Testing environmental Kuznets curve hypothesis: The role of renewable and non-renewable energy consumption and trade in OECD countries

This paper investigates the causal relationships between per capita CO₂ emissions, gross domestic product (GDP), renewable and non-renewable energy consumption, and international trade for a panel of 25 OECD countries over the period 1980–2010. Short-run Granger causality tests show the existence of bidirectional causality between: renewable energy consumption and imports, renewable and non-renewable energy consumption, non-renewable energy and trade (exports or imports); and unidirectional causality running from: exports to renewable energy, trade to CO₂ emissions, output to renewable energy. There are also long-run bidirectional causalities between all our considered variables. Our long-run fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS) estimates show that the inverted U-shaped environmental Kuznets curve (EKC) hypothesis is verified for this sample of OECD countries. They also show that increasing non-renewable energy increases CO₂ emissions. Interestingly, increasing trade or renewable energy reduces CO₂ emissions. According to these results, more trade and more use of renewable energy are efficient strategies to combat global warming in these countries.     

CO2, economic growth,and energy consumption in China's provinces: Investigating the spatiotemporal and econometric characteristics of China's CO2 emissions

This study addresses the spatiotemporal variations at play in China's CO₂ emissions, based on an estimation of emission levels in the period 1995–2012 and an provincial analysis of the relationship of CO₂ emissions to economic growth and energy consumption. Using a series of econometric models and data on the combustion of fossil fuels and cement manufacturing, the study first estimated CO₂ emission levels during the study period, exploring their spatiotemporal pattern. The results indicate that both China's total and its per capita CO₂ emissions have increased significantly over the study period, with both measures evidencing a similar evolution (albeit one that is characterized by noticeable regional discrepancies at the provincial level and which displays properties of convergence). From a geographical perspective, we found both total and per capita CO₂ emissionsto be higher in China's eastern region than in the country's central and western regions. Panel data analysis was subsequently undertaken in order to quantify the dynamic casual relationship between economic growth, energy consumption, and CO₂ emissions. The empirical results indicated that the variables were in fact cointegrated and exhibited a long-run positive relationship. The results of further Granger causality tests indicated the existence of a bidirectional positive causality between economic growth and energy consumption, as well as between energy consumption and CO₂ emissions, and a unidirectional positive causality running from economic growth to CO₂ emissions. The findings of this study suggest that China is, in the long run, dependent on carbon energy consumption for its rapid economic growth, a dependency which is the cause of considerable increases in CO₂ emissions. China should therefore make greater efforts to develop low-carbon technologies and renewable energy, and improve energy efficiency in order to reduce emissions and achieve green economic growth.     

Does energy intensity contribute to CO2 emissions? A trivariate analysis in selected African countries

The present study investigates the dynamic relationship between energy intensity and CO₂ emissions by incorporating economic growth in environment CO₂ emissions function using data of Sub Saharan African countries. For this purpose, we applied panel cointegration to examine the long run relationship between the series. We employed the VECM Granger causality to test the direction of causality amid the variables.At panel level, our results validate the existence of cointegration among the series. The long run panel results show that energy intensity has positive and statistically significant impact on CO₂ emissions. There is also positive and negative link of non-linear and linear terms of real GDP per capita with CO₂ emissions supporting the presence of environmental Kuznets curve (EKC). The causality analysis reveals the bidirectional causality between economic growth and CO₂ emissions while energy intensity Granger causes economic growth and hence CO₂ emissions, while across the individual countries, the results differ. This paper opens up new insights for policy makers to design comprehensive economic, energy and environmental policy for sustainable long run economic growth.     

The index of sustainable economic welfare in the energy-growth nexus for American countries

Our paper is an empirical study on the comparison between the conventional energy- growth nexus and the energy-ISEW (Index for Sustainable Economic Welfare) growth nexus. We use a sample of American countries in a multivariate panel framework for a data span from 1990 to 2013, with variables such as labor, capital, carbon emissions, energy use, renewable energy, rents and trade. Results from this paper are critical for governments and institutional investors who are nowadays concerned with sustainable economic growth and welfare and not only the short-sighted GDP growth. An additional contribution of this paper is the calculation of the ISEW index for American countries, based on data availability.     

