Recently, there has been significant research interest in the empirical formulations of the environment-income relationship using both global and disaggregated data. Advances in methods and availability of better and more extensive data make the old topic of growth and environment a unique field for Environment and Development Economics, among other journals. Conventionally, the environmental Kuznets curve has been important in testing for emissions of many pollutants in many different countries. Now, policy and institutional data including transparency variables are available, making many social and economic factors interesting for policy analysts. In light of these advances, and the existing associated empirical problems in analyzing the income-environment relationship, the key findings of each paper in this special issue are discussed and connected to the related areas of research interest.

The Fifth IPCC Assessment Report estimates the world's ‘carbon budget’, which is the cumulative amount of anthropogenic CO2 emissions limiting global warming below 2°C. We model this carbon budget as a resource asset depleted by annual GHG emissions, and estimate the user cost associated with depletion. For constant emissions, social welfare increases US$3.3 trillion (6 per cent of global GDP) over the business as usual scenario of growing emissions, and the carbon budget's lifetime increases from 18 to 21 years. For declining emissions, the gain is US$10.4 trillion (19 per cent of global GDP), and the budget's lifetime is 30 years. Extending indefinitely the lifetime of the carbon budget would require emissions to fall exponentially by 4.8 per cent or more. Although the Paris Agreement abatement pledges will generate social gains of US$2–2.5 trillion (4–5 per cent of world GDP), they are insufficient to prevent depletion of the 2°C global carbon budget by 2030.

Comprehensive Investment (CI) may provide an indicator of future changes in a country's per capita consumption. The authors explore the utility of the CI indicator for Australia by constructing CI data since 1861 and by estimating their relationship with changes in future consumption over periods of 50 years ahead. The CI measures include changes in natural, produced and human capital, and make allowance for exogenous technological progress. The results are used to consider how Australia's natural capital exploitation influenced the consumption of future generations. Further, the authors gauge if low CI relative to other leading OECD countries resulted in lower consumption levels in Australia over time than feasible, had it saved more.

The authors adopt a new approach to modeling the relationship between emissions and income using long-run per capita growth rates. This approach allows them to test multiple hypotheses about the drivers of per capita emissions in a single framework and avoid several of the econometric issues that have plagued the environmental Kuznets curve literature. They estimate models for carbon and sulfur dioxide emissions. They can reject restricted models that omit either growth or beta convergence effects. Although the term representing the environmental Kuznets effect is statistically significant for per capita carbon and sulfur dioxide emissions, the estimated income per capita turning points are out of the sample for the full data set.

Climate regulations tend to target energy-intensive sectors whose products are widely used in industrial production as intermediate inputs, and carbon abatement may be partially offset by intermediate input-led leakage. This paper aims to examine the impact of intermediate input linkages on carbon leakage both theoretically and empirically. The theoretical part develops a Harberger-type model with an input-output linkage structure, identifies four leakage effects and derives closed-form solutions for these leakage effects. Its empirical part builds a computable general equilibrium model of China's economy and introduces structural decomposition analysis to link the theoretical and empirical models. When imposing a carbon price on the electricity generation sector, our results show significant sectoral carbon leakage. Our decomposition analysis further suggests that such leakage is mainly through the production substitution effect and the multiplier effect. Our results highlight the importance of sectoral linkage when discussing the carbon leakage issue of climate policies.

This paper studies the effect of carbon leakage on the environmental Kuznets curve (EKC) using satellite nighttime light data. It shows that nighttime lighting is an important variable for estimating carbon dioxide emissions that is superior to other existing indicators and covers all countries in the world, finding evidence of an inverted-U shaped relationship between light and, thus, greenhouse gas emissions and income, with a turning point at approximately US$50,000. However, the relationship is primarily driven by changes in the structure of international trade, implying strong carbon leakage effects. Consequently, environmental regulations that become operative in only one part of the world may fail without global coordination.

This paper aims to test the relation among militarization, CO2 emissions, economic growth and energy consumption in G7 countries from 1985 to 2015 via panel methods. Long- and short-run coefficients and the causal relationship between the variables are important for G7 countries' energy policies and strategy. Cointegration among CO2 emissions, militarization, energy consumption and economic growth was determined by using panel Johansen and panel autoregressive distributed lag (PARDL) methods. Further, the panel trivariate causality test was applied and unidirectional causalities from militarization to CO2 emissions and from energy consumption to CO2 emissions were found. The evidence of bidirectional causality between per capita GDP and militarization, between per capita GDP and energy consumption, and between energy consumption and militarization was determined. The paper recommends that environmental and energy policies must recognize the differences in the relation between militarization, energy consumption and economic growth in order to maintain sustainable economic growth in the G7 countries.