Does Climate Change Cause an Upsurge in Food Prices?

Climate change is the reason behind most contemporary economic problems. The rising inflationary pressures in the food sector are one of these problems, and stable food prices are a necessity for economic development and social cohesion in societies. Therefore, this study analyzes the relationship between food prices and climate change in Nigeria by using various non-linear and quantile-based methods and data from 2008m5 to 2020m12. The empirical findings indicate that (i) there is a time- and frequency-based dependence between food prices and some explanatory variables, including climate change (i.e., temperature). (ii) At higher quantiles, temperature, oil prices, food exports, monetary expansion, global food prices, agricultural prices, and fertilizer prices stimulate food prices. (iii) The increase in food prices due to the rise in temperature and the difficulties in agriculture indicate that the heatflation phenomenon is present in Nigeria. The evidence outlines that Nigerian decisionmakers should adopt a national food security policy that considers environmental, agricultural, and monetary factors to stabilize food prices.

Impact of renewable energy investments in curbing sectoral CO2 emissions: evidence from China by nonlinear quantile approaches.

The study analyzes the impact of renewable energy investments (RENIV) on the environment in China. In doing so, the study uses sectoral carbon dioxide (CO2) emissions as the environment indicator, considers RENIV as the explanatory variable, includes monthly data from 2004/1 to 2020/6, runs quantile on quantile regression approach as the fundamental model, and further performs quantile regression for the controlling. The study reveals that RENIV curb CO2 emissions in all sectors at higher levels of sectoral CO2 emissions. Also, RENIV have a varying impact based on quantiles and sectors. Moreover, the results are robust based on the alternative approach. Thus, RENIV have a significantly decreasing impact on sectoral CO2 emissions in China. Accordingly, China policymakers should continue to focus on providing a decrease in energy and industrial sector CO2 emissions as the highest emitting sectors.

Convergence of Income Inequality in OECD Countries Since 1870: A Multi-Method Approach with Structural Changes.

This paper aims to examine convergence of income inequality in 21 OECD countries using several empirical techniques. In particular, we have used a new panel stationarity test, which allows for structural changes and cross-sectional dependence to examine the stochastic convergence of income inequality. We also employed a time series approach, residual augmented least squares-Lagrange multiplier unit root test. The empirical results show evidence for absolute, conditional, and sigma convergence. The conditional convergence test results suggest that countries are converging, but conditional on the two structural factors-economic and population growth. The stochastic convergence test results indicate the existence of convergence at the country-specific level. The results further confirm the existence of convergent clubs among OECD countries.

Is reducing fossil fuel intensity important for environmental management and ensuring ecological efficiency in China?

Since China is a country with high environmental pollution, researchers have intensively studied China's environmental problems using various environmental indicators such as carbon emissions and ecological footprint. Unlike previous literature, this study analyzes the effects of economic growth, globalization, foreign direct investment, and fossil energy intensity on ecological efficiency in China. As an innovation to the literature, the study examines the Chinese ecosystem simultaneously with its economic and environmental aspects by focusing on ecological efficiency. To this end, the study applies dynamic autoregressive distributed lag (DARDL) simulations and kernel-based regularized least squares (KRLS) methods for the period from 1990 to 2018. The results of the DARDL simulations show that globalization, and economic growth enhance ecological efficiency in China. The findings also demonstrate that both foreign direct investment and fossil fuel intensity have a negative impact on environmental quality in China. Based on these results, the study suggests that the Chinese government should adopt policies to channel foreign direct investment into environmentally friendly production, reduce fossil fuel intensity, and improve ecological efficiency by making use of environmentally friendly technologies provided by globalization and economic development.

On the convergence of ecological footprint in African countries: New evidences from panel stationarity tests with factors and gradual shifts.

