向已經趨於明朗。然而，過去溫室氣體與傳統空氣污染物多被視為兩個領域，單獨被分析或評估對環境造成的衝擊，但若依循減碳、低碳的策略前進，其所發展的技術與政策，不但減少了溫室氣體的排放量，同時也能直接或間接減少其餘空氣污染物的排放量，而致使空氣品質的改善，獲得健康效益。 台灣現有電力發電業的碳排占了整體超過六成的比例，又電力業也是傳統污染物排放的大宗。本研究利用TWIEA模式與AERMOD大氣擴散模型，建立起台灣電力業健康共同效益評估方法，評估當台灣施行現有減碳策略或更積極的策略下，電力需求的改變與發電結構的調整，是否能使電力業溫室氣體排放下降，也一併造成傳統汙染物(SOX、NOX、PM10)排放量改變，其產生的健康共同效益，以縣市別與全國來呈現結果。 結果顯示:若遵行現有的減碳策略，2020年是無法達成電力部門的減碳目標的，並且PM10的排放量會高過於2005年。唯有進行積極減碳的策略，2020年時方能在電力部門達成減碳目標，並讓SOX、NOX、PM10三種傳統汙染物總體排放量皆能下降，進而獲得較高的健康共同效益(相較既有策略提升15.6%)。此外，又因全國總排放量與全國總健康影響並非一定呈現正向關係，故透過縣市層級的健康共同效益評估方法會優於僅用國家層級的解析度。本研究中，若施行更積極的減碳策略，獲得較大實質健康共同效益的城市依序為:大台中市、大高雄市、基隆市、新北市、彰化縣與雲林縣。 關鍵字：電力業，減碳策略、傳統空氣汙染物、健康共同效益

Green House Gases emission has induced global warming, which results in economic, social, ecological and other aspects of environmental problems over the past decades. The direction of Low-Emission Development Strategies then has become clear. However, in the past the issues of greenhouse gases and conventional air pollutants are considered two individual fields to be analyzed concerning the impact on the environment. Following the low-carbon strategy, the development of its technology and policy will not only reduce greenhouse gas emissions, but also can directly or indirectly lower the emissions of conventional air pollutants, improving air quality, and obtaining health benefits. Taiwan's current carbon emission from power generation sector accounts for over 60% of the overall emission.Additionally, the power generation sector exhausts a lot of conventional pollutants. This study used TWIEA model and AERMOD atmospheric dispersion model to establish Taiwan's power sector health co-benefits assessment methods, and assess the existing carbon reduction strategies implemented in Taiwan. The more aggressive strategies in which the demand of electric power and power generation structure changes are evaluated as to whether the CO2 and conventional pollutants (SOX, NOX, PM10) emissions could be lowered. Then, this study analyzes the health co-benefits at urban and national levels. The results show that under the existing carbon reduction strategies, we are unable to reach the target of carbon reduction in power sector in 2020, and PM10 emissions will be higher than those in 2005. The only way to reach the goal in 2020 and abate SOX, NOX, PM10 emissions is to adopt more aggressive strategies, which will obtain higher health co-benefits (relatively being improved by 15.6%, compare with the existing policy). In addition, the national total emissions and the national total health effects are not necessarily positively related, so using the county-level resolution to assess health co-benefits will be better than just using the national-level resolution. In conclusion, the implementation of more aggressive carbon reduction strategies would lead to higher degree of health co-benefits for cities in order as following: Taichung city, Kaohsiung city, Keelung city, New Taipei City, Changhua County and Yunlin County. Keywords: Power sector, carbon reduction strategies, Conventional air pollutants, Health co-benefits