Catalyzing mitigation ambition under the Paris Agreement: elements for an effective Global Stocktake

The Global Stocktake (GST) takes a central role within the architecture of the Paris Agreement, with many hoping that it will become a catalyst for increased mitigation ambition. This paper outlines four governance functions for an ideal GST: pacemaker, ensurer of accountability, driver of ambition and provider of guidance and signal. The GST can set the pace of progress by stimulating and synchronizing policy processes across governance levels. It can ensure accountability of Parties through transparency and public information sharing. Ambition can be enhanced through benchmarks for action and transformative learning. By reiterating and refining the long term visions, it can echo and amplify the guidance and signal provided by the Paris Agreement. The paper further outlines preconditions for the effective performance of these functions. Process-related conditions include: a public appraisal of inputs; a facilitative format that can develop specific recommendations; high-level endorsement to amplify the message and effectively inform national climate policy agendas; and an appropriate schedule, especially with respect to the transparency framework. Underlying information provided by Parties complemented with other (scientific) sources needs to enable benchmark setting for collective climate action, to allow for transparent assessments of the state of emissions and progress of a low-carbon transformation. The information also needs to be politically relevant and concrete enough to trigger enhancement of ambition. We conclude that meeting these conditions would enable an ideal GST and maximize its catalytic effect.

Key policy insights

• The functional argument developed in this article may inspire a purposeful design of the GST as its modalities and procedures are currently being negotiated.

• The analytical framework provided serves as a benchmark against which to assess the GST's modalities and procedures.

• Gaps and blind spots in the official GST can and should be addressed by processes external to the climate regime in academia and civil society.

     

The global climate action summit: increasing ambition during turbulent times

In September 2018, leaders in climate action within and outside the U.S. will convene in San Francisco for the Global Climate Action Summit. They plan to demonstrate strong ongoing commitment to exceeding the goals set out in the Paris Agreement, despite U.S. federal opposition under President Trump, and to spur greater ambition among subnational governments and the private sector. Now that the Trump Administration is working to undo the progress made under President Obama, it is more important than ever that states and cities, as well as the private sector, redouble their efforts. Since the 2016 election, many U.S. states have demonstrated leadership by establishing ever-more ambitious clean energy and electric vehicle targets through legislation and executive action; by pushing back on the Trump Administration in public forums and in the courts; and by banding together to realise greater effectiveness through collective action. The commitment of leading states, cities, and businesses alone will not be enough to achieve the rapid reductions needed to keep planetary warming to 1.5 degrees C in the absence of U.S. federal efforts. But coming after a summer of extreme weather events, the Summit represents a critical opportunity to re-energise constituencies, highlight the need for urgent and ambitious action, and bring climate change to the forefront of policy conversations across the U.S. and beyond.

Key policy insights

• The reversal of U.S. ambitious clean energy and transportation policy, including replacing the Clean Power Plan, freezing fuel standards, and withdrawing from the Paris Agreement, have created a gap at the federal level under President Trump that will be difficult – but perhaps not impossible – to fill with subnational action.

• States, local governments, and the private sector have shown a strengthened commitment to combating climate change and to the goals set out in the Paris Agreement through more ambitious legislative and executive targets, and regional initiatives like RGGI and cross-jurisdictional zero emissions vehicle programmes.

• The Global Climate Action Summit in September 2018 is a pivotal moment to energise a broader coalition within and outside the U.S. towards catalysing the level of ambition needed to exceed goals set out in the Paris Agreement.

     

Resilience through interlinkage: the green climate fund and climate finance governance

The Green Climate Fund (GCF) is a significant and potentially innovative addition to UNFCCC frameworks for mobilizing increased finance for climate change mitigation and adaptation. Yet the GCF faces challenges of operationalization not only as a relatively new international fund but also as a result of US President Trump’s announcement that the United States would withdraw from the Paris Agreement. Consequently the GCF faces a major reduction in actual funding contributions and also governance challenges at the levels of its Board and the UNFCCC Conference of the Parties (COP), to which it is ultimately accountable. This article analyzes these challenges with reference to the GCF’s internal regulations and its agreements with third parties to demonstrate how exploiting design features of the GCF could strengthen its resilience in the face of such challenges. These features include linkages with UNFCCC constituted bodies, particularly the Technology Mechanism, and enhanced engagement with non-Party stakeholders, especially through its Private Sector Facility. The article posits that deepening GCF interlinkages would increase both the coherence of climate finance governance and the GCF’s ability to contribute to ambitious climate action in uncertain times.

