Total-factor energy efficiency of ten major global energy-consuming countries

Improving energy efficiency is regarded as a key path to tackling global warming and achieving the Sustainable Development Goals(SDGs).In 2020,the energy consumption of the world's ten major energy-consuming countries accounted for 66.8%of the global total.This paper applied data envelopment analysis(DEA)to calculate these ten major energyconsuming countries'total-factor energy efficiency(TFEE)at national and sectoral levels from 2001-2020,and explored the infuencing factors of total-factor energy efficiency with the Tobit regression model.The results showed significant difference in the ten countries'energy efficiency.The United States and Germany topped the list for total-factor energy efficiency,while China and India were at the bottom.Meanwhile,the energy efficiency of the industrial subsector has increased significantly over the past two decades,while that of the other subsectors has been relatively fat.The industrial structure upgrading,per capita GDP,energy consumption structure,and foreign direct investment had significant impacts on energy efficiency with national heterogeneity.Energy consumption structure and GDP per capita were determinative factors of energy efficiency.

Ecology of industrial pollution in China

Industrial development has brought China both opportunities and challenges since the reform and opening up in 1978.Spatial and temporal analysis showed that rapid industrialization has made eastern China under a more serious pollution stress.The most serious effects of industrial pollution were reflected in aquatic and soil ecosystem degradation,and damage can be observed from species,population,and community to ecosystem level.Public consciousness about contaminated sites rose from 2004 leading to greater efforts in ecological remediation,monitoring,and risk governance.Considerable efforts are still needed in expanding the extent and breadth of monitoring to explore where the greatest ecological risks lie and how to control them.Ecology of industrial pollution has become a popular discipline in China and will be further developed to help achieve the Sustainable Development Goals.Future research for a better ecological risk management should be focused on multi-media transfer and effects of mixed pollutants,mechanisms for clean energy and material flow,and integration of ecological risk with human health risk.

Driving mechanisms for decoupling CO_(2)emissions from economic development in the ten largest emission countries

The significant contribution to CO_(2)emissions includes historically cumulative emissions in the United States,Russia,Japan,South Korea,and Germany,as well as the current increase in emerging economies,such as China,India,Iran,Indonesia,and Saudi Arabia,which contribute 68%of global emissions.Therefore,it is important to measure changes in CO_(2)emissions and driving mechanisms in these countries.This study used the LMDI and STIRPAT model to explore driving mechanisms for decoupling CO_(2)emissions from economic growth in the 10 largest emission countries based on the World Bank and International Energy Agency databases.The results showed that CO_(2)emissions have tripled in these countries over the last 55 years,driven primarily by economic growth(+170%)and population growth(+41%),whereas a decline in energy intensity(-87%)and carbon intensity(-24%)slowed the growth of CO_(2)emissions over most of the period.In China,the United States,and India,significant increases in CO_(2)emissions were associated withpopulation and economic growth.Intensity effects were prominent in emission reductions in China,the United States,Germany,Japan,and Russia.Overall,the developed countries except for South Korea showed strong decoupling relationships,whereas six developing countries were weak in decoupling.