Climate change mitigation calls for the limitation and reduction of greenhouse gas (GHG) emissions across all sectors. However, limiting GHG emissions from aviation has proven to be problematic for technical reasons (e.g., lack of low-carbon alternatives) as well as legal reasons (e.g., international aviation does not readily fall within any one state's jurisdiction). Relevant initiatives have followed two streams. At the international level, the International Civil Aviation Organization (ICAO) has adopted technical standards and, more recently, a market-based mechanism to limit emissions from international civil aviation. In parallel, states have adopted their own policies and measures to regulate emissions from both domestic and international aviation, ranging from tax and technical standards to traffic management and infrastructural development. While much of the literature on climate change mitigation in the aviation sector has focused on international efforts, this article reveals the importance of understanding the tensions and complementarities of the two streams.

The Supreme Court of the Netherlands construed the state’s positive human rights obligations as requiring a 25 per cent reduction of its greenhouse gas emissions by 2020 compared with 1990 levels. This article explores how judges can decide the level of state effort required to mitigate climate change. To date, judges have predominantly approached this issue by seeking to identify an elusive benchmark, either by deduction from global objectives or induction from state conduct. This article shows that the judicial assessment of a state’s requisite efforts inevitably relies on equity infra legem. Acknowledging this, judges could learn from the international courts’ experience with establishing clarity in the midst of vague legal rules.

With its narrow focus on price-based policies and ‘explicit’ carbon prices, the EU carbon border adjustment mechanism (CBAM) aims to prevent carbon leakage by ensuring that imported products ‘bear’ the same exact economic costs ‘borne’ by EU products. The proposed US border carbon adjustment (BCA) and the recent proposal for a global steel and aluminium arrangement (GSAA), by contrast, reflect a broader focus on environmental equivalence and recourse to punitive or quasi-punitive remedies. All recently proposed carbon border measures suffer from specific limitations. Further, albeit to a different extent, they are all associated with problematic aspects in terms of WTO law compatibility. This research note enquires whether the GSAA could be fine-tuned at the regulatory design stage in such a way as to provide an environmentally effective and WTO law compatible way forward. The analysis illustrates that recourse to an installation-based approach, emission limit values and product standards would achieve these goals. Nonetheless, the implementation of this ambitious strategy would be fraught with political obstacles.

Carbon taxes are likely to play a key role in meeting greenhouse gas emission targets that are consistent with the Paris Agreement. In this article, we assess the macroeconomic effects of a carbon tax on the global economy, paying particular attention to the terms-of-trade implications for importers and exporters of fossil fuels. We use a modified version of the National Institute’s Global Econometric Model, NiGEM. In the stylized scenarios, all countries and regions impose a permanent and uniform carbon tax immediately. Our simulations show that demand for fossil fuels falls substantially in response to the tax, global (pre-tax) prices of fossil fuels decline, and the tax can raise substantial revenue for the government. The overall impact on GDP growth and inflation in each country depends on the fossil fuel intensity of output, the net losses/gains in terms of trade and the macroeconomic policy reaction.

Protecting tropical forests from deforestation is important for mitigating both biodiversity loss and anthropogenic climate change. In Amazonia, a common approach to protected area (PA) impact studies has been to investigate differences among broad PA categories, such as strictly protected, sustainable use and indigenous areas, yet these may be insufficient for the management of PAs at local scales. We used a matching method to compare impacts and carbon emissions avoided during 2011–2016 of individual PAs in the state of Acre (Brazil). Although most PAs had a positive impact and effectively prevented forest loss, we observed substantial variation among them in terms of impacts, pressures and emissions during our study period. The impacts varied from 3.6% avoided to 15.6% induced forest loss compared to expected levels of deforestation estimated for each PA using the matching method. All but a few PAs helped avoid substantial amounts of emissions. Our results emphasize the need for more PA impact studies that compare multiple PAs at the individual level in Amazonia and beyond.

The agriculture and food sectors contribute significantly to greenhouse gas emissions. About 15 percent of food-related carbon emissions are channeled through restaurants. Using a contingent valuation (CV) method with double-bounded dichotomous choice (DBDC) questions, this article investigates U.S. consumers’ willingness to pay (WTP) for an optional restaurant surcharge in support of carbon emission reduction programs. The mean estimated WTP for a surcharge is 6.05 percent of an average restaurant check, while the median WTP is 3.64 percent. Our results show that individuals have a higher WTP when the surcharge is automatically added to restaurant checks. We also find that an information nudge—a short climate change script—significantly increases WTP. Additionally, our results demonstrate that there is heterogeneity in treatment effects across consumers’ age, environmental awareness, and economic views. Our findings suggest that a surcharge program could transfer a meaningful amount of the agricultural carbon reduction burden to consumers that farmers currently shoulder.