Key policy insights

• The Trump Administration’s purported withdrawal from the Paris Agreement creates challenges for the GCF operating model in three key domains: capitalization, governance and guidance.

• Two emerging innovations could prove crucial in GCF resilience to fulfil its role in Paris Agreement implementation: (1) interlinkages with other UNFCCC bodies, especially the Technology Mechanism; and (2) engagement with non-Party stakeholders, especially private sector actors such as large US investors and financiers.

• There is also an emerging soft role for the GCF as interlocutor between policy-makers and non-Party actors to help bridge the communication divide that often plagues cross-sectoral interactions.

• This role could develop through: (a) the GCF tripartite interface between the Private Sector Facility, Accredited Entities and National Designated Authorities; and (b) strengthened collaborations between the UNFCCC Technical and Financial Mechanisms.

     

国家自主贡献更新进展、特征及其对全球气候治理的影响

国家自主贡献(NDC)是《巴黎协定》最核心的制度,体现了全球气候治理模式从"自上而下"到"自下而上"的变迁.文中对截至2021年7月1日92个缔约方通报或更新的NDC进行了比较分析,识别出7种更新方式:提高量化减排目标数字、调整减排目标类型和覆盖范围、增加适应目标和政策、增加2050年减排愿景、主动适用NDC信息和核算...     

Including animal to plant protein shifts in climate change mitigation policy: a proposed three-step strategy

Strong and rapid greenhouse gas (GHG) emission reductions, far beyond those currently committed to, are required to meet the goals of the Paris Agreement. This allows no sector to maintain business as usual practices, while application of the precautionary principle requires avoiding a reliance on negative emission technologies. Animal to plant-sourced protein shifts offer substantial potential for GHG emission reductions. Unabated, the livestock sector could take between 37% and 49% of the GHG budget allowable under the 2°C and 1.5°C targets, respectively, by 2030. Inaction in the livestock sector would require substantial GHG reductions, far beyond what are planned or realistic, from other sectors. This outlook article outlines why animal to plant-sourced protein shifts should be taken up by the Conference of the Parties (COP), and how they could feature as part of countries’ mitigation commitments under their updated Nationally Determined Contributions (NDCs) to be adopted from 2020 onwards. The proposed framework includes an acknowledgment of ‘peak livestock’, followed by targets for large and rapid reductions in livestock numbers based on a combined ‘worst first’ and ‘best available food’ approach. Adequate support, including climate finance, is needed to facilitate countries in implementing animal to plant-sourced protein shifts.

Key policy insights

• Given the livestock sector’s significant contribution to global GHG emissions and methane dominance, animal to plant protein shifts make a necessary contribution to meeting the Paris temperature goals and reducing warming in the short term, while providing a suite of co-benefits.

• Without action, the livestock sector could take between 37% and 49% of the GHG budget allowable under the 2°C and 1.5°C targets, respectively, by 2030.

• Failure to implement animal to plant protein shifts increases the risk of exceeding temperate goals; requires additional GHG reductions from other sectors; and increases reliance on negative emissions technologies.

• COP 24 is an opportunity to bring animal to plant protein shifts to the climate mitigation table.

• Revised NDCs from 2020 should include animal to plant protein shifts, starting with a declaration of ‘peak livestock’, followed by a ‘worst first’ replacement approach, guided by ‘best available food’.

     

A discursive cartography of nationally determined contributions to the Paris climate agreement

The 2015 Paris Agreement was adopted in a geopolitical context that is very different from the post-Cold War era when the Climate Convention was negotiated. This new global climate deal responds to a more fragmented and multipolar world signified by the rise of major economies in the South. This paper examines the geopolitical landscape in which the Paris Agreement is enacted and implemented. We conduct a discursive analysis of the Nationally Determined Contributions submitted by parties to the Paris Agreement. We ask what policy discourses emerge in these national climate plans, which states cluster around them and how they compare to UNFCCC annex, geographical location, income group, and negotiation coalitions. Our findings suggest that liberal environmentalism retains a strong hold over the political imagination in the post-Paris landscape. However, we see points of diffraction and tensions that might give rise to conflict. While liberal environmentalism is only challenged in Nationally Determined Contributions from the global South, we conclude that conventional geopolitical patterns only partly explain the formation of discourse coalitions. In the Paris Agreement’s implementation stage discursive struggles are likely to become increasingly prominent. Discourse analysis facilitates understanding of disagreements on the Paris rulebook and the global stocktake.     