空间互动视角下CO2排放驱动因素及溢出效应——基于全球98个国家的数据分析

全球气候变暖已成为21世纪威胁人类可持续发展的严峻挑战,减少CO₂排放是抑制气候变暖的重要路径。从全球碳减排的宏观视角出发,以98个国家为研究对象,基于总商品贸易和化石能源贸易的引力模型构建两种空间互动关系,利用扩展后的S-STIRPAT模型对2000、2005、2010年和2014年人均CO₂排放的驱动机制和空间溢出效应展开实证分析,并基于发展差异视角进一步探究发达和欠发达国家CO₂排放驱动机制异同。研究结果表明：（1）2000、2005、2010年和2014年人均CO₂排放溢出效应呈增强态势。（2）城市化水平、人均GDP、能源强度对人均CO₂排放产生显著正向影响,可再生能源使用率对人均CO₂排放产生显著负向影响。（3）发展差异视角下,城市化水平、人均GDP和能源强度对欠发达国家影响更大,可再生能源使用率对发达国家影响更为显著。根据研究结果建议加强发达国家和欠发达国家低碳技术交流与合作,同时积极调整能源结构以减少CO₂排放。     

Do nuclear and renewable energy improve the environment? Empirical evidence from the United States

The central focus of this article is to assess the dynamic effects of nuclear and renewable energy consumption on CO₂ emissions, for a given level of income and energy consumption. We apply an autoregressive distributed lag (ARDL) approach to cointegration to U.S. data from 1960 to 2010. We find that nuclear energy consumption indeed reduces CO₂ emissions in both the short- and long-run, while renewable energy consumption does only in the short-run. We also find that income increases CO₂ emissions in the long-run after showing the environmental Kuznets curve (EKC) initially in the short-run. Finally, energy consumption is found to have a negative impact on reducing CO₂ emissions in the short- and long-run.     

Economic growth,electricity consumption,urbanization and environmental degradation relationship in United Arab Emirates

The present study explores the relationship between economic growth, electricity consumption, urbanization and environmental degradation in case of United Arab Emirates (UAE). The study covers the quarter frequency data over the period of 1975–2011. We have applied the ARDL bounds testing approach to examine the long run relationship between the variables in the presence of structural breaks. The VECM Granger causality is applied to investigate the direction of causal relationship between the variables. Our empirical exercise reported the existence of cointegration among the series. Further, we found an inverted U-shaped relationship between economic growth and CO₂ emissions i.e. economic growth raises energy emissions initially and declines it after a threshold point of income per capita (EKC exists). Electricity consumption declines CO₂ emissions. The relationship between urbanization and CO₂ emissions is positive. Exports seem to improve the environmental quality by lowering CO₂ emissions. The causality analysis validates the feedback effect between CO₂ emissions and electricity consumption. Economic growth and urbanization Granger cause CO₂ emissions.     

Change in cereal production caused by climate change in Malaysia

This study attempts to estimate the effects of climate change variables, such as average temperature, CO₂ emissions and average rainfall, on cereal production in Malaysia from 1969 to 2018. After preliminary tests on time series data, we employed a novel autoregressive distributed lag (ARDL) method known as the dynamic ARDL simulations technique. The results showed that a long-run co-integration relationship exists between cereal production and climatic and non-climatic factors. All climate variables have a negative impact on cereal yield, while energy consumption and cultivated land have a positive effect on cereal yield in the short- and long-run. Granger causality analyses also showed that a unidirectional causality link exists between rainfall and temperature with cereal production and between CO₂ emissions and cereal production. Energy consumption, as a proxy for technology, has a one-way Granger cause with cereal production. The results of the dynamic ARDL simulations suggest that cereal yield was most sensitive to CO₂ emissions, rainfall and temperature. In the long run, a 1% increase in temperature is associated with a 2.87% and 3.52% decrease in general and predicted estimates of cereal production, respectively. The dynamic ARDL simulations methodology provides a better understanding of the variability of cereal production in Malaysia as a result of climate change.     

