Recognizing that bioenergy with carbon capture and storage (BECCS) may still take years to mature, this study focuses on another photosynthesis-based, negative-carbon technology that is readier to implement in China: biomass intermediate pyrolysis poly-generation (BIPP). Here we find that a BIPP system can be profitable without subsidies, while its national deployment could contribute to a 61% reduction of carbon emissions per unit of gross domestic product in 2030 compared to 2005 and result additionally in a reduction in air pollutant emissions. With 73% of national crop residues used between 2020 and 2030, the cumulative greenhouse gas (GHG) reduction could reach up to 8620 Mt CO₂-eq by 2050, contributing 13–31% of the global GHG emission reduction goal for BECCS, and nearly 4555 Mt more than that projected for BECCS alone in China. Thus, China’s BIPP deployment could have an important influence on achieving both national and global GHG emissions reduction targets.

Understanding carbon emission profile of cities from multiple perspectives is a prerequisite to design just and effective carbon reduction policies. Previous studies on CO2emissions by cities are usually confined to production or consumption-based perspective, while income-based perspective has been neglected. To fill the gap, direct emissions (a.k.a. production-based emissions), upstream emissions driven by final demand (a.k.a. consumption-based emissions) and downstream emissions enabled by primary input (a.k.a. income-based emissions) in an urban economy are comprehensively explored and compared for the first time, taking Beijing as a case. In the period of 2005_2012, Manufacture of Nonmetallic Mineral Products/Construction/Processing of Petroleum, Coking, Processing of Nuclear Fuel is identified as the key contributor to carbon emission by Beijing from the production/consumption/income-based perspective, respectively, indicating each perspective can unveil important information which the other methods fail to discover. Moreover, driving forces of CO2emissions change in Beijing are uncovered using the structural decomposition analysis (SDA) from both the demand and supply sides. Emission intensity, production input and output structure change contribute to CO2emission decrease in Beijing, which are largely offset by population, final demand/primary input level and final demand/primary input structure change, resulting in a net 3.9 Mt reduction during 2005_2012. While current policies continue to highlight end-of-pipe measures in cities, more attention should be paid to demand (e.g., encouraging low-carbon consumption) and supply side (e.g., controlling capital investment in enterprises with large income-based CO2emissions). © 2018 Elsevier Ltd