主要发达经济体从碳达峰到碳中和的路径及启示

随着气候变化影响加剧,全球气候治理进程加速,实现碳达峰已经成为全球气候行动的核心,各国也相继制定碳中和目标并开展行动。中国在第75届联合国大会一般性辩论上提出了碳达峰碳中和目标,部分已实现碳达峰的发达经济体也提出了各自的碳中和承诺。文中从“整体-阶段”及“焦点-公平”视角分析了欧盟和美国等主要发达经济体碳达峰的历程和特点,以及其碳中和目标和规划。研究发现,发达经济体在碳达峰过程中普遍经历了较长的爬坡期（58~136年）和平台期（4~20年),在碳达峰时,发达经济体的能源结构以油气为主,油气占一次能源消费比重为57%~77%,其人均排放量、历史累计排放以及人均GDP也都处于较高水平,在碳达峰前后总体处于经济与碳排放脱钩状态。各发达经济体的碳中和路径均以能源转型为重点,采用了多元化的政策工具,并且注重低碳和负碳技术的革新。根据发达经济体的政策展望,在实现碳中和时,均难以将绝对排放量降为零,都需要通过碳移除手段进行抵消。通过对比分析,发现中国的碳达峰和碳中和目标是具有雄心的气候承诺,相较其他发达经济体需要付出更大努力。建议运用全面综合的政策工具支撑碳中和目标的有效落实,加快中国的气候立法,在兼顾公正转型的同时推动能源结构调整,注重可再生能源和能效方面的新技术开发应用。     

A global comparison of carbon-water-food nexus based on dietary consumption

Exploring the environmental impact of dietary consumption has become increasingly important to understand the carbon-water-food nexus, vital to achieving UN sustainable development goals. However, the research on diet-based nexus assessment is still lacking. Here, we developed an Environmentally Extended Multi-Regional Input-Output (EE-MRIO) model with compiling a global MRIO table based on the latest Global Trade Analysis Project (GTAP) 10 database, where we specifically constructed a water withdrawal account and matched it to each economy at the sectoral level. The regional heterogeneity and synergy of carbon-water nexus affected by dietary patterns in nine countries was explored. The results show that: (1) Dietary consumption is the main use of water withdrawal for each country; Japan, the US, South Korea, and India have a high per capita dietary water footprint. Mainly due to consumption of processed rice, Japan has the highest per capita value of 488 M³/year, accounting for 63.4% of the total water footprint. (2) The total dietary carbon footprints in China, India, and the US are high, which is mainly caused by the high consumption of animal products (including dairy) either due to the large population (China, India) or animal-based diet (the US). Americans have the highest per capita dietary carbon footprint, reaching 755.4 kg/year, 2.76 times that of the global average. (3) Generally, imported/foreign footprints account for a greater share in dietary water and carbon footprints of developed countries with an animal-based diet. (4) In the nexus analysis, the US, Japan, and South Korea are key-nexus countries, vegetables, fruit and nuts, tobacco and beverages, and other food products are selected as key-nexus sectors with relatively high dietary water and carbon footprint. Furthermore, dietary consumption choices lead to different environmental impacts. It is particularly important to find a sustainable dietary route adapted to each country considering that heterogeneity and synergism exist in key-nexus sectors to achieve the relevant Sustainable Development Goals.     

Environmental and resource footprints in a global context: Europe’s structural deficit in resource endowments

The European Union (EU) has proposed in its Resource-efficiency roadmap a ‘dashboard of indicators’ consisting of four headline indicators for carbon, water, land and materials. The EU recognizes the need to use a consumption-based (or ‘footprint’) perspective to capture the global dimension of resources and their impacts. In this paper, we analyse how the EU’s footprints compare to those of other nations, to what extent the EU and other major economies of the world rely on embodied resource imports, and what the implications are for policy making based on this comparison. This study is the first comprehensive multi-indicator comparison of all four policy relevant indicators, and uses a single consistent global Multi-Regional Input Output (MRIO) database with a unique and high level of product detail across countries. We find that Europe is the only region in the world that relies on net embodied imports for all indicators considered. We further find that the powerful economies of China and others in the Asia-Pacific already dominate global resource consumption from a footprint perspective, while they still haven’t reached the prosperity of developed countries. Competition for resources is hence likely to increase, making Europe even more vulnerable. A hot spot analysis suggests that final consumption of food, transport and housing are priorities for reduction efforts along the life cycle. Further, countries with a similar Human Development Index can have very different footprints, pointing at societal organisation at macro-level as option for improvement. This points at options for countries for lowering their footprint, becoming less dependent on embodied imports, while maintaining a high quality of life.     