This paper analyses the role that companion policies have had in the reduction of emissions regulated by the EU Emissions Trading System (EU ETS) and the related policy interactions, with a view to identifying relevant insights for China's forthcoming Emissions Trading System (ETS). The investigation rests on: (a) the observation of the EU's and China's ETSs and policy mixes; (b) economic theory concerning companion policies and ETS design; and (c) empirical ex-post evidence from the EU ETS. Three main conclusions emerge from the analysis. First, China's ETS, while not imposing a fixed cap on emissions, will not be immune to waterbed effects of companion policies. Second, the European experience stresses the importance of making explicit the objectives pursued by companion policies, and of balancing policies for innovation and policies for adoption of low-carbon technologies. Third, in the presence of a major market surplus, only permanent adjustments to allowance supply can be effective in raising prices.

Finding the ways that work to deliver the innovation needed should be given parity of esteem with getting the prices right as a focus of the economics profession and policy systems. Learn from experience as regards carbon pricing and carbon-reducing innovation; insights from the latter coming mainly from the US, China and Europe; demographically relatively small countries – Denmark (wind) and Australia (solar PV) – can make outsize contributions. A carbon price ceiling is too low to drive innovation; generating carbon-reducing innovation requires that it be explicitly recognized as a priority, and nurtured accordingly: identify the priority area(s) where innovation at scale will be necessary to make progress; baseline the elements of the innovation ecosystem which are already in place, and the gaps that need to be filled. Key elements include institutions and incentives that promote innovation, a research and enterprise community that make it happen, and a supportive public.

Expansion of cultivated lands and field management impacts greenhouse gas (GHG) emissions from agriculture soils. Soils naturally cycle GHGs and can be sources or sinks depending on physical and chemical properties affected by cultivation and management status. We looked at how cultivation history influences GHG emissions from subtropical soils. We measured CO2, N2O, and CH4 fluxes, and soil properties from newly converted and continuously cultivated lands during the summer rainy season in calcareous soils from south Florida. Newly converted soils had more soil organic matter (OM), more moisture, higher porosity, and lower bulk density, leading to more GHG emissions compared to historically cultivated soils. Although more nutrients make newly converted lands more desirable for cultivation, conversion of new areas for agriculture was shown to release more GHGs than cultivated lands. Our data suggest that GHG emissions from agricultural soils may decrease over time with continued cultivation.

The distribution of household carbon footprints is largely unequal within and across countries. Here, we explore household-level consumption data to illustrate the distribution of carbon footprints and consumption within 26 European Union countries, regions and social groups. The analysis further sheds light on the relationships between carbon footprints and socially desirable outcomes such as income, equality, education, nutrition, sanitation, employment and adequate living conditions.

This paper examines whether green Official Development Aid (ODA) has a significant role in mitigating carbon emissions in recipient countries, and if institutional quality matters for the effectiveness of green ODA. For 86 green ODA recipient countries over the period 2003–2014, we explore the nexus between green ODA, institutions and carbon emissions. By using a two-step system generalized method of moment (GMM), we find that green ODA overall has no direct association with the mitigation of carbon emissions. However, when institutional quality indices are included, we found a significant effect of institutional quality on the effectiveness of green ODA. In general, green ODA is associated with higher carbon emissions in countries with poor institutions. In particular, green ODA is effective in mitigating carbon emissions when channeled to countries that enjoy higher economic freedom as well as more freedom from corruption. Results are mixed for the rule of law.

The climate crisis requires nations to achieve human well-being with low national levels of carbon emissions. Countries vary from one another dramatically in how effectively they convert resources into well-being, and some nations with low levels of emissions have relatively high objective and subjective well-being. We identify urgent research and policy agendas for four groups of countries with either low or high emissions and well-being indicators. Least studied are those with low well-being and high emissions. Understanding social and political barriers to switching from high-carbon to lower-carbon modes of production and consumption, and ways to overcome them, will be fundamental.