Hydropower, human capital, urbanization and ecological footprints nexus in China and Brazil: evidence from quantile ARDL

Can clean energy and technology address environmental sustainability in G7 under the pre-set of human development?

Climate change presents challenges for both industrialized and developing nations, primarily due to insufficient pollution control. Increased fossil fuel usage escalates pollution levels, emphasizing the need to integrate more renewable energy into the energy mix, particularly to reduce carbon emissions. Consequently, public investment in renewable energy becomes pivotal to enhance the necessary technology for green energy production. Human development and technological progress play a crucial role in advancing green energy and ensuring environmental sustainability. This study addresses whether clean energy and technology can foster ecological sustainability in the G7 while considering human development. Findings emphasize the significance of public investments in renewable energy projects, technical innovation, and human development. Such investments are essential for augmenting renewable energy shares and lowering carbon emissions in the long run. The study proposes relevant policies to help G7 nations achieve United Nations Sustainable Development Goals related to green energy transition (SDG-7), environmental sustainability (SDG-13), and innovation (SDG-9). In essence, prioritizing renewable energy investment and innovation is imperative for sustainable development.

Do life expectancy and hydropower consumption affect ecological footprint? Evidence from novel augmented and dynamic ARDL approaches

Human activities threaten the future of the ecosystem by emitting pollution to the air, water, and soil. Considering the increasing ecological footprint (EF), the study focuses on investigating the role of life expectancy and hydropower consumption by controlling also income, trade openness, and globalization on the environment under the environmental Kuznets curve (EKC) hypothesis for Turkey during 1971-2018. In this context, the study performs recently developed augmented autoregressive distributed lag (AARDL) and dynamic ARDL (DARDL) methods. The results show that (i) life expectancy increases the environmental pressure; (ii) hydropower consumption has no effect on the EF; (iii) globalization and trade openness reduce the EF; (iv) the EKC hypothesis is valid, but the estimated turning point lies between USD 19,914 and USD 20,571, which is far from the sample period in Turkey. From the overall results, it can be concluded that Turkey cannot solve environmental problems with insufficient income levels, an increasing elderly population, and ineffective use of hydropower. Hence, Turkey should rely on income much more, use hydropower much more efficiently, and benefit from the spillover effect of technological innovations related to globalization and foreign trade to significantly reduce the EF.

EKC hypothesis testing and environmental impacts of transportation infrastructure investments in China, Turkey, India, and Japan

A key strategy for social development and sustainable urban expansion is building sustainable and affordable transport systems. In this study, we aim to test the validity of the environmental Kuznets curve (EKC) hypothesis and reveal the impact of infrastructure investment in transportation systems in China, Turkey, India, and Japan over the period 1995-2020 on environmental degradation. According to dynamic ordinary least squares (DOLS) method analysis, per capita GDP and per capita GDP³ have a significant positive impact on per capita CO₂ emission, while per capita GDP² has a significant adverse impact on per capita CO₂ emission. These results confirm the validity of the N-shaped EKC assumption, while inconsistent with the results of the FMOLS technique, showing that per capita GDP is significantly positive, while per capita GDP² and per capita GDP³ have a significant negative impact on per capita carbon emissions. Moreover, as clarified by the fully modified ordinary least squares (FMOLS) and DOLS methods, road infrastructure investment (RO), aviation infrastructure investment, trade openness, and foreign direct investment (FDI) have significant positive effects, while railway infrastructure investment (RA) has a significant negative effect on per capita carbon emission. Country-level estimates of per capita carbon emission-based DOLS strategies in the model show that only China and Japan have N-shaped EKC hypothesis. Road infrastructure investment, aviation infrastructure investment, and trade openness have significant positive effects, while railway infrastructure investment has a significant negative effect on per capita CO₂ emission in selected central and east Asian countries. The latest electrified rail systems are well thought out and less polluting, so the contribution of rail infrastructure investment to the transport mix can support sustainable and safe transport systems at city center and intercity levels and reduce environmental pollution in central and east Asian countries. Moreover, the implementation of the basic environmental settings of trade agreements should be strengthened to condense the growing impact of free trade on environmental pollution.

