International experience of carbon neutrality and prospects of key technologies: Lessons for China

Carbon neutrality(or climate neutrality) has been a global consensus, and international experience exchange is essential. Given the differences in the degree of social development, resource endowment and technological level, each country should build a carbon-neutral plan based on its national conditions.Compared with other major developed countries(e.g., Germany, the United States and Japan), China's carbon neutrality has much bigger challenges, including a heavy and time-pressured carbon reduction task and the current energy structure that is over-dependent on fossil fuels. Here we provide a comprehensive review of the status and prospects of the key technologies for low-carbon, near-zero carbon, and negative carbon emissions. Technological innovations associated with coal, oil-gas and hydrogen industries and their future potential in reducing carbon emissions are particularly explained and assessed. Based on integrated analysis of international experience from the world's major developed countries, in-depth knowledge of the current and future technologies, and China's energy and ecological resources potential, five lessons for the implementation of China's carbon neutrality are proposed:(1)transformation of energy production pattern from a coal-dominated pattern to a diversified renewable energy pattern;(2) renewable power-to-X and large-scale underground energy storage;(3) integration of green hydrogen production, storage, transport and utilization;(4) construction of clean energy systems based on smart sector coupling(ENSYSCO);(5) improvement of ecosystem carbon sinks both in nationwide forest land and potential desert in Northwest China. This paper provides an international perspective for a better understanding of the challenges and opportunities of carbon neutrality in China,and can serve as a theoretical foundation for medium-long term carbon neutral policy formulation.