Rural energy consumption in China has increased dramatically in the last decades, and has become a significant contributor of carbon emissions. Yet there is limited data on energy consumption patterns and their evolut...Rural energy consumption in China has increased dramatically in the last decades, and has become a significant contributor of carbon emissions. Yet there is limited data on energy consumption patterns and their evolution in forest rural areas of China. In order to bridge this gap, we report the findings of field surveys in forest villages in Weichang County as a case study of rural energy consumption in northern China. We found that the residential energy consumption per household is 3313 kgce yr^-1 （kilogram standard coal equivalent per year）, with energy content of 9.7×lO7 kJ yr^-1, including 1783 kgce yr^-1 from coal, 1386 kgce yr^-1 from fuel wood, 96 kgce yr^-1 from electricity, and 49 kgce yr^-1 from LPG. Per capita consumption is 909 kgce yr^-1 and its energy content is 2.7×lO7 kJ yr^-1. Due to a total energy utilization efficiency of 24.6%, all the consumed energy can only supply about 2.4×107 kJ yr^-1 of efficient energy content. Secondly, household energy consumption is partitioned into 2614 kgce yr^-1 for heating, 616 kgce yr^-1 for cooking, and 117 kgce yr^-1 for home appliances. Thirdly, the associated carbon emissions oer household are 2556 kzC yr^-1, includinz1022 kgC yr^-1 from unutilized fuel wood （90% of the total fuel wood）. The rest of emissions come from the use of electricity （212 kgC yr^-1, coal （13Ol kgC yr^-1 and LPG （21 kgC yr^-1. Fourthly, local climate, family size and household income have strong influences on rural residential energy consumption. Changes in storage and utilization practices of fuel can lead to the lO%-30% increase in the efficiency of fuel wood use, leading to reduced energy consumption by 924 kgce yr^-1 per household （27.9% reduction） and 9Ol kgC yr^-1 of carbon emissions （35-3% reduction）.展开更多
Agriculture is a large source of carbon emissions. The cropland practices of fertilizer substitution, crop straw and conservation tillage are beneficial and help to rebuild local soil carbon stocks and reduce soil car...Agriculture is a large source of carbon emissions. The cropland practices of fertilizer substitution, crop straw and conservation tillage are beneficial and help to rebuild local soil carbon stocks and reduce soil carbon emissions, in addition to reducing the consumption of fertilizers and fossil fuels. These improved cropland practices can directly and indirectly mitigatecarbon emissions, benefiting the sustainability of croplands. For these three improved practices, we estimated carbon mitigation potentials in rice, wheat and maize croplands in China. The combined contribution of these practices to carbon mitigation was 38.8 Tg C yr-1, with fertilizer substitution, crop straw return, and conservation tillage contributing 26.6, 3.6 and 8.6 Tg C yr-1, respectively. Rice, wheat and maize croplands had potentials to mitigate 13.4, 11.9 and 15.5 Tg C yr-1, respectively, with the combined direct and indirectpotential of 33.8 and 5.0 Tg C yr-1. Because of differences in local climate and specific diets, the regional cropland carbon mitigation potentials differed greatly among provinces in China. In China, 18 provinces had a "target surplus" for which the carbon mitigation from these three practices was larger than the mitigation target set for 2020. At the national level, a net "target surplus"of 4.84 Tg C yr-1 would be attained for Chinese croplands with full implementation of the three improved practices. Regional cooperation must be developed to achieve carbon mitigation targets using such measures as carbon trading, establishing regional associations, and strengthening research programs to improve practices.展开更多
Current and past land use practices are critical in determining the distribution and size of global terrestrial carbon (C) sources and sinks. Althoughfossil fuel emissions dominate the anthropogenic perturbation of th...Current and past land use practices are critical in determining the distribution and size of global terrestrial carbon (C) sources and sinks. Althoughfossil fuel emissions dominate the anthropogenic perturbation of the global C cycle, land use still drives the largest portion of anthropogenic emissions in a number of tropical regions of Asia. The size of the emission flux owing to land use change is still the biggest uncertainty in the global C budget. The Intergovernmental Panel on Climate Change (IPCC) reported a flux term of 1.7 PgC@a-1 for 1990-1995 but more recent estimates suggest the magnitude of this source may be only of 0.96 PgC@a-1 for the 1990s. In addition, current and past land use practices are now thought to contribute to a large degree to the northern hemisphere terrestrial sink, and are the dominant driver for some regional sinks. However, mechanisms other than land use change need to be invoked in order to explain the inferred C sink in the tropics. Potential candidates are the carbon dioxide (CO2) fertilization and climate change; fertilization due to nitrogen (N) deposition is believed to be small or nil. Although the potential for managing C sinks is limited, improved land use management and new land uses such as reforestation and biomass fuel cropping, can further enhance current terrestrial C sinks. Best management practices in agriculture alone could sequester 0.4-0.8 PgC per year in soils if implemented globally. New methodologies to ensure verification and permanency of C sequestration need to be developed.展开更多