Convergence of the environmental indicators has been one of the significant research areas for researchers since the study of Strazicich and List (2003) was published. Earlier papers have concentrated on investigating the existence of the convergence of indicators of the environment by using carbon emissions as a pollution indicator. However, some researchers have criticized the use of carbon emission as a one-dimensional indicator and proposed using ecological footprint as a more comprehensive indicator. The primary aim of this paper is to examine whether stochastic convergence of ecological footprint exists in 49 African countries from 1973 to 2018 by employing a battery of traditional stationarity methods and a newly proposed stationary method with smooth shifts and a combination of p-values. The empirical results show that panel findings of the conventional stationarity test with no structural shifts reveal that ecological footprint follows a stationary process. In contrast, panel findings of the traditional stationarity method with sharp and smooth changes and the newly developed stationary method with smooth shifts and a combination of p-values reveal that ecological footprint follows a non-stationary process. Moreover, the majority of individual results show that the ecological footprint follows a convergent pattern in 38 African countries, whereas it follows a divergent pattern in the remainder. Therefore, the main finding indicates the stochastic convergence of ecological footprint in African countries is validated. The policy outcomes of the empirical results are given in the body of the paper.

On the persistence of shocks to global CO2 emissions: a historical data perspective (0 to 2014).

Anthropogenic emissions of carbon dioxide (CO2) are the most important greenhouse gas. However, until now, no research has investigated the persistence of global CO2 emissions over a very long period of time. This work aims to fill this gap by examining the persistence of shocks to global CO2 emissions with a dataset of more than 2000 years. To this end, the study applies a battery of unit root tests by considering sharp and smooth structural shifts as well as the frequency domain properties of the series. Lee-Strazicich method results reveal that sharp break dates relate to the influenza pandemic of 1557 and the invention of the steam engine in 1712, and these historical events led to changes in the trend function of CO2 emissions. The findings of the Fourier Lagrange Multiplier and Fourier wavelet unit root tests illustrate that global CO2 emissions contain a unit root and do not exhibit mean-reverting behavior, thus external shocks have permanent effects on CO2 emissions. The results suggest that a reduction in global CO2 emissions is possible if effective environmental and energy policies established in international meetings such as Rio Conference, Kyoto Protocol Paris Agreement, and the United Nations Sustainable Development Summit are properly implemented.

Convergence analysis of ammonia emissions by sector and fuel source in OECD countries from 1750 to 2019 using a new Fourier-centric wavelet approach.

Although ammonia emissions are not as huge as carbon and methane emissions, they pose significant threats to ensuring environmental sustainability and productivity. However, the existing literature has paid less attention to the underlying characteristics of ammonia emissions. The chief target of this study is to investigate the stochastic convergence of ammonia emissions at the aggregate level, by sector, and by fuel source in 37 Organization for Economic Cooperation and Development countries for more than two centuries of data. Using a newly proposed Fourier-augmented wavelet unit root test, the empirical findings reveal that the relative ammonia emissions series in most Organization for Economic Cooperation and Development countries follow the unit root process in the aggregate, sectoral, and fuel-specific analyses. Therefore, these findings refer to the existence of divergence, while stochastic convergence does not exist in most cases. Having a divergent pattern of ammonia emissions has several policy implications for policymakers in the context of environmental sustainability. (i) Relative ammonia emission cannot revert to its steady-state path without policy intervention, (ii) policymakers have a chance of affecting the dynamics of ammonia emissions in Organization for Economic Cooperation and Development countries. (iii) As a policy response, the study recommends the pursuant of national environmental policies with consideration to the unique characteristics of the individual countries as the non-existence of convergence of environmental series could result in a diverse level of consciousness of environmental degradation among countries with divergent patterns on emissions levels.

Wavelet and Fourier augmented convergence analysis of methane emissions in more than two centuries: implications for environmental management in OECD countries.

Addressing the challenges posed by pollutants is necessary to achieve Sustainable Development Goal 13, which involves climate change mitigation and enhancement of environmental quality. The convergence analysis of a pollutant provides information that can be useful to how to handle that pollutant across countries or regions, and previous studies mainly focused on carbon emission. However, the second most significant greenhouse gas, methane emission, was mostly ignored. The primary objective of this research is to investigate whether stochastic convergence of methane emissions is valid in 37 OECD (Organisation for Economic Co-operation and Development) countries using a dataset of more than two centuries. The results obtained by using a set of traditional unit root tests and a newly proposed wavelet unit root test with a Fourier function provide overwhelming evidence for these countries' divergence of methane emissions. The policy implications resulting from the empirical findings for environmental management are discussed in the relevant sections of the paper.

Stochastic convergence in carbon emissions based on a new Fourier-based wavelet unit root test.

