Spatio-temporal evolution characteristics of carbon emissions in Beijing-Tianjin-Hebei urban agglomeration derived from integrated data of DMSP-OLS and NPP-VIIRS

Beijing-Tianjin-Hebei urban agglomeration(BTHUA) was taken as the study area to explore the spatio-temporal evolution characteristics of carbon emissions at the city level and above. By fitting the optimal model, NPP-VIIRS data was transformed into DMSP-OLS scale nighttime light data, and the long-time series nightlight image set of BTHUA from 2005 to 2019 was obtained. Combined with the provincial energy consumption statistical and carbon emission data, a municipal scale carbon emission estimation model at the city level and above in BTHUA was constructed. The spatial distribution of carbon emissions in BTHUA was simulated, and the temporal and spatial evolution characteristics of carbon emissions were explored in combination with the tendency value method. The results showed that: From 2005 to 2019, the correlation between nighttime light data and carbon emissions of energy consumption in BTHUA was high, and the significance test of 1% was passed. From 2005 to 2019, the carbon emissions of 13 cities in BTHUA were basically increasing gradually. Overall, the growth rate of carbon emissions in BTHUA was relatively slow from 2005 to 2019. Among them, Beijing-Tianjin-Tangshan area had a rapid growth rate. In 2019, many of the 13 cities in BTHUA reduced their carbon emissions per unit of GDP by more than 40% compared with that in 2005. The research showed that the nighttime light data could be used to estimate the carbon emissions of BTHUA, and the carbon emissions in Beijing-Tianjin-Tangshan area were high and the growth rate was fast, so it should be regarded as a key carbon emission reduction area.