Variation of global fossil-energy carbon footprints based on regional net primary productivity and the gravity model

This study builds an evaluation model of national fossil-energy carbon footprints based on regional average net primary productivity calculated by weighted method and evaluates the carbon footprint of fossil fuel energy consist of oil, natural gas and coal for 64 major carbon emitters, on the basis of regional net primary productivity data of various land types and national fossil fuel energy consumption data. The variation of national total and per capita fossil-energy carbon footprints is analyzed and compared, and global overall changes of nonuniform distribution of national fossil-energy carbon footprints are analyzed via application of the gravity model, which provides a methodology to present the trend of overall changes of a certain attribute in the non-uniform geographical distribution problem. The target years for calculation and analysis of fossil-energy carbon footprints are from 1997 to 2016. The results show that the majority of developed countries present decrease while most of developing countries present increase both in the total and per capita fossil-energy carbon footprint during the twenty years, and serious polarization is found in the rankings of the twenty-year average of both total and per capita fossil-energy carbon footprint, with the maximum value being respectively 486 and 583 times of the minimum value. And both the global total and per capita fossil-energy carbon footprint barycenter, which are introduced according to the gravity model, generally move toward southeast during 1997–2016 with different change range, proving an uneven growth of the fossil-energy carbon footprints worldwide. And the global distribution of fossil-energy carbon footprints has become more nonuniform in value. Several policy recommendations are proposed on the aspects of carbon emission reduction and promotion of carbon absorption from productive lands, and all the countries are emphasized with equal responsibility of carbon footprint reduction.