Empirical study on the determinants of CO2 emissions: evidence from OECD countries

This article empirically investigates the Environmental Kuznets Curve (EKC) for CO₂ emissions in the cases of 11 OECD countries by taking into account the role of nuclear energy in electricity production. The autoregressive distributed lag approach to cointegration is employed as the estimation method. Our results indicate that energy consumption has a positive impact on CO₂ emissions in most countries in the study. However, the impact of trade is not statistically significant. The results provide evidence for the role of nuclear power in reducing CO₂ emissions only in some countries. Additionally, although the estimated long-run coefficients of income and its square satisfy the EKC hypothesis in Finland, Japan, Korea and Spain, only Finland's EKC turning point is inside the sample period of the study, providing poor evidence in support of the EKC hypothesis.     

Environmental Kuznets Curve with Adjusted Net Savings as a Trade‐Off Between Environment and Development

The Environmental Kuznets Curve (EKC) hypothesises that emissions first increase at low stages of development then decrease once a certain threshold has been reached. The EKC concept is usually used with per capita Gross Domestic Product as the explanatory variable. As others, we find mixed evidence, at best, of such a pattern for CO₂ emissions with respect to per capita GDP. We also show that the share of manufacture in GDP and governance/institutions play a significant role in the CO₂ emissions–income relationship. As GDP presents shortcomings in representing income, development in a broad perspective or human well‐being, it is then replaced by the World Bank's Adjusted Net Savings (ANS, also known as Genuine Savings). Using the ANS as an explanatory variable, we show that the EKC is generally empirically supported for CO₂ emissions. We also show that human capital and natural capital are the main drivers of the downward sloping part of the EKC.     

Revisiting the environmental kuznets curve hypothesis: evidence from the ASEAN-5 countries with structural breaks

This paper tests if the Environmental Kuznets Curve (EKC) hypothesis exists for ASEAN-5 countries in an annual sample data that covers 1971–2013, by utilizing Auto Regressive Distributed Lag (ARDL) methodology. The empirical findings give support for the EKC hypothesis for Thailand only, after considering the structural breaks. Furthermore, the paper tests the EKC hypothesis for a panel data of the ASEAN-5 by adopting the Pooled Mean Group (PMG) methodology. The results show that the long-run estimates provide no evidence for the EKC hypothesis. Finally, the paper examines the causality between the CO₂ emissions and GDP. For individual countries, bidirectional causality was found in the case of Thailand and Malaysia, plus unidirectional causality running from GDP and squared GDP to CO₂ emissions was found for Indonesia, but a unidirectional causality running from CO₂ emissions to GDP and squared GDP was found for the Philippines, however, no causality effect was found for Singapore. Furthermore, the pairwise Dumitrescu and Hurlin Panel Causality test show a bidirectional effect between CO₂ emissions and both GDP in addition to squared GDP.     

Is nuclear energy clean? Revisit of Environmental Kuznets Curve hypothesis in OECD countries

A transition towards the adoption of clean energy sources in electricity generation is essential to reduce the emission of greenhouse gases. The present study aims to examine the EKC hypothesis by taking into account nuclear energy in 18 OECD countries for the period 1995–2015. This study employs panel dynamic Generalised Method of Moments (GMM) and panel Fully Modified Ordinary Least Squares (FMOLS) to investigate the effects of electricity production from nuclear source, electricity production from non-renewables and trade openness on CO₂ emissions. The empirical findings suggest that EKC hypothesis is valid in OECD countries where nuclear energy plays a pivotal role in protecting the environment. On the contrary, non-renewable energy sources tend to increase CO₂ emissions. Our results support the notion that electricity generated by nuclear source leads to lower CO₂ emissions without retarding the long run growth in OECD countries. The findings also provide important policy insights and recommendations not only for OECD countries, but also for developing countries in designing appropriate energy and economic policies.     

The impact of population on CO<Subscript>2</Subscript> emissions: evidence from European countries

This paper analyses the impact of population growth on CO₂ emissions in European Union countries. Traditionally, researchers have assumed a unitary elasticity of emissions with respect to population growth. In this study population is treated as a predictor in the model, instead of being included as part of the dependent variable (per capita emissions), thus relaxing the above-mentioned assumption of unitary elasticity. We also contribute to the existing literature by taking into account the presence of heterogeneity in the sample and considering a dynamic specification. The sample covers the period 1975–1999 for the current European Union members. Our results show that the impact of population growth on emissions is more than proportional for recent accession countries whereas for old EU members, the elasticity is lower than unity and non significant when the properties of the time series and the dynamics are correctly specified. The different impact of population change on CO₂ emissions for the current EU members should therefore be taken into account in future discussions of climate change policies within the EU.      