文摘Rural energy consumption in China has increased dramatically in the last decades, and has become a significant contributor of carbon emissions. Yet there is limited data on energy consumption patterns and their evolution in forest rural areas of China. In order to bridge this gap, we report the findings of field surveys in forest villages in Weichang County as a case study of rural energy consumption in northern China. We found that the residential energy consumption per household is 3313 kgce yr^-1 （kilogram standard coal equivalent per year）, with energy content of 9.7×lO7 kJ yr^-1, including 1783 kgce yr^-1 from coal, 1386 kgce yr^-1 from fuel wood, 96 kgce yr^-1 from electricity, and 49 kgce yr^-1 from LPG. Per capita consumption is 909 kgce yr^-1 and its energy content is 2.7×lO7 kJ yr^-1. Due to a total energy utilization efficiency of 24.6%, all the consumed energy can only supply about 2.4×107 kJ yr^-1 of efficient energy content. Secondly, household energy consumption is partitioned into 2614 kgce yr^-1 for heating, 616 kgce yr^-1 for cooking, and 117 kgce yr^-1 for home appliances. Thirdly, the associated carbon emissions oer household are 2556 kzC yr^-1, includinz1022 kgC yr^-1 from unutilized fuel wood （90% of the total fuel wood）. The rest of emissions come from the use of electricity （212 kgC yr^-1, coal （13Ol kgC yr^-1 and LPG （21 kgC yr^-1. Fourthly, local climate, family size and household income have strong influences on rural residential energy consumption. Changes in storage and utilization practices of fuel can lead to the lO%-30% increase in the efficiency of fuel wood use, leading to reduced energy consumption by 924 kgce yr^-1 per household （27.9% reduction） and 9Ol kgC yr^-1 of carbon emissions （35-3% reduction）.
基金supported by the National Science and Technology Major Project(2015ZX07203-005)the National Program for Support of Top-notch Young Professionals
文摘Agriculture is a large source of carbon emissions. The cropland practices of fertilizer substitution, crop straw and conservation tillage are beneficial and help to rebuild local soil carbon stocks and reduce soil carbon emissions, in addition to reducing the consumption of fertilizers and fossil fuels. These improved cropland practices can directly and indirectly mitigatecarbon emissions, benefiting the sustainability of croplands. For these three improved practices, we estimated carbon mitigation potentials in rice, wheat and maize croplands in China. The combined contribution of these practices to carbon mitigation was 38.8 Tg C yr-1, with fertilizer substitution, crop straw return, and conservation tillage contributing 26.6, 3.6 and 8.6 Tg C yr-1, respectively. Rice, wheat and maize croplands had potentials to mitigate 13.4, 11.9 and 15.5 Tg C yr-1, respectively, with the combined direct and indirectpotential of 33.8 and 5.0 Tg C yr-1. Because of differences in local climate and specific diets, the regional cropland carbon mitigation potentials differed greatly among provinces in China. In China, 18 provinces had a "target surplus" for which the carbon mitigation from these three practices was larger than the mitigation target set for 2020. At the national level, a net "target surplus"of 4.84 Tg C yr-1 would be attained for Chinese croplands with full implementation of the three improved practices. Regional cooperation must be developed to achieve carbon mitigation targets using such measures as carbon trading, establishing regional associations, and strengthening research programs to improve practices.
文摘Current and past land use practices are critical in determining the distribution and size of global terrestrial carbon (C) sources and sinks. Althoughfossil fuel emissions dominate the anthropogenic perturbation of the global C cycle, land use still drives the largest portion of anthropogenic emissions in a number of tropical regions of Asia. The size of the emission flux owing to land use change is still the biggest uncertainty in the global C budget. The Intergovernmental Panel on Climate Change (IPCC) reported a flux term of 1.7 PgC@a-1 for 1990-1995 but more recent estimates suggest the magnitude of this source may be only of 0.96 PgC@a-1 for the 1990s. In addition, current and past land use practices are now thought to contribute to a large degree to the northern hemisphere terrestrial sink, and are the dominant driver for some regional sinks. However, mechanisms other than land use change need to be invoked in order to explain the inferred C sink in the tropics. Potential candidates are the carbon dioxide (CO2) fertilization and climate change; fertilization due to nitrogen (N) deposition is believed to be small or nil. Although the potential for managing C sinks is limited, improved land use management and new land uses such as reforestation and biomass fuel cropping, can further enhance current terrestrial C sinks. Best management practices in agriculture alone could sequester 0.4-0.8 PgC per year in soils if implemented globally. New methodologies to ensure verification and permanency of C sequestration need to be developed.
