Today's world is facing a serious challenge of high carbon emissions. A large number of studies are examining the deteriorating impact of carbon emissions at the country or firm level, but the literature on the voluntary carbon disclosure project (CDP) by cities is not rich. Therefore, this study seeks to examine the effect of the population (Pop) and gross domestic product (GDP) on carbon emissions of cities by using data of CDP. The dataset refers to a set of numerous cities from around the world, spanning the period from 2012 to 2016. Random effects panel regression and generalized method of moments (GMM), and quantile regressions techniques have been employed to empirically investigate the discussed relationship and to control the potential endogeneity issues, respectively. According to the results, population and GDP are substantial predictors of carbon emissions in sampled cities. Findings show that not only factories contribute to increasing carbon emissions rate, but cities are equally responsible for these emissions as they put no checks on their economic growth and population. The findings are also robust for policy implications.

中文翻译：

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碳披露项目下城市温室气体排放自愿披露：一种可持续发展的方法

当今世界正面临高碳排放的严峻挑战。大量研究正在研究国家或企业层面碳排放恶化的影响，但关于城市自愿碳披露项目（CDP）的文献并不丰富。因此，本研究试图利用 CDP 数据来检验人口 (Pop) 和国内生产总值 (GDP) 对城市碳排放的影响。该数据集涉及来自世界各地的众多城市，跨越 2012 年至 2016 年。随机效应面板回归和广义矩法 (GMM) 以及分位数回归技术已被用于实证研究所讨论的关系并分别控制潜在的内生性问题。根据结果​​，人口和 GDP 是样本城市碳排放的重要预测因素。调查结果表明，不仅工厂对增加碳排放率有贡献，而且城市对这些排放负有同样的责任，因为它们不对经济增长和人口进行检查。研究结果对政策影响也很可靠。