Does energy‐related aid affect emissions? Evidence from a global dataset

Donor countries have been using international aid in the field of energy for at least three decades. The stated objective of this policy is to reduce emissions and promote sustainable development in the global South. In spite of the widespread use of this policy tool, very little is known about its effect on emissions. In this paper we perform an empirical audit of the effectiveness of energy‐related aid in tackling CO₂ and SO₂ emissions. Using a global panel dataset covering 128 countries over the period 1971–2011 and estimating a parsimonious model using the Anderson and Hsiao estimator, we do not find any evidence of a systematic effect of energy‐related aid on emissions. We also find that the non‐effect is not conditional on institutional quality or level of income. Countries located in Europe and Central Asia do better than others in utilizing this aid to reduce CO₂ emissions. Our results are robust after controlling for the environmental Kuznets curve, country fixed effects, country‐specific trends, and time‐varying common shocks.     

Economic Growth and CO2 Emissions in the European Union

This paper examines the relationship between economic growth and CO₂ emissions in the European Union. A panel data analysis for the period 1981 to 1995 is applied in order to estimate the relationship between Gross Domestic Product (GDP) growth and CO₂ emissions in ten selected European countries. The analysis shows important disparities between the most industrialised countries and the rest. The results do not seem to support a uniform policy to control emissions; they rather indicate that a reduction in emissions should be achieved by taking into account the specific economic situation and the industrial structure of each EU member state.     

Do environmental benefits matter? Evidence from a choice experiment among house owners in Germany

Residential buildings strongly contribute to global CO₂ emissions due to the high energy demand for electricity and heating, particularly in industrialised countries. Within the EU, decentralised heat generation is of particular relevance for future climate policy, as its emissions are not covered by the EU ETS. We conducted a choice experiment concerning energy retrofits for existing houses in Germany. In the experiment, the approximately 400 sampled house owners could either choose a modern heating system or an improved thermal insulation for their home. We used standard and mixed logit specifications to analyse the choice data. We found environmental benefits to have a significant impact on choices of heating systems. However, they played no role in terms of insulation choices. Based on the estimated mixed logit model, we further obtained willingness-to-pay (WTP) measures for CO₂ savings.     

The impact of urbanization on CO2 emissions: Evidence from developing countries

This paper analyzes the impact of urbanization on CO₂ emissions in developing countries from 1975 to 2003. It contributes to the existing literature by examining the effect of urbanization, taking into account dynamics and the presence of heterogeneity in the sample of countries. The results show an inverted-U shaped relationship between urbanization and CO₂ emissions. Indeed, the elasticity emission-urbanization is positive for low urbanization levels, which is in accordance with the higher environmental impact observed in less developed regions. Among our contributions is the estimation of a semi-parametric mixture model that allows for unknown distributional shapes and endogenously classifies countries into homogeneous groups. Three groups of countries are identified for which urbanization's impact differs considerably. For two of the groups, a threshold level is identified beyond which the emission-urbanization elasticity is negative and further increases in the urbanization rate do not contribute to higher emissions. However, for the third group only population and affluence, but not urbanization, contribute to explain emissions. The differential impact of urbanization on CO₂ emissions should therefore be taken into account in future discussions of climate change policies.     

The Stochastic Convergence of CO<Subscript>2</Subscript> Emissions: A Long Memory Approach

In response to equity concerns surrounding the spatial distribution of CO₂ emissions and assumptions of CO₂ convergence within some climate models, this paper examines the convergence of CO₂ emissions within the OECD over the period 1870–2004. More specifically, using the Local Whittle estimator and its variants we examine whether relative per capita CO₂ emissions are fractionally integrated, that is they are long memory processes which, although highly persistant, may revert to the mean/trend in the long run. Our results suggest that CO₂ emissions within 13 out of 18 OECD countries are indeed fractionally integrated implying that they converge over time, albeit slowly. Interestingly though, the countries whose emissions are not found to be fractionally integrated are some of the highest polluters within the OECD, at least in per capita terms. Our results have implications both for future studies of CO₂ convergence and for climate policy.     