Regional GHG reduction targets based on effort sharing: a comparison of studies

Over 40 studies that analyse future GHG emissions allowances or reduction targets for different regions based on a wide range of effort-sharing approaches and long-term concentration stabilization levels are compared. This updates previous work undertaken for the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Regional reduction targets differ significantly for each effort-sharing approach. For example, in the Organisation for Economic Co-operation and Development (OECD) 1990 region, new proposals that emphasize the equity principles of responsibility, capability, and need, and those based on equal cumulative per capita emissions (carbon budgets), lead to relatively stringent emissions reduction targets. In order to reach a low concentration stabilization level of 450?ppm CO₂e, the allowances under all effort sharing approaches in OECD1990 for 2030 would be approximately half of the emissions of 2010 with a large range, roughly two-thirds in the Economies in Transition (EIT), roughly at the 2010 emissions level or slightly below in Asia, slightly above the 2010 level in the Middle East and Africa and well below the 2010 level in Latin America. For 2050, allowances in OECD1990 and EIT would be a fraction of today's emissions, approximately half of 2010 emission levels in Asia, and possibly less than half of the 2010 level in Latin America.

Policy relevance

The concept of equity and the stringency of future national GHG reduction targets are at the heart of the current debate on the new international climate change agreement to be adopted in 2015. Policy insights gained from an analysis of over 40 studies, which have quantitatively analysed the proposed GHG reduction targets, are presented. It is found that the outcome of effort-sharing approaches is often largely determined by the way the equity principle is implemented and that the distributional impacts of such approaches can be significantly different depending on the criteria used, the stabilization level and shape of the global emissions pathway. However, the current literature only covers a small proportion of the possible allocation approaches. There should thus be an in-depth modelling comparison to ensure consistency and comparability of results and inform decision making regarding the reduction of GHG emissions.     

Additionality revisited: guarding the integrity of market mechanisms under the Paris Agreement

ABSTRACT

The Paris Agreement requires mitigation contributions from all Parties. Therefore, the determination of additionality of activities under the market mechanisms of its Article 6 will need to be revisited. This paper provides recommendations on how to operationalize additionality under Article 6. We first review generic definitions of additionality and current approaches for testing of additionality before discussing under which conditions additionality testing of specific activities or policies is still necessary under the new context of the Paris Agreement, that is, in order to prevent increases of global emissions. We argue that the possibility of ‘hot air’ generation under nationally-determined contributions (NDCs) requires an independent check of the NDC’s ambition. If the NDC of the transferring country does contain ‘hot air’, or if the transferred emission reductions are not covered by the NDC, a dedicated additionality test should be required. While additionality tests of projects and programmes could continue to be done through investment analysis, for policy instruments new approaches are required. They should be differentiated according to type of policy instrument. For regulation, we suggest calculating the resulting pay-back period for technology users. If the regulation generates investments exceeding a payback period threshold, it could be deemed additional. Similarly, carbon pricing policies that generate a carbon price exceeding a threshold could qualify; for trading schemes an absence of over-allocation needs to be shown. The threshold should be differentiated according to country categories and rise over time.

Key policy insights

• Without additionality testing, market mechanisms under the Paris Agreements might lead to an international diffusion of ‘hot air’. To avoid this, an independent assessment of NDC ambition is in order. Otherwise, activities under the mechanisms need to undergo specific additionality tests.

• Additionality testing of projects and programmes should build on the experience developed under the Kyoto Protocol mechanisms.

• Bold approaches are needed for assessing additionality of policies. To avoid cumbersome assessment of all activities triggered by such policies, highly aggregated approaches are suggested, ranging from payback period thresholds for technologies mandated by regulation to minimum price levels triggered by carbon pricing policies. Over time, the stringency of threshold values should increase.

     

Ocean acidification and climate change: synergies and challenges of addressing both under the UNFCCC

Ocean acidification and climate change are linked by their common driver: CO₂. Climate change is the consequence of a range of GHG emissions, but ocean acidification on a global scale is caused solely by increased concentrations of atmospheric CO₂. Reducing CO₂ emissions is therefore the most effective way to mitigate ocean acidification. Acting to prevent further ocean acidification by reducing CO₂ emissions will also provide simultaneous benefits by alleviating future climate change. Although it is possible that reducing CO₂ emissions to a level low enough to address ocean acidification will simultaneously address climate change, the reverse is unfortunately not necessarily true. Despite the ocean's integral role in the climate system and the potentially wide-ranging impacts on marine life and humans, the problem of ocean acidification is largely absent from most policy discussions pertaining to CO₂ emissions. The linkages between ocean acidification, climate change and the United Nations Framework Convention on Climate Change (UNFCCC) are identified and possible scenarios for developing common solutions to reduce and adapt to ocean acidification and climate change are offered. Areas where the UNFCCC is currently lacking capacity to effectively tackle rising ocean acidity are also highlighted.     