Relationships among carbon emissions,economic growth,energy consumption and population growth: Testing Environmental Kuznets Curve hypothesis for Brazil,China, India and Indonesia

This study examines the impacts of income, energy consumption and population growth on CO₂ emissions by employing an annual time series data for the period 1970–2012 for India, Indonesia, China, and Brazil. The study used the Autoregressive Distributed Lag (ARDL) bounds test approach considering both the linear and non-linear assumptions for related time series data for the top CO₂ emitter emerging countries in both the short run and long run. The results show that CO₂ emissions have increased statistically significantly with increases in income and energy consumption in all four countries. While the relationship between CO₂ emissions and population growth was found to be statistically significant for India and Brazil, it has been statistically insignificant for China and Indonesia in both the short run and long run. Also, empirical observations from the testing of environmental Kuznets curve (EKC) hypothesis imply that in the cases of Brazil, China and Indonesia, CO₂ emissions will decrease over the time when income increases. So based on the EKC findings, it can be argued that these three countries should not take any actions or policies, which might have conservative impacts on income, in order to reduce their CO₂ emissions. But in the case of India, where CO₂ emissions and income were found to have a positive relationship, an increase in income over the time will not reduce CO₂ emissions in the country.     

Toward a Carbon Dioxide Neutral Industrial Park

The industrial park of Herdersbrug (Brugge, Flanders, Belgium) comprises 92 small and medium‐sized enterprises, a waste‐to‐energy incinerator, and a power plant (not included in the study) on its site. To study the carbon dioxide (CO₂) neutrality of the park, we made a park‐wide inventory for 2007 of the CO₂ emissions due to energy consumption (electricity and fossil fuel) and waste incineration, as well as an inventory of the existing renewable electricity and heat generation. The definition of CO₂ neutrality in Flanders only considers CO₂ released as a consequence of consumption or generation of electricity, not the CO₂ emitted when fossil fuel is consumed for heat generation. To further decrease or avoid CO₂ emissions, we project and evaluate measures to increase renewable energy generation. The 21 kilotons (kt) of CO₂ emitted due to electricity consumption are more than compensated by the 25 kt of CO₂ avoided by generation of renewable electricity. Herdersbrug Industrial Park is thus CO₂ neutral, according to the definition of the Flemish government. Only a small fraction (6.6%) of the CO₂ emitted as a consequence of fossil fuel consumption (heat generation) and waste incineration is compensated by existing and projected measures for renewable heat generation. Of the total CO₂ emission (149 kt) due to energy consumption (electricity + heat generation) and waste incineration on the Herdersbrug Industrial Park in 2007, 70.5% is compensated by existing and projected renewable energy generated in the park. Forty‐seven percent of the yearly avoided CO₂ corresponds to renewable energy generated from waste incineration and biomass fermentation.     

Towards Productive Cities: Environmental Assessment of the Food‐Energy‐Water Nexus of the Urban Roof Mosaic

Cities are rapidly growing and need to look for ways to optimize resource consumption. Metropolises are especially vulnerable in three main systems, often referred to as the FEW (i.e., food, energy, and water) nexus. In this context, urban rooftops are underutilized areas that might be used for the production of these resources. We developed the Roof Mosaic approach, which combines life cycle assessment with two rooftop guidelines, to analyze the technical feasibility and environmental implications of producing food and energy, and harvesting rainwater on rooftops through different combinations at different scales. To illustrate, we apply the Roof Mosaic approach to a densely populated neighborhood in a Mediterranean city. The building‐scale results show that integrating rainwater harvesting and food production would avoid relatively insignificant emissions (13.9–18.6 kg CO₂ eq/inhabitant/year) in the use stage, but their construction would have low environmental impacts. In contrast, the application of energy systems (photovoltaic or solar thermal systems) combined with rainwater harvesting could potentially avoid higher CO₂ eq emissions (177–196 kg CO₂ eq/inhabitant/year) but generate higher environmental burdens in the construction phase. When applied at the neighborhood scale, the approach can be optimized to meet between 7% and 50% of FEW demands and avoid up to 157 tons CO₂ eq/year. This approach is a useful guide to optimize the FEW nexus providing a range of options for the exploitation of rooftops at the local scale, which can aid cities in becoming self‐sufficient, optimizing resources, and reducing CO₂ eq emissions.     

