本研究採用時間序列分析法，研究調查八大工業國家在GDP、能源消耗與CO2排放之間的動態關係，並佐以驗證環境顧志耐假說在八大工業國的有效性。本研究選用1970至2012年間的年度數據資料(俄羅斯選自1989至2012年)，並利用共整合檢定與Granger因果關係檢定用以探討變數之間的動態關係。
本研究在德國與俄羅斯的實證結果支持環境顧志耐假說成立，然而在日本的結果則顯示GDP與CO2排放之間存在U型的曲線關係。實證結果在法國、德國與美國觀察到從GDP到能源消耗的負向Granger因果關係，然而在英國與俄羅斯則發現到從能源消耗到GDP的正向因果關係。此外，本研究也發現從GDP到CO2排放的負向因果關係存在於德國、義大利與美國。
This study employs time series approach to investigate the dynamic relationships among gross domestic product (GDP), energy consumption, and carbon dioxide emissions (CO2) and examine the validity of environmental Kuznets curve (EKC) hypothesis for G8 countries. Using annual data for the period from 1970 to 2012 except Russia only from 1989 to 2012, the dynamic causal relationships were tested utilizing Cointegration test, and Granger causality test based on Vector Autoregressive Model (VAR). The empirical results support that the validity of EKC hypothesis in Germany, and Russia but the evidence in Japan shows a U-shaped relationship between GDP and CO2 emissions. The empirical findings found a negative Granger causality running from GDP to energy consumption in France, Germany, and the US, and a positive Granger causality running from energy consumption to GDP in UK, and Russia is also found. Furthermore, this study also explores a negative causal relationship from GDP to CO2 emissions in Germany, Italy, and the US.
