Grassland fires results in carbon emissions,which directly affects the carbon cycle of ecosystems and the carbon balance.The grassland area of Inner Mongolia accounts for 22%of the total grassland area in China,and ma...Grassland fires results in carbon emissions,which directly affects the carbon cycle of ecosystems and the carbon balance.The grassland area of Inner Mongolia accounts for 22%of the total grassland area in China,and many fires occur in the area every year.However,there are few models for estimation of carbon emissions from grassland fires.Accurate estimation of direct carbon emissions from grassland fires is critical to quantifying the contribution of grassland fires to the regional balance of atmospheric carbon.In this study,the regression equations for aboveground biomass(AGB)of grassland in growing season and MODIS NDVI(Normalized Difference Vegetation Index)were established through field experiments,then AGB during Nov.–Apr.were retrieved based on that in Oct.and decline rate,finally surface fuel load was obtained for whole year.Based on controlled combustion experiments of different grassland types in Inner Mongolia,the carbon emission rate of grassland fires for each grassland type were determined,then carbon emission was estimated using proposed method and carbon emission rate.Results revealed that annual average surface fuel load of grasslands in Inner Mongolia during 2000–2016 was approximately 1.1978×1012 kg.The total area of grassland which was burned in the Inner Mongolia region over the 17-year period was 5298.75 km2,with the annual average area of 311.69 km2.The spatial distribution of grassland surface fuel loads is characterized by decreasing from northeast to southwest in Inner Mongolia.The total carbon emissions from grassland fires amounted to 2.24×107 kg with an annual average of 1.32×106 for the study area.The areas with most carbon emissions were mainly concentrated in Old Barag Banner and New Barag Right Banner and on the right side of the Oroqin Autonomous Banner.The spatial characteristics of carbon emission depend on the location of grassland fire,mainly in the northeast of Inner Mongolia include Hulunbuir City,Hinggan League,Xilin Gol League and Ulanqab City.The area and spatial location of grassland fires can directly affect the total amount and spatial distribution of carbon emissions.This study provides a reference for estimating carbon emissions from steppe fires.The model and framework for estimation of carbon emissions from grassland fires established can provide a reference value for estimation of carbon emissions from grassland fires in other regions.展开更多
Accurately estimating carbon emissions is crucial under the Paris Agreement,especially for thermal power plants,the largest source of fossil fuel emissions.While traditional methods are validated by satellite remote s...Accurately estimating carbon emissions is crucial under the Paris Agreement,especially for thermal power plants,the largest source of fossil fuel emissions.While traditional methods are validated by satellite remote sensing,the effectiveness of satellites like the Orbiting Carbon Observatory(OCO)for national-level carbon inventories remains debated.This study evaluates satellite capabilities in monitoring emissions from thermal power plants,considering frequency,column-averaged dry-air mole fraction of CO_(2)(XCO_(2))precision,and spatial resolution.A correction strategy is proposed for global carbon stocktake using satellite data.The study reveals that the OCO-2 v11.1 and OCO-3 v10 satellites,with their approximate 1 part per million(ppm)XCO_(2) precision,substantially underestimate total U.S.power plant emissions by 70%(±12%)due to their inability to detect emissions from smaller facilities.Improving precision to 0.5 ppm can narrow this gap to 52%(±17%).Further reductions in this discrepancy can be achieved by enhancing monitoring frequency,XCO_(2) precision,and spatial resolution.Specifically,with a precision of 0.7 ppm,a spatial resolution of 0.5 km,and daily monitoring,the error can be decreased to less than 20%.A parallel analysis of the planned Copernicus Anthropogenic CO_(2) Monitoring Mission estimates that it could detect 52% of total U.S.power plant emissions,while TanSat-2 Global is projected to detect 44%.The findings highlight current limitations in satellite-based global carbon stocktake but indicate future potential improvements with higher spatiotemporal resolution and precision in upcoming satellite missions.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 4176110141771450+2 种基金41871330)National Natural Science Foundation of Inner Mongolia (No. 2017MS0409)Fundamental Research Funds for the Central Universities (No. 2412019BJ001)
文摘Grassland fires results in carbon emissions,which directly affects the carbon cycle of ecosystems and the carbon balance.The grassland area of Inner Mongolia accounts for 22%of the total grassland area in China,and many fires occur in the area every year.However,there are few models for estimation of carbon emissions from grassland fires.Accurate estimation of direct carbon emissions from grassland fires is critical to quantifying the contribution of grassland fires to the regional balance of atmospheric carbon.In this study,the regression equations for aboveground biomass(AGB)of grassland in growing season and MODIS NDVI(Normalized Difference Vegetation Index)were established through field experiments,then AGB during Nov.–Apr.were retrieved based on that in Oct.and decline rate,finally surface fuel load was obtained for whole year.Based on controlled combustion experiments of different grassland types in Inner Mongolia,the carbon emission rate of grassland fires for each grassland type were determined,then carbon emission was estimated using proposed method and carbon emission rate.Results revealed that annual average surface fuel load of grasslands in Inner Mongolia during 2000–2016 was approximately 1.1978×1012 kg.The total area of grassland which was burned in the Inner Mongolia region over the 17-year period was 5298.75 km2,with the annual average area of 311.69 km2.The spatial distribution of grassland surface fuel loads is characterized by decreasing from northeast to southwest in Inner Mongolia.The total carbon emissions from grassland fires amounted to 2.24×107 kg with an annual average of 1.32×106 for the study area.The areas with most carbon emissions were mainly concentrated in Old Barag Banner and New Barag Right Banner and on the right side of the Oroqin Autonomous Banner.The spatial characteristics of carbon emission depend on the location of grassland fire,mainly in the northeast of Inner Mongolia include Hulunbuir City,Hinggan League,Xilin Gol League and Ulanqab City.The area and spatial location of grassland fires can directly affect the total amount and spatial distribution of carbon emissions.This study provides a reference for estimating carbon emissions from steppe fires.The model and framework for estimation of carbon emissions from grassland fires established can provide a reference value for estimation of carbon emissions from grassland fires in other regions.
基金supported by the National Key Research and Development Program of China(2022YFB3904801).
文摘Accurately estimating carbon emissions is crucial under the Paris Agreement,especially for thermal power plants,the largest source of fossil fuel emissions.While traditional methods are validated by satellite remote sensing,the effectiveness of satellites like the Orbiting Carbon Observatory(OCO)for national-level carbon inventories remains debated.This study evaluates satellite capabilities in monitoring emissions from thermal power plants,considering frequency,column-averaged dry-air mole fraction of CO_(2)(XCO_(2))precision,and spatial resolution.A correction strategy is proposed for global carbon stocktake using satellite data.The study reveals that the OCO-2 v11.1 and OCO-3 v10 satellites,with their approximate 1 part per million(ppm)XCO_(2) precision,substantially underestimate total U.S.power plant emissions by 70%(±12%)due to their inability to detect emissions from smaller facilities.Improving precision to 0.5 ppm can narrow this gap to 52%(±17%).Further reductions in this discrepancy can be achieved by enhancing monitoring frequency,XCO_(2) precision,and spatial resolution.Specifically,with a precision of 0.7 ppm,a spatial resolution of 0.5 km,and daily monitoring,the error can be decreased to less than 20%.A parallel analysis of the planned Copernicus Anthropogenic CO_(2) Monitoring Mission estimates that it could detect 52% of total U.S.power plant emissions,while TanSat-2 Global is projected to detect 44%.The findings highlight current limitations in satellite-based global carbon stocktake but indicate future potential improvements with higher spatiotemporal resolution and precision in upcoming satellite missions.
