The concept of environmental sustainability aims to achieve economic development while achieving a sustainable environment. The inverted U-shape relationship between economic growth and environmental quality, also called Environmental Kuznets Curve (EKC), describes the correlation between economic growth and carbon emissions. This study assesses the role of agriculture and energy-related variables while evaluating the EKC threshold in 54 African economies, and income groups, according to World Bank categorization, including low income, lower-middle, upper-middle, and high-income in Africa. With 1990–2015 panel data, the results are estimated using panel cointegration, Fully Modified Ordinary Least Square (FMOLS), and granger causality tests. The results are: (1) The study validated the EKC hypothesis in the low-income, lower-, and upper-middle-income economies. However, there is no evidence of EKC in the full African and high-income panels. Furthermore, the turning points of EKC in the income group are meagerly low, showing that Africa could be turning on EKC at lower income levels. (2) The correlation between agriculture with CO₂ is found positive in the high-income economy. However, agriculture has a mitigation effect on emissions in the lower-middle-income and low-income economies, and the full sample. Also, renewable energy is negatively correlated with emissions in Africa and the high-income economy. In contrast, non-renewable energy exerts a positive effect on emissions in all income groups except the low-income economies.

The microgrid trading market can effectively solve the problem of in-situ consumption of distributed energy and reduce the impact of distributed generation (DG) on the grid. However, the traditional microgrid trading model has some shortcomings, such as high operation cost and poor security. Therefore, in this paper, a microgrid market trading model was developed using consortium blockchain technology and Nash game equilibrium theory. Firstly, blockchain container is used to authenticate the users who want to participate in the transaction. Then, the pricing system collects and integrates transaction requests submitted by users, then formulates transaction pricing strategy of microgrid using Nash equilibrium theory. Finally, the price, trading volume, and user information are submitted to the blockchain container for transaction matching to achieve the transaction. After the transaction is completed, its related information is recorded in the hyperledger and the dispatch system is called. The scene simulation was implemented on Fabric 1.1 platform and the results analyzed. Results show that the trading model proposed in this paper greatly reduces the cost of electricity purchase and improves the benefits of electricity sales. Besides, the model is far more capable of handling transactions than the models based on Bitcoin and Ethereum.

The steel industry, which relies heavily on primary energy, is one of the industries with the highest CO₂ emissions in China. It is urgent for the industry to identify ways to embark on the path to “green steel”. Hydrogen metallurgy technology uses hydrogen as a reducing agent, and its use is an important way to reduce CO₂ emissions from long-term steelmaking and ensure the green and sustainable development of the steel industry. Previous research has demonstrated the feasibility and emission reduction effects of hydrogen metallurgy technology; however, further research is needed to dynamically analyze the overall impact of the large-scale development of hydrogen metallurgy technology on future CO₂ emissions from the steel industry. This article selects the integrated MARKAL-EFOM system (TIMES) model as its analysis model, constructs a China steel industry hydrogen metallurgy model (TIMES-CSHM), and analyzes the resulting impact of hydrogen metallurgy technology on CO₂ emissions. The results indicate that in the business-as-usual scenario (BAU scenario), applying hydrogen metallurgy technology in the period from 2020 to 2050 is expected to reduce emissions by 203 million tons, and make an average 39.85% contribution to reducing the steel industry’s CO₂ emissions. In the carbon emission reduction scenario, applying hydrogen metallurgy technology in the period from 2020 to 2050 is expected to reduce emissions by 353 million tons, contributing an average of 41.32% to steel industry CO₂ reduction. This study provides an assessment of how hydrogen metallurgy can reduce CO₂ emissions in the steel industry, and also provides a reference for the development of hydrogen metallurgy technology.