Comparing developing countries under potential carbon allocation schemes

To stabilise atmospheric greenhouse gas concentrations, all countries will eventually need to be included in the effort to limit climate change. This article explores what potential future greenhouse gas allocation schemes might mean for key developing countries. The need for development is widely acknowledged, but growth in non-Annex I country emissions means that such development may need to take a different path to business as usual. The national interests of developing countries in negotiating potential future commitments are shaped by basic characteristics, notably emissions (both annual and historical cumulative), economic growth and population. These factors in turn shape the acceptability of allocations based on ability to pay, emissions intensity, or emissions per capita.Results for six major developing countries (China, India, Brazil, South Africa, Argentina and Nigeria) show that the implications for developing countries differ widely. For example, ability to pay does not favour Argentina; a reduction based on emissions intensity is not appropriate for Brazil; and per capita allocations would be problematic for South Africa. It is difficult to conceive of a single allocation scheme that would be appropriate for all developing countries. This points to the need for differentiation between developing countries in terms of any potential future commitments.     

Comparing developing countries under potential carbon allocation schemes

Abstract

To stabilise atmospheric greenhouse gas concentrations, all countries will eventually need to be included in the effort to limit climate change. This article explores what potential future greenhouse gas allocation schemes might mean for key developing countries. The need for development is widely acknowledged, but growth in non-Annex I country emissions means that such development may need to take a different path to business as usual. The national interests of developing countries in negotiating potential future commitments are shaped by basic characteristics, notably emissions (both annual and historical cumulative), economic growth and population. These factors in turn shape the acceptability of allocations based on ability to pay, emissions intensity, or emissions per capita.

Results for six major developing countries (China, India, Brazil, South Africa, Argentina and Nigeria) show that the implications for developing countries differ widely. For example, ability to pay does not favour Argentina; a reduction based on emissions intensity is not appropriate for Brazil; and per capita allocations would be problematic for South Africa. It is difficult to conceive of a single allocation scheme that would be appropriate for all developing countries. This points to the need for differentiation between developing countries in terms of any potential future commitments.     

Dividing climate change: global warming in the Indian mass media

Much research has now been conducted into the representation of climate change in the media. Specifically, the communication of climate change from scientists and policy-makers to the public via the mass media has been a subject of major interest because of its implications for creating national variation in public understanding of a global environmental issue. However, to date, no study has assessed the situation in India. As one of the major emerging economies, and so one of the major greenhouse gas emitters, India is a key actor in the climate change story. This study analyses the four major, national circulation English-language newspapers to quantify and qualify the frames through which climate change is represented in India. The results strongly contrast with previous studies from developed countries; by framing climate change along a ‘risk-responsibility divide’, the Indian national press set up a strongly nationalistic position on climate change that divides the issue along both developmental and postcolonial lines.     

Managing carbon-intensive materials in a decarbonizing world without a global price on carbon

Emissions from the production of iron and steel could constitute a significant share of a 2°C global emissions budget (around 19% under the IEA 2DS scenario). They need to be reduced, and this could be difficult under nationally based climate policy approaches. We compare a new set of nationally based modelling (the Deep Decarbonization Pathways Project) with best practice and technical limit benchmarks for iron and steel and cement emissions. We find that 2050 emissions from iron and steel and cement production represent an average 0.28?tCO₂ per capita in nationally based modelling results, very close to the technical limit benchmark of 0.21?tCO₂ per capita, and over 2.5 times lower than the best practice benchmark of 0.72?tCO₂ per capita. This suggests that national projections may be overly optimistic about achievable emissions reductions in the absence of global carbon pricing and an international research and development effort to develop low emissions technologies for emissions-intensive products. We also find that equal per capita emissions targets, often the basis of proposals for how global emissions budgets should be allocated, would be inadequate without global emissions trading. These results show that a nationally based global climate policy framework, as has been confirmed in the Paris Agreement, could lead to risks of overshooting global emissions targets for some countries and carbon leakage. Tailored approaches such as border taxes, sectoral emissions trading or carbon taxes, and consumption-based carbon pricing can help, but each faces difficulties. Ultimately, global efforts are needed to improve technology and material efficiency in emissions-intensive commodities manufacturing and use. Those efforts could be supported by technology standards and a globally coordinated R&D effort, and strengthened by the adoption of global emissions budgets for emissions-intensive traded goods.

Policy relevance

This article presents new empirical findings on global iron and steel and cement production in a low-carbon world economy, demonstrates the risks associated with a nationally based global climate policy framework as has been confirmed in the Paris Agreement, and analyses policy options to deal with those risks.     