Openness and the Environmental Kuznets Curve: Evidence from China

This paper investigates the relationship in China between trade, growth and emissions using provincial-level data for water (chemical oxygen demand: COD) and air (sulphur dioxide: SO₂). It analyses the period 1990–2007 in three steps. First, the income ‘turning point’ of the Environmental Kuznets Curve (EKC) has been estimated using quadratic log function and obtained a turning point consistent with existing studies. Second, adopting Dean's (2002) simultaneous equations system, the relationships between trade, growth and emissions has been estimated and the results confirm the dominance of scale effects over technique effects. Third, the estimated per capita turning point for EKC is used to split the provincial industrial database into two groups (below and above turning point income) and simultaneous equations are estimated separately for them. The split sample provided limited support for the trade-induced emissions hypothesis for COD, but not for SO_2. At the provincial level rising incomes via increased levels of international trade were associated with falling COD due to the technique effect, so that rising incomes among the provinces tended to be associated with lower emissions. Stricter environmental regulations are required for growing incomes because they may encourage better production techniques.     

Is the Green Solow Model Valid for $$\hbox {CO}_{2}$$ Emissions in the European Union?

This paper addresses the \(\hbox {CO}_{2}\) emission patterns of the European Union from 1950 to 2010, and examines the validity of the Green Solow model, which simulates \(\hbox {CO}_{2}\) emissions growth by including only Solow forces and assuming emission intensity growth to be exogenous and constant. This study verifies that an environmental Kuznets curve (EKC) trajectory exists for per capita \(\hbox {CO}_{2}\) emissions in the European Union, that emission intensity growth is decreasing over time, and that the decreasing intensity growth reflects variations of the dependent variable in the specifications of the Green Solow model. The critique by Stefanski (On the mechanics of the Green Solow model. OxCarre Research Paper 47, OxCarre & Laval University, Oxford, 2013) of the Green Solow model assumption of exogenous and constant intensity growth is validated. The EKC is defined as the emissions plotted against income and emission intensity is defined as the ratio of emissions to income. The EKC and emission intensity share identical definitions and similar transition trajectories over time. The transition of the EKC trajectory and decline in emission intensity growth began before worldwide attention was focused on global warming.     

Functional sensitivity of testing the environmental Kuznets curve hypothesis

Conventional tests for the environmental Kuznets curve (EKC) hypothesis mostly apply a quadratic equation in modeling the non-linear relationship between environmental indices (such as air pollutants) and welfare measures (such as income per capita). If their inverted-U shaped pattern is empirically accepted with two significant regressors, the income per capita and its square transformation, the EKC hypothesis is supported. Using an OECD sample, this paper shows that the validity of testing the EKC hypothesis is sensitive to how we transform income non-linearly in sulfur and carbon EKC regressions. This paper carries out experiments on different powers of γ for transforming income non-linearly and concludes that only when 0 < γ < 1 and 1 < γ < 2 will the EKC regression demonstrate a testable non-linear cointegration relationship between the two air pollutants and income per capita. In the generalized EKC regressions estimated in this paper, although we find sulfur and carbon EKC patterns in the OECD sample, none of the EKC regressions using different γ is a cointegrating equation. This finding implies an inside critique to the EKC literature that failure of cointegration of the conventional EKC regression is not because of using the quadratic functional form, but because of the fundamentally spurious relationship between the trends of pollutants and income levels.     

Long-term Nexus Between Openness,Income, and Environmental Quality

In this paper we examine the dynamic relationship between income, trade, and environmental quality as measured by carbon dioxide (CO₂) emissions, disaggregated by source (oil, gas, and coal). Using time series data spanning from 1980 to 2006, 21 countries, including G7, BRIC, and middle and low income economies, we consistently find the existence of a long-run relationship between income, trade, and carbon emissions (from oil in particular). This is important because the Environmental Protection Agency (EPA) recently determined that CO₂ emissions indeed pose a threat to human health and welfare.     