Estimating baselines for climate change for less developed countries: the case of the Sahel

Abstract

The UN Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol provide mechanisms for assisting less developed countries that are adversely affected by climate change. Such assistance would need a baseline, which ideally would set a precise date for specific impacts of climate change. This article presents the results of statistical tests that we carried out and, for the African region of the Sahel, finds that for precipitation (affecting food supply), impacts due to climate change can be ‘dated’ to the year 1967, when precipitation fell drastically, affecting the local food supply. Such a statistically robust benchmark would be useful to the Subsidiary Body for Scientific and Technological Advice (SBSTA) of the UNFCCC. The method illustrates how other baselines may be established for the important work of the SBSTA.     

The challenges of monitoring national climate policy: learning lessons from the EU

One of the most central and novel features of the new climate governance architecture emerging from the 2015 Paris Agreement is the transparency framework committing countries to provide, inter alia, regular progress reports on national pledges to address climate change. Many countries will rely on public policies to turn their pledges into action. This article focuses on the EU’s experience with monitoring national climate policies in order to understand the challenges that are likely to arise as the Paris Agreement is implemented around the world. To do so, the research employs – for the first time – comparative empirical data submitted by states to the EU’s monitoring system. Our findings reveal how the EU’s predominantly technical interpretation of four international reporting quality criteria – an approach borrowed from reporting on GHG fluxes – has constrained knowledge production and stymied debate on the performance of individual climate policies. Key obstacles to more in-depth reporting include not only political concerns over reporting burdens and costs, but also struggles over who determines the nature of climate policy monitoring, the perceived usefulness of reporting information, and the political control that policy knowledge inevitably generates. Given the post-Paris drive to achieve greater transparency, the EU’s experience offers a sobering reminder of the political and technical challenges associated with climate policy monitoring, challenges that are likely to bedevil the Paris Agreement for decades to come.

Policy relevance

The 2009 Copenhagen summit ushered in a more bottom-up system of international climate governance. Such systems typically depend on strong monitoring approaches to assess past performance and estimate future national contributions over time. This article shows why decision makers at multiple governance levels should pay serious attention to empirical data on the experiences and challenges that have emerged around monitoring in the EU, a self-proclaimed climate leader. The analysis highlights key political and administrative challenges that policy makers will likely encounter in implementing climate policy monitoring and ensuring transparency in the spirit of the Paris Agreement.     

Governing people on the move in a warming world: Framing climate change migration and the UNFCCC Task Force on Displacement

Different ways of framing the nexus between climate change and migration have been advanced in academic, advocacy and policy circles. Some understand it as a state-security issue, some take a protection (or human security) approach and yet others portray migration as an adaptation or climate risk management strategy. Yet we have little insight into how these different understandings of the ‘problem’ of climate change-related migration are beginning to shape the emergence of global governance in the climate regime. Through a focus on the UNFCCC Task Force on Displacement we argue that these different framings of climate change migration shape how actors understand the appropriate role of the TFD, including the substantive scope of its mandate; its operational priorities; the nature of its outputs and where it should be situated in the institutional architecture. We show that understanding the different framings of the nexus between climate change and migration – and how these framings are contested within the UNFCCC – can help to account for institutional development in this area of climate governance.     

Experimentalist governance in climate finance: the case of REDD+ in Brazil

One of the most significant impacts of the United Nations Framework Convention on Climate Change (UNFCCC) has been the establishment of a participatory process for Reducing Emissions from Deforestation and Forest Degradation (REDD+). We analyse the case of Brazil, the country whose land-use emissions from deforestation and forest degradation have declined the most. Through semi-structured interviews with 29 country policy experts – analysed in full text around 7 categories of activities that existing literature identifies as central elements of an effective governance system – we find weak links between the international REDD+ system and what actually happens on the ground inside Brazil. The greatest weaknesses are rooted in the absence of any formal learning system, which prevents higher-level efforts from obtaining useful feedback from lower-level entities responsible for implementation. Analytically our approach is rooted in the idea of ‘experimentalist governance’ in which local policy experiments map the space of what is possible and effective with transformative land policy. These experiments provide information to broader international initiatives on how local implementation shapes the ability and strategy to reach global goals. The Brazilian experience suggests that even when international funding is substantial, local implementation remains a weak link. REDD+ reforms should focus less on the total amount of money being spent and much more on how those funds are used to generate useful local policy experiments and learning.

