Ecological sustainability assessment of the carbon footprint in Fujian Province, southeast China

China's rapid economic development has initiated the deterioration of its ecological environment, posing a threat to the sustainable development of human society. As a result, an assessment of regional sustainability is critical. This paper researches China's most forested province, Fujian Province, as the study area. We proposed a grid-based approach to assess the regional carbon footprint in accordance with the Intergovernmental Panel on Climate Change's (IPCC) carbon emission guidelines. Our method of assessment also introduced carbon emission indicators with our improved and published Net Primary Production (NPP) based on process simulation. The carbon footprint in Fujian Province from 2005-2017 was calculated and examined from a spatiotemporal perspective. Ecological indicators were used in the sustainability assessment. The research draws the following conclusions: 1) the carbon footprint in the eastern regions of Fujian Province was higher due to rapid economic development; 2) that of the western regions was lower; 3) an uptrend in the carbon footprint of Fujian Province was observed. All five ecological indicators based on carbon emissions and economic and social data showed an ecologically unsustainable trend over 13 years in the research area due to unsustainable economic development. Therefore, it is urgent to balance the relationship between economic development and environmental protection. Our research provides scientific references for achieving ecological civilization and sustainability in a similar region.