| The effect of urbanization on carbon emissions | Authors | Research setting |
| Positive | Gouldson & Murphy (1997) York et al. (2003) York (2007) Liddle & Lung (2010) Lin & Liu (2010) Usama Al-mulali et al. (2013) Ponce & Maishall (2014) Wang & Shao (2014) Peng et al. (2016) |
137 counties 14 EU nations 17 developed countries China MENA countries 80 countries China China |
| Negative | Pachauri & Jiang (2008) Alexiadis 2012 | India & China |
| Nonlinear | Li et al. (2014) Zhang et al. (2017) He et al. (2017) | China OECD countries China |