Functional sensitivity of testing the environmental Kuznets curve hypothesis

Conventional tests for the environmental Kuznets curve (EKC) hypothesis mostly apply a quadratic equation in modeling the non-linear relationship between environmental indices (such as air pollutants) and welfare measures (such as income per capita). If their inverted-U shaped pattern is empirically accepted with two significant regressors, the income per capita and its square transformation, the EKC hypothesis is supported. Using an OECD sample, this paper shows that the validity of testing the EKC hypothesis is sensitive to how we transform income non-linearly in sulfur and carbon EKC regressions. This paper carries out experiments on different powers of γ for transforming income non-linearly and concludes that only when 0 < γ < 1 and 1 < γ < 2 will the EKC regression demonstrate a testable non-linear cointegration relationship between the two air pollutants and income per capita. In the generalized EKC regressions estimated in this paper, although we find sulfur and carbon EKC patterns in the OECD sample, none of the EKC regressions using different γ is a cointegrating equation. This finding implies an inside critique to the EKC literature that failure of cointegration of the conventional EKC regression is not because of using the quadratic functional form, but because of the fundamentally spurious relationship between the trends of pollutants and income levels.     

Does urbanization increase pollutant emission and energy intensity? evidence from some Asian developing economies

This paper aims to investigate the effects of urbanization on pollutant emissions and energy intensity in selected Asian developing countries after controlling for the effects of disaggregated (renewable and non-renewable) energy consumption, trade liberalization, and economic growth. We use both linear and nonlinear panel data econometric techniques and employ recently introduced mean group estimation methods, allowing for heterogeneity and cross-sectional dependence. However, to check the robustness of our panel results, we also apply the autoregressive distributed lag (ARDL)-bound testing approach to country-level data. In addition, the relationship between affluence and CO₂ emissions is examined in the context of the Environmental Kuznets Curve (EKC) hypothesis. The estimation results identify the population, affluence, and non-renewable energy consumption as major factors in pollutant emissions in Asian countries. However, the results of the EKC hypothesis show that when countries achieve a certain level of economic growth, their emissions tend to decline. Whereas nonlinear results show that renewable energy, urbanization, and trade liberalization reduce emissions, linear estimations do not confirm these outcomes. Thus, substitution of non-renewable for renewable energy consumption, cautious and planned urbanization programs and more liberal trading regimes may be viable options for sustainable growth of these developing Asian economies.     

CO2 emissions in Australia: economic and non-economic drivers in the long-run

Australia has sustained a relatively high economic growth rate since the 1980s compared to other developed countries. Per capita CO₂ emissions tend to be highest amongst OECD countries, creating new challenges to cut back emissions towards international standards. This research explores the long-run dynamics of CO₂ emissions, economic and population growth along with the effects of globalization tested as contributing factors. We find economic growth is not emission-intensive in Australia, while energy consumption is emissions intensive. Second, in an environment of increasing population, our findings suggest Australia needs to be energy efficient at the household level, creating appropriate infrastructure for sustainable population growth. High population growth and open migration policy can be detrimental in reducing CO₂ emissions. Finally, we establish globalized environment has been conducive in combating emissions. In this respect, we establish the beneficial effect of economic globalization compared to social and political dimensions of globalization in curbing emissions.     

Abatement and Allocation in the Pilot Phase of the EU ETS

We use historical industrial emissions data to assess the level of abatement and over-allocation that took place across European countries during the pilot phase (2005–2007) of the European Union Emission Trading Scheme. Using a dynamic panel data model, we estimate the counter factual (business-as-usual) emissions scenario for EU member states. Comparing this baseline to allocated and verified emissions, we find that both over-allocation and abatement occurred, along with under-allocation and emissions inflation. Over the three trading years of the pilot phase we find over-allocation of approximately 280 million EUAs and total abatement of 247 Mt CO₂. However, we calculate that emissions inflation of approximately 73 Mt CO₂ also occurred, possibly due to uncertainty about future policy design features.     

A fair share: Burden-sharing preferences in the United States and China

Using a sequential discrete choice experiment, we investigate preferences for distributing the economic burden of reducing CO₂ emissions in the two largest CO₂-emitting countries: the United States and China. We asked respondents about their preferences for four burden-sharing rules to reduce CO₂ emissions according to their country's relative (1) historical emissions, (2) income level, (3) emissions per capita, and (4) current emissions. We found that respondents overall favored the rule that was least costly for their country. In addition, the willingness to pay was much higher in China, suggesting that how mitigation costs are shared across countries is more important for Chinese than for Americans. To some extent the willingness to pay varies with socioeconomic characteristics and attitudes. For example, university-educated respondents in the United States are willing to pay more for the rule that is the least costly for their own country, compared with those with a lower education level. At the same time, the ranking of the two most preferred rules are generally robust across all socioeconomic groups within each country.