[en] The ongoing trade war between the United States and China is having profound impacts on the global economy. As recent studies have found substantial amounts of carbon dioxide and air pollution embedded in the global supply chains, the Sino–US trade war may also affect emissions and health burdens worldwide, which remains poorly understood. Here, we estimate the potential changes in gross domestic product (GDP), anthropogenic emissions and particulate matter (PM_2.5) related premature deaths worldwide under two Sino–US trade war scenarios. We find that for the US and China, the trade war would reduce their GDP and, less significantly, emissions and mortality, suggesting that the trade war is not an effective means of environmental protection. The trade war would increase both GDP and mortality in many developing regions, because of their increased production of goods targeted in the Sino–US trade war. Surprisingly, Western Europe and Latin America and Caribbean would have higher GDP but lower emissions and mortality, an economic and environmental win-win outcome as a net result of the complex changes in the global supply chains. Neighbour regions of the US and China such as Canada, Japan and Korea would also have higher GDP but lower mortality, because of reduced atmospheric transboundary transport from the US and China overcompensating for increased local emissions of these neighbours. The complex consequences of the Sino–US trade war highlight the strong inter-regional and economic-environmental linkage in support of a global collaborative strategy to foster economic growth and environmental protection. (letter)

[en] Highlights: • CO₂ emissions from the central heating supply system in China increased from 189.04 Tg to 319.39 Tg from 2006 to 2015. • Coal-fire heating boiler plants represent the main source of emissions in China. • Regions with large central heating areas, durations and coverages always produced more CO₂ emissions. • CO₂ emissions in 2025 will be 520.97 Tg, 308.79 Tg and 191.86 Tg under the business as usual, positive and optimal scenarios. Policies associated with the central heating supply system affect the livelihoods of people in China. With the extensive consumption of energy for central heating, large quantities of CO₂ emissions are produced each year. Coal-fired heating boiler plants are the primary source of emissions; however, thermal power plants are becoming much more prevalent, and gas-fired heating boiler plants remain uncommon. This study quantified the amount of CO₂ emitted from the central heating supply system in China using a mass balance method with updated emission factors from the IPCC. Emissions increased from 189.04 Tg to 319.39 Tg between 2006 and 2015. From a spatial perspective, regions with larger central heating areas, durations and coverages produced more CO₂ emissions. The central heating method depends on the level of electric power consumption, policies and regulations, and resource reserves at the local scale. Compared with the use of only coal-fired heating boiler plants to provide central heating, using thermal power plants and gas-fired heating boiler plants reduced CO₂ emissions by 98.19 Tg in 2015 in China. A comparison of the CO₂ emissions under various central heating scenarios showed that emissions will be 520.97 Tg, 308.79 Tg and 191.86 Tg for business as usual, positive and optimal scenarios through 2025, respectively. China has acknowledged the considerable potential for reducing central heating and will make efforts to pursue improved heating strategies in the future.

[en] Highlights: • Spatiotemporal changes of central heating CO₂ emissions at city level are shown. • A high-resolution gridded inventory of heating-related CO₂ emissions is built. • The satellite nighttime light data is used to downscale the city level emissions. • Differences in CO₂ emissions between urban and non-urban areas are discussed. -- Abstract: Energy consumption from central heating has rapidly increased in the cities of the North China Plain (NCP). The increasing use of natural gas in the central heating supply system may have altered the spatial and temporal patterns of CO₂ emissions from central heating, yet the quantitative impacts are poorly understood. Here we detect the spatio-temporal dynamics of CO₂ emissions of central heating from 2012 to 2016 at the prefectural-city level in the NCP region, by using the satellite NPP-VIIRS nighttime light data and a panel regression model to estimate CO₂ emissions on a 5 × 5 km² grid. We find that despite a slight decrease (2%) in 2014 under the “Natural Gas Utilization Policy”, CO₂ emissions continued to grow. Between 2012 and 2016, CO₂ emissions from central heating in the NCP increased from 106 to 121 Tg, although CO₂ emissions declined by 12% in Beijing due to the increasing contribution of natural gas boilers. The gridded CO₂ emissions map shows that over 2012–2016 coal burning is the main driving force of CO₂ emissions in both urban and non-urban regions, despite the increasing fraction of gas-based heating. Our results contribute to city-level policymaking on carbon reduction and climate change mitigation. The high-resolution gridded CO₂ emissions can also be applied in physical models to facilitate carbon cycle studies.