Climate change, human impacts, and carbon sequestration in China

The scale of economic growth in China during the past three decades is unprecedented in modern human history. China is now the world’s second largest economic entity, next to the United States. However, this fast economic growth puts China’s environment under increasing stresses. China can be viewed as a massive “laboratory” with complex interactions between socioeconomic and natural systems, providing an excellent opportunity to examine how environmental changes and intensive human economic activities influence natural systems. This special feature explores the impacts of climate change and human activities on the structure and functioning of ecosystems, with emphasis on quantifying the magnitude and distribution of carbon (C) pools and C sequestration in China’s terrestrial ecosystems. We also document how species diversity, species traits, and nitrogen (N) and phosphorus (P) stoichiometry mediate ecosystem C pool and vegetation production. This overview paper introduces the background and scientific significance of the research project, presents the underlying conceptual framework, and summarizes the major findings of each paper. Reducing CO2 emissions to mitigate regional and global climate change is one of the most challenging issues facing humanity (1). At present, China has the largest annual CO2 emissions in the world (Upper graph in Fig. 1), placing it in the spotlight of efforts to manage global C emissions and design climate-change policy. It is therefore critical to improve our understanding of the C budget and its dynamics in China to mitigate climate change at both regional and global scales. Fig. 1. Evolution in total national GDP, population, and fossil fuel CO2 emissions, together with trajectory of the national policies in China between 1945 and 2015. (Upper) GDP, population, and CO2 emissions. The CO2 emissions data were from Oak Ridge National Laboratory (cdiac. ess-dive. lbl. gov/), and population and GDP data from the World Bank (https: //data. worldbank. org/country/). (Lower) National … ↵11To whom correspondence may be addressed. Email: jyfangaturban. pku. edu. cn, fangjingyunatibcas. ac. cn, or terry. chapinatalaska. edu. 1: #xref-corresp-1-1