Since China's carbon peak and carbon neutrality goals were put forward, photovoltaic power generation has gradually become one of the important fields to accelerate low carbon transition. Through the analysis of spatio-temporal distribution, competitive development and emission reduction of China's photovoltaic power generation, the main conclusions can be drawn as follows: (1) From 2012 to 2020, the total installed photovoltaic capacities increased from 6.25 million kW to 253.17 million kW, dominated by centralized power stations. (2) Regions including Shandong, Jiangsu, Anhui, Henan, and Shanxi showed a high-high autocorrelation, while regions such as Guizhou showed a high-low autocorrelation. (3) Electricity consumption, carbon emissions, and R&D investment were the positive driving factors for the growth of photovoltaic installed capacities, and R&D investment had a positive impact on the growth of photovoltaic installed capacities in neighboring provinces. (4) The potential emission reduction benefits per year of China's existing photovoltaic installations could almost reach 2.0E+08 tons and the accumulated emission reduction benefits could reach 19.2E+08 tons by 2030, revealing significant emission reduction potentials for promoting the achievement of carbon peak and carbon neutrality goals.

A system dynamics model of carbon dioxide emissions was constructed by analyzing the relationship among the influencing factors of carbon dioxide emissions and the main paths of carbon emission reduction. On this basis, the impact of four scenarios on carbon dioxide emissions were forecasted by regulating the economic growth rate of the supply side, energy structure and industrial structure so as to further discuss the contribution of major departments of carbon dioxide emission reduction. Results show that the trend of the net growth of carbon dioxide emissions slows down year by year among the four schemes. This trend plays a positive role in reducing carbon dioxide emissions through adjusting the speed of economic growth, improving energy structure and optimizing industry structure after that the net carbon emission achieves the peak. Compared with the speed of economic growth and the optimization of industry structure, the improvement of energy structure makes a greater contribution to reducing carbon dioxide emissions. Under the scheme of comprehensive regulation of the speed of economic growth, improvement of energy structure and optimization of industrial structure, net emissions of carbon dioxide will reach the peak (10.445 billion tons) in 2024 and achieve the carbon neutrality in 2058 in China, which matches with the current situation.

The Anthropocene indicates that human activities have exerted a significant influence on the earth system. With rapid increases in carbon emissions and changes in the underlying surface, the global process of large-scale urbanization has exacerbated the negative impact on the earth's surface and undermined the earth's habitability. Carbon neutrality is not only the international consensus on climate change, but also a key measure to build a habitable earth. Based on multi-source data, the geographical process and pattern evolution of global urbanization are analyzed in terms of multi-dimensional spatiotemporal characteristics, and the correlation between carbon emissions and urbanization is preliminarily analyzed. The main conclusions are as follows: (1) With global urbanization process continuing to advance, the demographic structure of urban and rural areas shows a divergent trend. Meanwhile, the global city scale has an overall growth, the hot spots of which are concentrated in Southeast Asia and Eastern Central Africa, and more people worldwide are living in large cities. (2) Global urban land increased significantly, from 364000 km² in 1992 to 793000 km² in 2018, with a growth rate of 126.0%. During the same period, Asia accounted for 45.4% of the growth and was the leading region of the world's urban land expansion. (3) With rapid urbanization, global energy carbon emissions have grown rapidly, reaching 37.67 billion tons in 2018 and 21.91 billion tons of carbon dioxide since 1970, of which the structural power sector accounted for 45.8% of the growth and the Asian region accounted for 84.3%. The correlation between urbanization rate, per capita GDP and per capita carbon emissions showed different characteristics, and obvious heterogeneity among groups with high urbanization rates and among high-income countries. We call for the establishment of interdisciplinary collaborative research to explore the relationship between livable earth, carbon neutralization and global sustainable urbanization, to recognize the potential of sustainable urbanization for carbon neutrality goals.