Definition of variables.

This study examines how various environmental and economic variables contribute to environmental degradation. Industrialization, trade openness, and foreign direct investment are among the variables, as are environmental diplomacy, environmental diplomacy secure, and renewable energy consumption. Therefore, the data covers the years 1991–2020, and our sample includes all 19 countries and two groups (the European Union and the African Union). The research used the Pesaran CD test to determine cross-section dependency, CIPS and CADF test to determine stationarity, the Wald test for hetrodcedasasticity and the Wooldridge test for autocorrelation; therefore, VIF for multicollinearity, Durbin and Hausman to analyze the endogeneity. It also employed Westerlund’s cointegration test to ensure cross-sectional dependence, Wald test for group-wise heteroscedasticity, Wooldridge test for autocorrelation, VIF for multicollinearity, and Durbin and Hausman for endogeneity. The two-step system generalized method of moments (GMM) is used to estimate the results and confirm the relationship between independent variables (Industrialization, trade openness, FDI, environmental diplomacy, secure environmental diplomacy, and renewable energy) and dependent variables (Environmental Degradation) in G20 countries. Therefore, Industrialization, trade openness, foreign direct investment, ecological diplomacy, and renewable energy consumption significantly impact ecological degradation. Environmental diplomacy is crucial to combat degradation and stimulate global collaboration. G20 nations enact strict environmental restrictions to tackle climate change and encourage economic growth.

本研究旨在考察各类环境与经济变量对环境退化的驱动作用。研究涉及的变量包括工业化水平、贸易开放度（trade openness）、外商直接投资（foreign direct investment, FDI），以及环境外交、保障性环境外交（secure environmental diplomacy）与可再生能源消费。本研究的数据覆盖1991年至2020年，样本包含全部19个主权国家以及欧盟（European Union）和非洲联盟（African Union）两个区域集团。本研究采用Pesaran CD检验判定截面相关性，使用CIPS检验与CADF检验确定序列平稳性，以Wald检验检验异方差性，Wooldridge检验检验自相关性，通过方差膨胀因子（variance inflation factor, VIF）诊断多重共线性，并借助Durbin检验与Hausman检验分析内生性问题。此外，本研究还运用Westerlund协整检验验证截面相关性，重复采用Wald检验检验分组异方差性、Wooldridge检验检验自相关性、方差膨胀因子（VIF）诊断多重共线性，以及Durbin检验与Hausman检验分析内生性。本研究采用两步系统广义矩估计法（two-step system generalized method of moments, GMM）对模型进行估计，以验证G20成员国中各自变量（工业化水平、贸易开放度、外商直接投资、环境外交、保障性环境外交与可再生能源消费）与因变量（环境退化）之间的关联。研究结果表明，工业化水平、贸易开放度、外商直接投资、环境外交以及可再生能源消费对环境退化具有显著影响。环境外交对于遏制环境退化、推动全球环境协作至关重要。G20成员国通过制定严格的环境规制以应对气候变化并促进经济增长。