Testing the environmental Kuznets curve hypothesis in terms of ecological footprint and CO2 emissions through energy diversification for Turkey

This research work analyzes the relationship between environmental degradation, economic growth, trade openness, primary energy consumption, coal consumption, and hydroelectricity consumption in Turkey from 1971 to 2015 using the autoregressive distributed lag (ARDL) time series approach through the hypothesis of the environmental Kuznets curve (EKC). Carbon dioxide (CO₂) emissions and ecological footprint are both used as indicators of environmental degradation, which employs six different models. According to the results found in this study, while trade openness increases CO₂ emissions, it decreases ecological footprint in the long-run. Coal consumption raises both CO₂ emissions and ecological footprint. While hydroelectric energy reduces CO₂ emissions, it has no effect on the environment. The results demonstrate that the EKC hypothesis is correct for both CO₂ emissions and Turkey's ecological footprint. The threshold points are investigated as $18,704, $16,361, and $13,571 in models, where CO₂ emissions are the dependent variable. In models where the ecological footprint is the dependent variable, the investigated threshold points of $11,824, $11,821, and $15,476 are higher than the gross domestic product (GDP) per capita during the analysis periods. Furthermore, the findings highlight the importance of renewable energy use in reducing environmental degradation and coal use in increasing environmental degradation. These findings can shed light on the importance of transition to renewable energy sources (i.e., hydroelectricity consumption), from fossil fuels (i.e., coal consumption), related to future planning in energy diversification for Turkey.

Characteristics, regional differences, and influencing factors of China's water-energy-food (W-E-F) pressure: evidence from Dagum Gini coefficient decomposition and PGTWR model

Water, energy, and food security are global concerning issues especially in China. To promote regional environmental management cooperation as well as find resource security influencing factor differences among regions, this paper calculates the water-energy-food (W-E-F) pressure, find W-E-F pressure's regional differences, and the influencing factors by Dagum Gini coefficient decomposition and geographically and temporally weighted regression model for panel data (PGTWR). First, the temporal trend of W-E-F pressure is decreasing and then increasing during 2003-2019; pressure in the eastern provinces is significantly higher than in other provinces and structurally energy pressure is the dominant resource pressure in W-E-F in most provinces. Besides, inter-regional differences are the main source of regional differences in China's W-E-F pressure, particularly for the inter-regional differences between eastern regions and other regions. In addition, there are obvious spatio-temporal heterogeneity effects of population density, per capita GDP, urbanization, energy intensity, effective irrigated area, and forest cover on W-E-F pressure. Balancing regional development gaps and developing differentiated resource pressure mitigation strategies based on the characteristics of different regional drivers are of great importance.

Role of nuclear energy in carbon mitigation to achieve United Nations net zero carbon emission: evidence from Fourier bootstrap Toda-Yamamoto

In this communication, the time series data of three major countries USA, France, and Japan from 1965 to 2020 for CO₂ emission, GDP, and nuclear energy (NE) are evaluated. It also analyzed and validated the EKC hypothesis while using nuclear energy for electricity generation. Fourier ARDL is used to investigate the hypothesis criteria, and the Fourier bootstrap Toda-Yamamoto (FBTY) causality test is used for causal linkage between the variables as well as the wavelet coherence; it is also presented the time and frequency dependency of the variables. The CO₂ mitigation by using the NE is also assessed for all three countries and assessed that the France, Japan, and USA mitigated the CO₂ per year is 0.0463 million metric ton (MMT), 0.0239 and 0.0728 MMT per year respectively. Similar to that the SO₂ is reduced by using the NE is 24.322, 43.527, and 132.592 MMT/year, and NOx is reduced by approximately 0.2847, 0.147, and 0.4478 MMT/year by France, Japan, and USA respectively by applying the NE for power generation. The evidence of the EKC, Fourier bootstrap and Toda-Yamamoto clarifies the important role of nuclear energy in terms of carbon mitigation to achieve UN net zero carbon emission by 2050. Hence, in order to meet the UN target of net zero carbon emission by 2050, the USA and Japan should increase the production of nuclear energy as France meets its 74.1% energy demand through NE by validating the EKC hypothesis; on the other hand, all the three countries should increase the production of tidal energy due to their geographical location as tides are much more predictable than wind and sun keeping in consideration to the expenses incurred and a full proof plan for disposing NE residuals in a safe place as NE residuals are highly radioactive and contains traces of thorium and uranium.

The effect of transport infrastructure (road, rail, and air) investments on economic growth and environmental pollution and testing the validity of EKC in China, India, Japan, and Russia

A key factor in social development and sustainable urban expansion is the establishment of sustainable and affordable transport systems. This study aims to investigate the impact of transport infrastructure investment on environmental degradation and economic growth and to test the validity of the EKC hypothesis in China, India, Russia, and Japan over the period 1995-2020. The results show that GDP has a significant positive effect, and GDP² and GDP³ have significant adverse effects on environmental degradation, respectively. These results confirm the validity of the inverted U-shaped EKC hypothesis in selected emerging Asian economies. Rail infrastructure investment has significant adverse effects, while road infrastructure investment and aviation infrastructure investment have significant positive effects on environmental degradation. Likewise, the impact of investment in transport infrastructure system (roads, rail, and aviation) on economic growth is positive and statistically significant. Country-level estimates confirm the validity of the inverted U-shaped EKC hypothesis in China, India, and Russia, while the N-shaped EKC is only valid in Japan. Investments in rail infrastructure based on modern rail systems that run on electricity are believed to be less polluting in the transport mix, help create sustainable and safe transport systems, and reduce emissions at the urban and intercity levels in emerging Asian countries. In addition, the growing impact of free trade on environmental pollution should be strengthened to harmonize the strict enforcement of environmental conditions dominated by trade agreements.