Key policy insights

• A nascent system of experimentalist governance to implement REDD+ is taking shape in Brazil. However, the potential for experimentalism to improve policy reforms within Brazil is far from realized;

• Experimentalist problem-solving approaches could have a big impact on REDD+ with stronger incentives to promote experimentation and learning from experience;

• Reforms to REDD+ incentive schemes should focus less on the total amount of money being spent and more on whether those funds are actually generating experimental learning and policy improvement – in Brazil and in other countries struggling with similar challenges.

     

Achievability of the Paris Agreement targets in the EU: demand-side reduction potentials in a carbon budget perspective

Limiting global warming to ‘well below’ 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase even further to 1.5°C is an integral part of the 2015 Paris Agreement. To achieve these aims, cumulative global carbon emissions after 2016 should not exceed 940 – 390?Gt of CO₂ (for the 2°C target) and 167 – ?48?Gt of CO₂ (for the 1.5°C target) by the end of the century. This paper analyses the EU’s cumulative carbon emissions in different models and scenarios (global models, EU-focused models and national carbon mitigation scenarios). Due to the higher reductions in energy use and carbon intensity of the end-use sectors in the national scenarios, we identify an additional mitigation potential of 26–37 Gt cumulative CO₂ emissions up to 2050 compared to what is currently included in global or EU scenarios. These additional reductions could help to both reduce the need for carbon dioxide removals and bring cumulative emissions in global and EU scenarios in line with a fairness-based domestic EU budget for a 2°C target, while still remaining way above the budget for 1.5°C.

Key policy insights

• Models used for policy advice such as global integrated assessment models or EU models fail to consider certain mitigation potential available at the level of sectors.

• Global and EU models assume significant levels of CO₂ emission reductions from carbon capture and storage to reach the 1.5°C target but also to reach the 2°C target.

• Global and EU model scenarios are not compatible with a fair domestic EU share in the global carbon budget either for 2°C or for 1.5°C.

• Integrating additional sectoral mitigation potential from detailed national models can help bring down cumulative emissions in global and EU models to a level comparable to a fairness-based domestic EU share compatible with the 2°C target, but not the 1.5°C aspiration.

     

Confronting the challenge of integrated assessment of climate adaptation: a conceptual framework

Key limitations of integrated assessment models (IAMs) are their highly stylized and aggregated representation of climate damages and associated economic responses, as well as the omission of specific investments related to climate change adaptation. This paper proposes a framework for modeling climate impacts and adaptation that clarifies the relevant research issues and provides a template for making improvements. We identify five desirable characteristics of an ideal integrated assessment modeling platform, which we elaborate into a conceptual model that distinguishes three different classes of adaptation-related activities. Based on these elements we specify an impacts- and adaptation-centric IAM, whose optimality conditions are used to highlight the types of functional relationships necessary for realistic representations of adaptation-related decisions, the specific mechanisms by which these responses can be incorporated into IAMs, and the ways in which the inclusion of adaptation is likely to affect the simulations’ results.     

Constructed peer groups and path dependence in international organizations: The case of the international climate change negotiations

International organizations sometimes institutionalize country groupings by specifying differentiated commitments that may, in turn, affect negotiation dynamics. Drawing on incentive-based and socialization arguments, we develop a “constructed peer group” hypothesis suggesting that by creating these groups those organizations may actually construct new lines of confrontation over and above the substance-based disagreements existing between countries. This generates a particular type of path dependence, rendering broad-based international agreements more difficult in the future.We analyze this question at the example of the United Nations Framework Convention on Climate Change's increasingly politicized split between Annex I and non-Annex I countries. Using a self-coded dataset of country oral statements during the negotiations between December 2007 and December 2009 we assess whether Annex I membership influences a country's stance toward other countries’ arguments, while controlling for country characteristics that may drive their preferences and the affiliation to Annex I. We find that the split between Annex I and non-Annex I has indeed influenced negotiation behavior and amplified the divide between developing and industrialized countries in the climate negotiations.     

