Spatial and temporal analysis of carbon sources and sinks through land use/cover changes in the Beijing-Tianjin-Hebei urban agglomeration region

Global warming caused by carbon emissions have been recognized as a threat to social health and ecological security. Through matching the relationship between land use types and carbon emissions, based on land use and socio-economic data, this paper uses the emission factor method proposed by IPCC to investigate carbon sources and sinks, as well as validation through land use/cover changes analysis in the Beijing-Tianjin-Hebei (BTH) urban agglomeration region from 1990 to 2015. Our results demonstrated that carbon sources have increased by almost threefold (23983.7 x 10(4)t) from 1990 to 2015 while carbon sinks have declined rapidly to one-eighth of the original amount (84 x 10(4)t) since 1995. Meanwhile, the built-up areas accounted for 88% of the total carbon emission. In the BTH region for 2015, the average carbon source intensity was 79 times greater than the average carbon sink intensity, indicating that the BTH region had serious carbon deficit and requires a significant reduction in carbon emissions. Furthermore, net carbon emissions in the BTH region increased by about 173% during the past 26 years, representing a 3.9% average annual increase. Our findings demonstrate the response of land use types to carbon balance in the BTH region are comparable at the national and regional level. In addition, they provide guidelines for land-use management, especially in terms of the synergetic development of the BTH region.