Abstract: To achieve the coordinated development of a water-energy-food system covering the Beijing-Tianjin-Hebei region under carbon neutrality, this paper constructs a three-dimensional water-energy-food-carbon security assessing model that considers reliability within individual systems, coordination between dual systems, and sustainability among multiple systems. We adopt an improved criteria importance through intercriteria correlation (CRITIC) method to assess the security level of this system in the 2000-2022 period, and examine the changes in system security caused by implementing certain carbon emission indicators. Its primary obstacle factors are identified for this region. The results indicate a rising trend in the coupling system’s security level in this period, with its average value rising from 0.354 to 0.535, while it decreased to 0.508 in 2022 thanks to the carbon neutrality policy. Since carbon neutrality implementation started in 2020, system security has been improved to a certain degree. Primary obstacle factors that affect the system’s security in this region are energy production elasticity coefficient, SO2 emission in exhaust gases, food yield fluctuation index, difference between food exports and imports, number of civilian vehicles, and proportion of hydroelectricity generation.

Key words: water-energy-food-carbon, carbon neutrality, system security, Beijing-Tianjin-Hebei region, improved CRITIC method, obstacle factors