Intellectual property rights and the transfer of climate change technologies: issues,challenges, and way forward

The role of intellectual property rights (IPRs) in the development and transfer of climate change technologies has been a contentious issue in negotiations under the United Nations Framework Convention on Climate Change (UNFCCC). Irreconcilable differences seem to oppose those who believe IPRs are an inherent barrier to the transfer of climate change technologies and those who argue they are an essential incentive to innovation. After providing an overview of the polarized debate on this issue, this article reviews the existing literature and empirical evidence and looks into some practical initiatives and recent developments. Finally, it seeks to identify a way forward that could help overcome the current stalemate in international deliberations by suggesting a number of parameters to structure the discussion on this complex issue.     

A global stocktake of the Paris pledges: Implications for energy systems and economy

The United Nations-led international climate change negotiations in Paris in December 2015 (COP21) trigger and enhance climate action across the globe. This paper presents a model-based assessment of the Paris Agreement. In particular, we assess the mitigation policies implied by the Intended Nationally Determined Contributions (INDCs) put forward in the run-up to COP21 by individual member states and a policy that is likely to limit global warming to 2 °C above pre-industrial levels. We combine a technology-rich bottom-up energy system model with an economy-wide top-down CGE model to analyse the impact on greenhouse gas emissions, energy demand and supply, and the wider economic effects, including the implications for trade flows and employment levels. In addition, we illustrate how the gap between the Paris mitigation pledges and a pathway that is likely to restrict global warming to 2 °C can be bridged. Results indicate that energy demand reduction and a decarbonisation of the power sector are important contributors to overall emission reductions up to 2050. Further, the analysis shows that the Paris pledges lead to relatively small losses in GDP, indicating that global action to cut emissions is consistent with robust economic growth. The results for employment indicate a potential transition of jobs from energy-intensive to low-carbon, service oriented sectors.     

Muddling through with climate change targets: a multi-level governance perspective on the transport sector

The UK Climate Change Act 2008 commits to a reduction of 80% in national GHG emissions by 2050 compared to 1990 levels. This article explores what happens next where these top-level aspirations are expected to be turned into radical action. It does so through examination of the transport sector, which is a highly complex, fragmented, and multi-level delivery environment. The research draws on cases studies of four major cities with different governance structures within the two distinct, yet connected, national contexts of England and Scotland. It integrates a range of theoretical legacies, namely ‘muddling through’, multi-level governance, and positional analysis, to look across governmental layers and out to non-governmental actors at all levels. Underneath the 80% target, the framework for action remains unclear. Lower-tiered authorities report difficulties in acting in a more comprehensive or rapid manner than upper tiers of government, largely because of the potential costs involved and a significant resource dependency on national governments. Ambition is also tempered by conflicts with economic growth objectives and the difficulties in aligning the objectives of the myriad of public and private organizations that need to take action.     

Global impact of a climate treaty if the Human Development Index replaces GDP as a welfare proxy

This study explores the implications of shifting the narrative of climate policy evaluation from one of costs/benefits or economic growth to a message of improving social welfare. Focusing on the costs of mitigation and the associated impacts on gross domestic product (GDP) may translate into a widespread concern that a climate agreement will be very costly. This article considers the well-known Human Development Index (HDI) as an alternative criterion for judging the welfare effects of climate policy. We estimate what the maximum possible annual average increase in HDI welfare per tons of CO₂ would be within the carbon budget associated with limiting warming to 2°C over the period 2015–2050. Emission pathways are determined by a policy that allows the HDI of poor countries and their emissions to increase under a business-as-usual development path, while countries with a high HDI value (>0.8) have to restrain their emissions to ensure that the global temperature rise does not exceed 2°C. For comparison, the well-known multi-regional RICE model is used to assess GDP growth under the same climate change policy goals.

Policy relevance

This is the first study that shifts the narrative of climate policy evaluation from one of GDP growth to a message of improving social welfare, as captured by the HDI. This could make it easier for political leaders and climate negotiators to publicly commit themselves to ambitious carbon emission reduction goals, such as limiting global warming to 2°C, as in the (non-binding) agreement made at COP 21 in Paris in 2015. We find that if impacts are framed in terms of growth in HDI per t CO₂ emission per capita instead of in GDP, the HDI of poor countries and their emissions are allowed to increase under a business-as-usual development path, whereas countries with a high HDI (>0.8) must control emissions so that global temperature rise remains within 2°C. Importantly, a climate agreement is more attractive for rich countries under the HDI than the GDP frame. This is good news, as these countries have to make the major contribution to emissions reductions.