The impact of trade openness on global carbon dioxide emissions: Evidence from the top ten emitters among developing countries

This study aims to analyze the relationship between carbon dioxide (CO₂) emissions, trade openness, real income and energy consumption in the top ten CO₂ emitters among the developing countries; namely China, India, South Korea, Brazil, Mexico, Indonesia, South Africa, Turkey, Thailand and Malaysia over the period of 1971–2011. In addition, the possible presence of the EKC hypothesis is investigated for the analyzed countries. The Zivot–Andrews unit root test with structural break, the bounds testing for cointegration in the presence of structural break and the VECM Granger causality method are employed. The empirical results indicate that (i) the analyzed variables are co-integrated for Thailand, Turkey, India, Brazil, China, Indonesia and Korea, (ii) real income, energy consumption and trade openness are the main determinants of carbon emissions in the long run, (iii) there exists a number of causal relations between the analyzed variables, (iv) the EKC hypothesis is validated for Turkey, India, China and Korea. Robust policy implications can be derived from this study since the estimated models pass several diagnostic and stability tests.     

Using LCA‐based Decomposition Analysis to Study the Multidimensional Contribution of Technological Innovation to Environmental Pressures

This article presents a general framework for macroenvironmental assessment, combining life cycle assessment (LCA) with the IPAT equation, and explores its combination with decomposition analysis to assess the multidimensional contribution of technological innovation to environmental pressures. This approach is illustrated with a case study in which carbon dioxide (CO₂) and nitrogen oxides (NO_x) air emissions from diesel passenger cars in Europe during the period 1990–2005 are first decomposed using index decomposition analysis into technology, consumption activity, and population growth effects. By a second decomposition, the contribution of a specific innovation (diesel engine) is calculated on the basis of the technology and consumption activity effects, through a technological comparison with a relevant alternative and the calculation of the rebound effect, respectively. The empirical analysis for diesel passenger cars highlights the discrepancies between the micro (LCA) and macro (IPAT‐LCA) analytical approaches. Thus, whereas diesel engines present a relatively less‐pollutant environmental product profile than their gasoline counterparts, total CO₂ and NO_x emissions would have increased partly as a consequence of their introduction, mainly driven by the increase in travel demand caused by the induced direct price rebound effect from fuel savings and fuel price differences. The counterintuitive result shows the need for such an analysis.     

辽宁省能源消费和碳排放与经济增长的关系

在广泛收集资料的基础上,对辽宁省的能源利用效率、能源消费强度与经济增长的关系进行探索,其目的为辽宁省的节能与CO2减排及经济的快速发展提供科学依据。结果表明:辽宁整体单位GDP能耗高出全国水平52%—70%,第二产业单位GDP能耗是第三产业的5.67—8.41倍,第一产业的7.2—9.0倍;辽宁能源利用率只有全国平均水平的60%左右,第二产业能源利用效率只有第一产业的11.89%,第三产业的12.60%;GDP年增长速率大于能源消费量年增长速率,能源投入增加促进了国民生产总值的提高,但是经济增长并不是完全依赖能源消费的增长;能源消费量与经济增长的关系,呈现出"N型"曲线特征,随着GDP的增加,能源消费量出现反复上升和下降过程,辽宁省能源消费和经济增长关系没有达到长期的均衡性,尚处于非平衡的发展阶段。     

