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Cities and urban agglomerations are carriers of greenhouse gas emissions and show significant heterogeneity. China has entered a transitional period of new-type urbanization, which emphasizes high-quality and coordinated regional development. However, evidence of the spatiotemporal heterogenous effects of new-type urbanization on carbon emissions in cities, and especially in urban agglomerations are still lacking. This study estimated the new-type urbanization level and investigated its spatiotemporal heterogenous impacts on carbon dioxide emissions (CO₂) in 288 Chinese cities and 18 urban agglomerations. The results show that for each 1% increase in new-type urbanization level, the median estimation of CO₂ emissions per capita can decrease by 171.0% (46.8%,338.4%) at city-level. The inverted "U-shaped" relationships between new-type urbanization and CO₂ emissions per capita were observed in more than 60% of the cities. The average impacts of new-type urbanization and its square term of the cities which are located in urban agglomerations are estimated to be approximately 0.8 and 1.7 times of cities that are not, which indicates that cities in urban agglomerations are peaking their CO₂ emissions per capita with a higher enhancement of new-type urbanization. The results add new insights for formulating dynamic phase-to-phase carbon reduction policies and urban planning in cities and urban agglomerations. [Display omitted] [ABSTRACT FROM AUTHOR]

Understanding the different impacts of urbanization on sectorial carbon dioxide (CO 2) emissions at different spatial scales is of great importance for the evaluation of energy transition policies and reduction of environmental inequality. However, how urbanization affects the CO 2 emissions of central heating systems at high spatial resolution in China has not been fully studied before. Based on satellite-observed NPP-VIIRS nighttime light (NTL) data, we develop a 5 km × 5 km annual CO 2 emission inventory for coal boilers, thermal power plants (TPPs), and natural gas boilers in China's central heating systems for the period 2012–2017 by using the geographical and temporally weighted regression (GTWR) model. It is observed that nonurban areas generated 2–4 times the CO 2 emissions of coal boilers in urban areas. The largest increments of CO 2 emissions of gas boilers are observed in urban areas of the eastern (6.80 times) and central regions (2.86 times) in 2013–2014, due to the clean heating policy in the "2 + 26" cities in China. The effects of urbanization on CO 2 emissions from natural gas boilers are approximately 2–3 times those of coal boilers, and the differences are largest in western cities with only minor differences in northeastern cities. Our results will aid in designing low-carbon development goals and provide micro-level information on central heating facilities in urbanized and less developed regions. Image 1 • Gridded CO 2 emissions inventory of central heating systems in 2012–2017 is developed. • The nighttime light data is used to downscale the prefecture-city level emissions. • A GTWR model is built to explore the spatio-temporal heterogeneity among cities. • City development has larger impacts on CO 2 emissions from gas-than coal-boilers. [ABSTRACT FROM AUTHOR]