Contributors to the carbon emissions of metropolises at different development levels

Abstract

The urbanization process of metropolises in China has accelerated in recent years, with the number of urban residents increasing by 21 % per decade (21 %/10a) and the per capita gross domestic product (per capita GDP) increasing by 120 % per decade (120 %/10a) from 2000 to 2019. In parallel with this rapid economic development, carbon emissions have greatly increased, rising by 141 % in 20 years. Understanding the carbon emission trend and its influencing factors is necessary to find plausible pathways for decarbonization. Using data from the Carbon Emission Accounts and Datasets (CEADs), this study analyses the spatiotemporal variations in urban carbon emissions from 2000 to 2019 via the ridge regression method, and the STIRPAT model is adopted, with provincial capitals in China as an example. The cities are classified into three stages of development (i.e., developed, developing and least developed cities) according to per capita GDP to explore the discrepancy in carbon emissions and influencing factors across different types of cities. (1) Urban carbon emissions show a fluctuating upwards trend for the overall sample, with yearly growth rates of 8 % per annum (8 %/a) for 2000–2009 and 2 % per annum (2 %/a) for 2010–2019. (2) For developed cities, affluence is the most significant influencing factor, followed by urbanization rate and energy intensity. In developing cities, carbon emissions initially increased rapidly and then presented a decelerating growth rate, with the main influencing factors being affluence, energy structure and industry structure. In the least developed cities, carbon emissions present a persistent increasing trend and are influenced mainly by affluence, energy structure and urbanization rate. (3) To coordinate economic benefits and carbon emissions, developed cities need to focus on reducing energy consumption, whereas developing cities need to accelerate energy and industrial transformation. For the least developed cities, strong emission reduction efforts may start later for socioeconomic reasons.