Carbon Abatement and Emissions Associated with the Gasification of Walnut Shells for Bioenergy and Biochar Production

By converting biomass residue to biochar, we could generate power cleanly and sequester carbon resulting in overall greenhouse gas emissions (GHG) savings when compared to typical fossil fuel usage and waste disposal. We estimated the carbon dioxide (CO₂) abatements and emissions associated to the concurrent production of bioenergy and biochar through biomass gasification in an organic walnut farm and processing facility in California, USA. We accounted for (i) avoided-CO₂ emissions from displaced grid electricity by bioenergy; (ii) CO₂ emissions from farm machinery used for soil amendment of biochar; (iii) CO₂ sequestered in the soil through stable biochar-C; and (iv) direct CO₂ and nitrous oxide (N₂O) emissions from soil. The objective of these assessments was to pinpoint where the largest C offsets can be expected in the bioenergy-biochar chain. We found that energy production from gasification resulted in 91.8% of total C offsets, followed by stable biochar-C (8.2% of total C sinks), offsetting a total of 107.7 kg CO₂-C eq Mg^-1 feedstock. At the field scale, we monitored gas fluxes from soils for 29 months (180 individual observations) following field management and precipitation events in addition to weekly measurements within three growing seasons and two tree dormancy periods. We compared four treatments: control, biochar, compost, and biochar combined with compost. Biochar alone or in combination with compost did not alter total N₂O and CO₂ emissions from soils, indicating that under the conditions of this study, biochar-prompted C offsets may not be expected from the mitigation of direct soil GHG emissions. However, this study revealed a case where a large environmental benefit was given by the waste-to-bioenergy treatment, addressing farm level challenges such as waste management, renewable energy generation, and C sequestration.     

Decoupling Analysis of the Environmental Mountain—with Case Studies from China

The resource‐development trajectory of developed countries after the Industrial Revolution of the eighteenth and nineteenth centuries can be portrayed as an “environmental mountain” (EM). It is important for developing countries to decouple their resource use from economic growth and tunnel through the EM. In this study, we embedded the decoupling indicators for resource use and waste emissions into EM curves to quantify China's progress in tunneling through the EM over a specific time period. Five case studies regarding the conditions required for decoupling energy consumption, crude steel production, cement production, CO₂ emissions, and SO₂ emissions from economic growth in China were conducted. The results indicated that during 1985–2010 the trajectories of energy consumption, and CO₂ and SO₂ emissions in China met the requirements for tunneling through the EM, but the trajectories of cement and steel production did not. Based on these results, suggestions regarding China's environmental policies are provided to enable the country to tunnel through the EM.     

Environmental Kuznets Curve hypothesis and the role of globalization in selected African countries

The present study incorporates globalization and energy intensity into the CO₂ emissions function and investigates the presence of Environmental Kuznets Curve (EKC) in 19 African countries for the time period of 1971–2012. We have applied the ARDL bounds testing approach for cointegration to examine the long run relationship in the variables. Our results confirmed the presence of cointegration between the series in Africa, Algeria, Angola, Cameroon, Congo Republic, Ghana, Kenya, Libya, Morocco, Nigeria, South Africa, Sudan, Tanzania, Togo, Tunisia, Zambia and Zimbabwe. The results indicated the positive effect of energy intensity on CO₂ emissions in Africa, Algeria, Angola, Cameroon, Congo Republic, Ghana, Kenya, Libya, Morocco, Nigeria, South Africa, Sudan, Togo, and Tunisia while energy intensity declines CO₂ emissions in the case of Zambia and Zimbabwe. Globalization decreases CO₂ emissions in Africa, Angola, Cameroon, Congo Republic, Egypt, Kenya, Libya, Tunisia and Zambia but increases CO₂ emissions in Ghana, Morocco, South Africa, Sudan and Tanzania. The EKC exists in Africa, Algeria, Cameroon, Congo Republic, Morocco, Tunisia and Zambia but U-shaped relationship is found between economic growth and CO₂ emissions in Sudan and Tanzania.     