Most of the existing studies on stochastic convergence of emission have not adequately considered smooth structural changes. The primary purpose of this paper is to examine the validity of stochastic convergence at different income levels by recently proposed Fourier-based wavelet augmented Dickey-Fuller test with smooth shifts. Empirical results can be summed up as follows: (i) carbon emission per capita follows the stationarity process in 35 high-income countries, while carbon emission per capita follows the stationarity process in 27 upper-middle-income countries; (ii) besides, carbon emission per capita follows stationarity process in 30 lower-middle-income countries, while carbon emission per capita follows stationarity process in 13 low-income countries; (iii) in light of these findings, it can be said that stochastic convergence among different income groups is valid. The implications of the empirical findings for environmental planning and management are discussed in the body of the paper.

Does democracy help reduce environmental degradation?

The main purpose of this study is to examine the democracy-environmental degradation nexus in 26 Organization for Economic Cooperation and Development (OECD) countries from 1990 through 2015 by using panel data estimation methods, performing well under cross-sectional dependence. Empirical results are as follows: (i) Tests show that cross-section dependence exists among panel members, and slope coefficients are heterogeneous, respectively, and (ii) long-term coefficient estimation results with Augmented Mean Group estimator show that democracy, non-renewable energy consumption, and real income per capita have statistically significant negative effects on environmental quality, whereas renewable energy consumption has a positive effect. There is also no statistically significant relationship between urbanization and environmental quality. These findings show the poor functioning of democracy in addressing environmental issues among OECD countries; therefore, raising environmental quality conflicts with the Sustainable Development Goals (SDGs) of creating strong institutions and economic growth targets. Moreover, promoting renewable energy consumption may be an effective alternative in reducing environmental degradation; therefore, it can be said that promoting clean energy use and raising the SDG environmental quality targets are in harmony.

Revisiting the Environmental Kuznets Curve hypothesis in OECD countries: the role of renewable, non-renewable energy, and oil prices.

Environment-economic growth nexus is one of the main concerns of the researchers in the modern era. Although there are several studies in this field, discussions are far from being reached a consensus. The main purpose of this study is to investigate the role of economic growth, renewable and non-renewable energy consumption, oil prices, and trade openness on CO2 emissions in 25 Organization for Economic Co-operation and Development (OECD) countries over the period 1990-2014. We provide a comparative panel data evidence using both the first- and second-generation estimation methods. The Fully Modified Ordinary Least Squares (FMOLS) and Dynamic Ordinary Least Squares (DOLS) estimations indicate that the Environmental Kuznets Curve (EKC) hypothesis is valid in OECD countries. However, the Augmented Mean Group (AMG) estimator revealed that the EKC hypothesis is invalid. The AMG estimator is a second-generation estimator and provides robust results under cross-sectional dependence compared to the first-generation methods; therefore, the EKC hypothesis is invalid. Our additional findings show that rising renewable energy consumption and oil prices mitigate CO2 emissions while non-renewable energy consumption increases it according to all estimators. No significant relationship is found between trade openness and CO2 emissions.

Revisiting the convergence of carbon emission phenomenon in OECD countries: new evidence from Fourier panel KPSS test.

The environmental Kuznets curve (EKC) hypothesis which was developed by Grossman and Krueger implies that clean environment demand increases over a certain level of income. Convergence of carbon emission can be considered an extension of EKC hypothesis, which emphasizes that the carbon emissions of countries will converge to a certain level. Convergence is important for the identification of the trend of carbon emission and to design emission abatement policies. This study investigates the stochastic convergence of per capita carbon emission in Organization for Economic Co-operation and Development (OECD) countries for 1960-2014 under cross-sectional dependence by using recently developed panel data methods. Empirical results are as follows: (i) per capita carbon emission is generally non-stationary according to the CADF test and the CIPS test. (ii) Panel KPSS test indicates that carbon emission per capita is overwhelmingly stationary in both country-specific and panel levels; (iii) Fourier panel KPSS test indicates that per capita carbon emission is overwhelmingly stationary at the country-specific level and non-stationary at the panel level. These findings are strongly in favor of convergence of per capita carbon emission among OECD countries. Consequently, it can be said that emission abatement policies aren't essential among these countries.