Assessing the spillover effects of research and development and renewable energy on CO2 emissions: international evidence

The primary motivation of this paper is the lack of consensus on the impact of renewable energy (RE) and research and development (R&D) expenditure on CO2 emissions in the literature. Current literature has mostly ignored the spillover effect of R&D on CO2 emissions by increasing the intensity effect of technology, leading to biased results. Further, little is known about the impact of previous epidemics on CO2 emissions. This study fills these gaps by evaluating the spillover effects of RE and R&D on CO2 emissions in a global panel of 54 countries from 2003 to 2017. Using a two-way time- and spatial-fixed-effects panel analysis, we find both income-induced and scale effects of economic growth are present in our panel, though the scale effect is the dominant one. Our findings indicate that economic growth increases CO2 emissions at a decreasing rate, validating the Environmental Kuznets Curve hypothesis, and that urbanization and foreign trade worsen the environment. We also find that epidemic episodes before COVID-19 had a nonsignificant impact on CO2 emissions internationally. More importantly, our results confirm the presence of both the intensity and scale effects of R&D, with the intensity effect being the dominant one. We find overwhelming evidence that global R&D investment led to an overall (direct plus spillover) reduction of CO2 emissions, driven by its spillover effect, through two channels: RE and economic growth. Finally, we find that RE installations assist with reducing CO2 emissions internationally, though RE composition and state of R&D can lead to different findings. Our findings have significant policy implications for sustainable development. Our RE and R&D-spillover results support the policy recommendation of shifting to high-tech clean energy sources.

The ecological impact assessment of globalization dimensions and human capital: a dynamic approach in the case of selected fossil fuel-rich countries

The aggravation of climatic damage, the rise in pollution, and global warming have prompted investigation of factors leading to the increase in human demand on natural resources. Numerous studies have dealt with the connections linking human action with the environmental impact, but this research field remains insufficiently documented. Human resources constitute the center of decision to reduce the ecological footprint, but studies on the impact of human capital and the social and human dimension of globalization on environmental sustainability have been insufficiently analyzed. Therefore, the aim of this study is to verify the capacity of human capital and the social dimension of globalization in addition to its political and economic ones to mitigate environmental degradation. The study referred to the FMOLS, DOLS, and PMG-ARDL methods applied to 13 fossil fuel-rich countries spanning the period 1992-2017 and applied a set of robustness tests based on the cross-section dependence test, unit root tests, and Johansen combined test. The findings, based on FMOLS and DOLS techniques, demonstrate that human capital exerts positive long-term influence upon ecological footprint in the case of fossil fuel-rich countries. Globalization does not significantly impact ecological footprint: only political globalization is able to decrease deterioration in the environment, and neither economic nor social globalizations have an effect. When applying the PMG-ARDL approach, the results supported those derived from FMOLS and DOLS methods and revealed that human capital positively affects ecological footprint in the long term but without significant short-term effects. Our results also showed that globalization is beneficial for high-income countries and harmful for middle-income countries in terms of mitigating environmental degradation. So, the reduction of the ecological footprint in the fossil fuel-rich economies remains dependent on the actions taken by political decision-makers at the international level and on the awareness of human capital of the urgency of mitigating environmental degradation. A set of recommendations in favor of environmental sustainability, in particular those relating to human action and which can serve decision-makers, were formulated in this study.

Empirical analysis of the impact of China-Japan-South Korea transportation infrastructure investment on environmental degradation and the validity of the environmental Kuznets curve hypothesis

Building sustainable and affordable transport systems is a key issue for social development and sustainable urban expansion. The study used dynamic ordinary least squares (DOLS) and fully modified ordinary least squares (FMOLS) to examine the impact of transport infrastructure investment on environmental degradation in China, Japan, and South Korea over the period 1995-2020 and the validity of the EKC hypothesis. The results show that GDP has a significant positive effect, and GDP2 and GDP3 have significant adverse effects on environmental degradation, respectively. These results confirm the validity of the inverted U shaped EKC hypothesis in selected Asian countries. Road infrastructure investment has a significant positive effect, while railway infrastructure investment has a significant adverse effect on environmental degradation. Air infrastructure investment and trade opening have a progressive and statistically significant impact on environmental pollution. Modern rail systems that run on electricity are considered less polluting, so the share of rail infrastructure investment in the transport mix can help build sustainable and safe transport systems at the city Centre and intercity levels and reduce emissions in Asian countries. Moreover, strict enforcement of the prevailing environmental conditions of trade agreements should be encouraged to reduce the increasing impact of free trade on environmental pollution.