Predicting national sustainability: The convergence of energetic, economic and environmental realities

Cross-City Convergence in Urban Green Space Coverage in China

Cross-city convergence in green space coverage could contribute to our understanding of the law of motion of distribution dynamics of environmental sustainability across cities and provide crucial information for designing policies regarding complex processes relating to human–environment interactions in an urban system. The relationship between socioeconomic factors and green space coverage has been widely discussed, but research on the distribution dynamics of green space coverage across cities is limited. This paper explored the pattern of convergence in green space coverage of a group of 285 Chinese cities over the period of 2002–2012 by using hybrid approaches, including the nonparametric estimation technique, unconditional β-convergence model, and conditional β-convergence model. The results indicated that the green space coverage level in most cities has been substantially improved; the spatial disparity across Chinese cities has shrunk, and the level of green space coverage has converged to 104% of the average level. The β-convergence estimation results demonstrate the existence of unconditional and conditional convergence in green space coverage among Chinese cities, which indicates that cities with a low initial level of green space coverage grow faster than those with an initial high level. Faster sprawling, more compact and wealthier cities are likely to converge to a higher level of green space coverage. Expansion of the population and spatial scale of cities contributes to increasing green space coverage, sprawling of built-up area leads to a decrease of the green space coverage, and economic growth has little impact on green space coverage.

A thermodynamic geography: night-time satellite imagery as a proxy measure of emergy

Night-time satellite imagery enables the measurement, visualization, and mapping of energy consumption in an area. In this paper, an index of the "sum of lights" as observed by night-time satellite imagery within national boundaries is compared with the emergy of the nations. Emergy is a measure of the solar energy equivalent used, directly or indirectly, to support the processes that characterize the economic activity in a country. Emergy has renewable and non-renewable components. Our results show that the non-renewable component of national emergy use is positively correlated with night-time satellite imagery. This relationship can be used to produce emergy density maps which enable the incorporation of spatially explicit representations of emergy in geographic information systems. The region of Abruzzo (Italy) is used to demonstrate this relationship as a spatially disaggregate case.

Emergy accounting for regional studies: case study of Canada and its provinces

Sustainable regional management (development) requires an understanding of interactions between the social, economic, and ecological systems within the boundaries of a region. In this paper, application of emergy (an environmental accounting method) for regional planning is discussed through a case study. Emergy (spelled with an "m") methodology is an environmental accounting technique that evaluates the energy system for the thermodynamics of an open system. Major renewable and non-renewable resource fluxes to a region, including energy, matter, human activities, and money can be converted to emergy by using corresponding transformity functions. As a case study, this paper discusses the emergy accounting of Canada and its provinces with various emergy-based indicators. Moreover, emergy maps were generated in a form of emergy geography. These maps are multi-dimensional illustrations that show resource consumption, emergy per person, and emergy density across Canada under two parameters: (1) the quantities of resources consumed and (2) the location of consumption. Emergy analysis also highlights concentrations of renewable and natural resources in Canada and distinguishes the provinces with the highest resource consumption. Analysis of emergy indicator for Canadian provinces shows that Alberta with the highest EYR (7.35) provides energy to the economy of Canada. However, ELR value of Alberta (8.5) indicates that the province's current economic approach is not sustainable as it relies mainly on non-renewable emergy inputs (mainly from fossil fuels). ELR of British Columbia and Manitoba indicates that these two provinces created a firm balance between emergy use of renewable and non-renewable resources. The characterizations of regions provided in this paper can be used for future land planning and management both in federal and provincial levels.