核能大國之二氧化碳、核能與經濟成長之關聯性分析

Abstract

2008年全球金融海嘯導致各國GDP下降，經濟復甦成為了當前課題，但追求高的經濟成長，就必要投入高度的能源做支持，目前的傳統石化能源已無法支撐，因此勢必須開發非傳統性能源。但一般能源對環境的傷害極大，在環保意識抬頭的情況下，許多國家受到國際公約的規範(京都議定書中，2012年為履行第一次的承諾目標的截止年)，所以為了達到二氧化碳減量目標以符合京都議定書中的要求，各國紛紛控制一般能源的使用，積極投入乾淨能源的開發，然而各國雖然積極倡導及研究綠色能源，但在技術層面上仍需突破，故核能成為目前全球主要的能源來源之一。核能雖然安全但始終是有威脅性，在2011年日本福島核災發生後，各國對核能的使用產生疑慮，雖然各國多數仍繼續使用核能發電，但對於核能的使用抱持著又愛又恨的態度。因此在經濟成長、環境保護、能源短缺以及核能安全性的矛盾之下，他們之間的因果關係是非常值得深入研究。 本研究探討二氧化碳排放量，核能消費量和實質GDP之間的動態因果關係，研究以2011年最新資料所顯示的核能發電量前十大國家為對象，其依序是美國、法國、日本、俄羅斯、南韓、德國、加拿大、烏克蘭、中國、英國，並因各國的背景資料差異很大，故將這十國依據G8代表的八大工業國分類成兩群: 工業國群:美國、法國、日本、俄羅斯、德國、加拿大、英國 非工業國群:南韓、烏克蘭、中國 研究期間工業國群為1980-2009年、非工業國群為1992-209年之間，利用面板單根檢定、面板共整合檢定、和ECM模型，計算出變數間長期與短期的因果關係。 在工業國群，實質GDP對核能源消費量的估計係數有統計顯著且正面的影響;此外，雙向短期因果關係存在於實質GDP與二氧化碳排放之間和核能消耗量與二氧化碳排放間。我們可以說在短期內，如果實際GDP產生變化，這也將使核能消費量產生波動，而當核能源消耗增加1％，二氧化碳排放量將減少0.033％。另一方面在非工業國群短期關係中，只有一個因果關係，其為二氧化碳排放量對核能消費量的積極影響，在5％的顯著水準下為顯著。這意味著，當二氧化碳排放量增加1％，核能消費量也將在短期內增加1％。而長期的因果關係存在與否，則由ECT係數是否顯著而定。在工業國群中，ECT的係數在二氧化碳排放量與實質GDP方程式中分別以5％的水準，10％的水準下顯著；而非工業國群，ECT的係數在二氧化碳排放量與核能消耗量方程式中分別以1％和5％顯著水準下顯著。 總體而言，工業化國家的能源政策制定者可以透過促進核電廠的建立或增加核能消費來推動實質GDP的成長與減少二氧化碳的排放，且短時間內就具有顯著的效果。而非工業國家，制定者可透過增加能源投資和能源效率，加強節能政策，達到既減碳又不影響GDP的目標，此外節能也可減少不必要的能源浪費，並降低國家碳密度與能源密度的程度。未來研究可以預測核能在工業國家和非工業化國家的後續發展。

Nuclear energy has been a main energy source in the world. It has a stable cost, which do not fluctuate according to the real oil price and free of CO2 emission which can help to reduce GHG production. Besides, it is the only solution to save the problems, such as oil price rising, global warming, the shortage of energy and so on, which all the countries face up to. Therefore, Nuclear energy is deserved to be mentioned. This study examines dynamic causal relationships between pollutant emissions, nuclear energy consumption and real GDP for two panels of the top 10 nuclear power countries categorized into two separate sets which are industrial and non-industrial country group over the period 1980-2009 and 1992-2009 respectively. Among industrial country group, we adopt the data in U.S., France, Japan, Russia, Germany, Canada, and U.K.; as for non-industrial country group, the variables in South Korea, Ukraine, and China are included. We introduce panel unite root test, panel cointegration test, and ECM models to figure out the long- and short-term relationships among the variables in two different groups. In industrial country group, the estimated coefficients for real output to nuclear energy consumption are statistically significant and have positive impact; besides, bidirectional short-run causalities exist between real output and emissions, and between nuclear energy consumption and emissions. We can say that if real GDP changes, it will lead to the fluctuate of nuclear energy consumption, and when nuclear energy consumption increases 1%, emissions will decreases 0.033% in the short run. In non-industrial country group in the short-run, only one causality relationship in it, that is statistically significant at 5% level and positive impact from emission to nuclear energy consumption. It means that when emission increases 1%, then nuclear energy consumption will also increase 1% in the short run. With regard to long term relationship, the coefficients of ECT are significant at 5% level and 10% level respectively in emission and GDP equations in industrial country group, and they are significant at 1% and 5% respectively in nuclear energy consumption and emission equation in non-industrial country group. Overall, industrial countries’ energy policy makers could build more nuclear plants or increase nuclear energy consumption to push the growth of real GDP and to decrease the emission which has distinguished result in a short time. Then, in non-industrial countries, they can increase both energy supply investment and energy efficiency, and step up energy conservation policies to reduce unnecessary wastage of energy. Future research could forecast the development of nuclear energy in industrial countries and in non-industrial countries.