Challenges and opportunities for hydrogen production from microalgae

The global population is predicted to increase from ~7.3 billion to over 9 billion people by 2050. Together with rising economic growth, this is forecast to result in a 50% increase in fuel demand, which will have to be met while reducing carbon dioxide (CO₂) emissions by 50–80% to maintain social, political, energy and climate security. This tension between rising fuel demand and the requirement for rapid global decarbonization highlights the need to fast‐track the coordinated development and deployment of efficient cost‐effective renewable technologies for the production of CO₂ neutral energy. Currently, only 20% of global energy is provided as electricity, while 80% is provided as fuel. Hydrogen (H₂) is the most advanced CO₂‐free fuel and provides a ‘common’ energy currency as it can be produced via a range of renewable technologies, including photovoltaic (PV), wind, wave and biological systems such as microalgae, to power the next generation of H₂ fuel cells. Microalgae production systems for carbon‐based fuel (oil and ethanol) are now at the demonstration scale. This review focuses on evaluating the potential of microalgal technologies for the commercial production of solar‐driven H₂ from water. It summarizes key global technology drivers, the potential and theoretical limits of microalgal H₂ production systems, emerging strategies to engineer next‐generation systems and how these fit into an evolving H₂ economy.     

Decoupling environmental pressure from economic growth on city level: The Case Study of Chongqing in China

As cities represent the microcosms of global environmental change, it is very important for the global sustainable development by decoupling environmental pressure from economic growth on city level. In this paper, the municipality of Chongqing in China is employed as a case to show whether the decoupling of environmental pressures from economic growth has occurred in cities undergoing rapid economic growth; what is the level of decoupling; and what causes the observed degree of decoupling. Results show the following. (1) During the period of 1999–2010, decoupling from economic growth has been absolute for the emissions of SO₂, soot, and waste water, while it has been relative for total energy consumption, emissions of CO₂ and solid waste. (2) Compared with the period 2000–2005, decoupling level improved for all the six environmental pressures in the period 2005–2010. (3) Compared with China and other three municipalities of China, the overall decoupling level of Chongqing is above China’s average while below those of Beijing and Shanghai. (4) During the period 1999–2000, technological change was the dominate factor for decoupling Chongqing’s environmental pressure from economic growth, as it contributed 131.4%, 134.6%, 99.9%, 97.7%, 104.5% and 54.9% to the decoupling of total energy consumption, emissions of CO₂, SO₂, soot, waste water and solid waste, respectively; while economic structural change had very tiny effect to the decoupling of emissions of soot and SO₂, and it even had negative effect to that of total energy consumption, and emissions of CO₂ and waste water. Based on the above observations, we explain the difference in decoupling levels for different environmental pressures and suggest approaches for policy-makers on further promoting decoupling environmental pressure from economic growth.     

Scenario Analysis and Path Selection of Low-Carbon Transformation in China Based on a Modified IPAT Model

This paper presents a forecast and analysis of population, economic development, energy consumption and CO₂ emissions variation in China in the short- and long-term steps before 2020 with 2007 as the base year. The widely applied IPAT model, which is the basis for calculations, projections, and scenarios of greenhouse gases (GHGs) reformulated as the Kaya equation, is extended to analyze and predict the relations between human activities and the environment. Four scenarios of CO₂ emissions are used including business as usual (BAU), energy efficiency improvement scenario (EEI), low carbon scenario (LC) and enhanced low carbon scenario (ELC). The results show that carbon intensity will be reduced by 40–45% as scheduled and economic growth rate will be 6% in China under LC scenario by 2020. The LC scenario, as the most appropriate and the most feasible scheme for China’s low-carbon development in the future, can maximize the harmonious development of economy, society, energy and environmental systems. Assuming China''s development follows the LC scenario, the paper further gives four paths of low-carbon transformation in China: technological innovation, industrial structure optimization, energy structure optimization and policy guidance.