In recent years,researchers have devoted considerable attention to identifying the causes of urban environmental pollution.To determine whether migrant populations significantly affect urban environments,we examined t...In recent years,researchers have devoted considerable attention to identifying the causes of urban environmental pollution.To determine whether migrant populations significantly affect urban environments,we examined the relationship between urban environmental pollutant emissions and migrant populations at the prefectural level using data obtained for 90 Chinese cities evidencing net in-migration.By dividing the permanent populations of these cities into natives and migrants in relation to the population structure,we constructed an improved Stochastic Impacts by Regression on Population,Affluence and Technology model(STIRPAT)that included not only environmental pollutant emission variables but also variables on the cities’attributes.We subsequently conducted detailed analyses of the results of the models to assess the impacts of natives and migrants on environmental pollutant emissions.The main findings of our study were as follows:1)Migrant populations have significant impacts on environmental emissions both in terms of their size and concentration.Specifically,migrant populations have negative impacts on Air Quality Index(AQI)as well as PM2.5 emissions and positive impacts on emissions of NO2 and CO2.2)The impacts of migrant populations on urban environmental pollutant emissions were 8 to 30 times weaker than that of local populations.3)Urban environmental pollutant emissions in different cities differ significantly according to variations in the industrial structures,public transportation facilities,and population densities.展开更多
In the context of the era of carbon peaking and carbon neutrality,clarifying the emission patterns of non-CO_(2)Greenhouse Gas(GHG)from agricultural sources is of practical significance to China’s implementation of g...In the context of the era of carbon peaking and carbon neutrality,clarifying the emission patterns of non-CO_(2)Greenhouse Gas(GHG)from agricultural sources is of practical significance to China’s implementation of greenhouse gas emission reduction policies.The Intergovernmental Panel on Climate Change(IPCC)coefficient method was used to calculate non-CO_(2)GHG emissions from agricultural sources in 122 counties in Hunan Province,China,from 2010 to 2020,and the spatiotemporal evolution characteristics of emission intensity were analyzed.The Stochastic Impacts by Regression on Population,Affluence,and Technology(STRIPAT)model forecasted the prospective evolution of non-CO_(2)GHG emissions from agricultural sources at the county level under various scenarios from 2030 to 2050.The results demonstrated a general decline in non-CO_(2)GHG emissions from agricultural sources within the study area,with 75.41%of counties exhibiting a reduction in emissions.Geographically,emissions were higher in the Dongting Lake area and central Hengyang.The emission intensity per unit of agricultural added value and the intensity per unit of agricultural land area showed an overall downward trend.Spatially,the emission intensity per unit of farmland area in a few counties(cities,districts)in southern Hunan was still relatively high.By forecasting the non-CO_(2)GHG emissions from agricultural sources,the majority of counties(cities and districts)demonstrated a gradual decline in emissions,suggesting that agricultural production had the potential to reduce emissions in the future,while also facing certain pressure to reduce emissions.It is recommended that Hunan Province formulate agricultural carbon emission reduction policies that take regional development differences into account.This would provide a reference for future agricultural carbon emission reduction research in the whole country.展开更多
基金Under the auspices of Shanxi Scholarship Council of China(No.2017-003)
文摘In recent years,researchers have devoted considerable attention to identifying the causes of urban environmental pollution.To determine whether migrant populations significantly affect urban environments,we examined the relationship between urban environmental pollutant emissions and migrant populations at the prefectural level using data obtained for 90 Chinese cities evidencing net in-migration.By dividing the permanent populations of these cities into natives and migrants in relation to the population structure,we constructed an improved Stochastic Impacts by Regression on Population,Affluence and Technology model(STIRPAT)that included not only environmental pollutant emission variables but also variables on the cities’attributes.We subsequently conducted detailed analyses of the results of the models to assess the impacts of natives and migrants on environmental pollutant emissions.The main findings of our study were as follows:1)Migrant populations have significant impacts on environmental emissions both in terms of their size and concentration.Specifically,migrant populations have negative impacts on Air Quality Index(AQI)as well as PM2.5 emissions and positive impacts on emissions of NO2 and CO2.2)The impacts of migrant populations on urban environmental pollutant emissions were 8 to 30 times weaker than that of local populations.3)Urban environmental pollutant emissions in different cities differ significantly according to variations in the industrial structures,public transportation facilities,and population densities.
基金Under the auspices of the National Natural Science Foundation of China(No.42471241,41971219,41571168)Hunan Provincial Natural Science Foundation(No.2020JJ4372)。
文摘In the context of the era of carbon peaking and carbon neutrality,clarifying the emission patterns of non-CO_(2)Greenhouse Gas(GHG)from agricultural sources is of practical significance to China’s implementation of greenhouse gas emission reduction policies.The Intergovernmental Panel on Climate Change(IPCC)coefficient method was used to calculate non-CO_(2)GHG emissions from agricultural sources in 122 counties in Hunan Province,China,from 2010 to 2020,and the spatiotemporal evolution characteristics of emission intensity were analyzed.The Stochastic Impacts by Regression on Population,Affluence,and Technology(STRIPAT)model forecasted the prospective evolution of non-CO_(2)GHG emissions from agricultural sources at the county level under various scenarios from 2030 to 2050.The results demonstrated a general decline in non-CO_(2)GHG emissions from agricultural sources within the study area,with 75.41%of counties exhibiting a reduction in emissions.Geographically,emissions were higher in the Dongting Lake area and central Hengyang.The emission intensity per unit of agricultural added value and the intensity per unit of agricultural land area showed an overall downward trend.Spatially,the emission intensity per unit of farmland area in a few counties(cities,districts)in southern Hunan was still relatively high.By forecasting the non-CO_(2)GHG emissions from agricultural sources,the majority of counties(cities and districts)demonstrated a gradual decline in emissions,suggesting that agricultural production had the potential to reduce emissions in the future,while also facing certain pressure to reduce emissions.It is recommended that Hunan Province formulate agricultural carbon emission reduction policies that take regional development differences into account.This would provide a reference for future agricultural carbon emission reduction research in the whole country.