‘Great Powers’ in climate politics

The concept of ‘Great Powers’ extends well beyond its nineteenth century origins to current business in, for example, the EU, the UN Security Council, and the World Trade Organisation (WTO). Such core groups can be crucial to finding agreement in complex and fractured negotiations. Climate change was not initially seen as an issue for the Great Power-type architecture. The problem was of universal concern, requiring universal involvement. Moreover, climate's natural great powers (the EU, the US, China, Japan, Russia, Brazil, India, and Canada) split into three antagonistic camps: the EU pressing for sharp emissions reductions; the US, with the other developed powers, much more cautious; and China, India, and Brazil determined that action should be confined to the developed world. These divisions contributed hugely to the ineffectiveness of both the 1992 Rio convention and the 1997 Kyoto Protocol. In addition, as non-Organisation for Economic Co-operation and Development (OECD; particularly Chinese) emissions fast outgrew OECD emissions, their exclusion from any constraint became visibly untenable. So, from 2005 on, the Great Powers began to meet more closely in what became the Major Economies Forum. That cooperation contributed significantly to the 2009 Copenhagen Accord. The climate problem is of course far from being solved, but maintaining Great Power cooperation will be crucial to further progress.     

United States non-cooperation and the Paris agreement

In June 2017, the Trump administration decided to withdraw the US from the Paris Agreement, a landmark climate agreement adopted in 2015 by 195 nations. The exit of the US has not just raised concern that the US will miss its domestic emission reduction targets, but also that other parties to the Paris Agreement might backtrack on their initial pledges regarding emission reductions or financial contributions. Here we assess the magnitude of the threat that US non-cooperation poses to the Paris Agreement from an international relations perspective. We argue that US non-cooperation does not fundamentally alter US emissions, which are unlikely to rise even in the absence of new federal climate policies. Nor does it undermine nationally determined contributions under pledge and review, as the Paris Agreement has introduced a new logic of domestically driven climate policies and the cost of low-carbon technologies keeps falling. However, US non-participation in raising climate finance could raise high barriers to global climate cooperation in the future. Political strategies to mitigate these threats include direct engagement by climate leaders such as the European Union with key emerging economies, notably China and India, and domestic climate policies that furnish benefits to traditional opponents of ambitious climate policy.

Key policy insights

• US non-cooperation need not be a major threat to pledge and review under the Paris Agreement.

• US non-cooperation is a serious threat to climate finance.

• Deeper engagement with emerging economies offers new opportunities for global climate policy.

     

The scale and drivers of carbon footprints in households,cities and regions across India

The carbon footprint (CF) has emerged as an important yardstick to understand the total contribution of countries, sectors and individuals to climate change. In contrast to conventional emissions accounting which captures only territorial or local production activities, the CF includes the emissions imposed by consumption across global supply chains for goods and services. Recent interest has grown in the application of CF assessment for municipalities owing to their large contribution to global carbon emissions and the limited coverage of existing data to monitor their climate pledges. By linking household-level consumer surveys to a global supply chain database, spatially-explicit CF assessment is possible at a district and household scale. To date, such technique has exposed otherwise unforeseen differences in consumer carbon footprints in developed countries. Within this study we calculate and compare the household carbon footprints 623 districts in India, based on micro consumption data from 203,313 households and explain their variation by economic, cultural and demographic factors. We show the eradication of extreme poverty does not conflict with ambitious climate change mitigation in India. However, our analysis suggests CF reduction policies within India need to target high-expenditure households which are responsible for nearly seven times the carbon emissions than low-expenditure households (living on $1.9 consumption a day). These vast disparities between the carbon footprint of citizens in India highlights the need to differentiate individual responsibilities for climate change in national and global climate policy.     

Effective,efficient or equitable: using allowance allocations to mitigate emissions leakage

The European Union (EU), the US and Australia have each adopted, or are considering, free allocations to emissions-intensive, trade-exposed industries (EITEIs) in order to minimize emissions leakage and industrial offshoring resulting from climate policy. Differences in the design of these schemes, including how a country defines eligible EITEIs, the scale of allocation and the method of distribution, all have the potential to affect the outcomes of the programmes. In crafting their EITEI allocation formulas, policymakers in each country must balance three important priorities – the economic efficiency of the cap and trade programme, an equitable distribution of the programme's allowances and the effectiveness of the allocations in addressing leakage and competitiveness concerns. These three priorities provide a useful framework for considering the tradeoffs inherent in designing allocation schemes for EITEIs. Through this lens, policy approaches taken by the EU, US and Australia are evaluated with respect to four important questions of allocation policy design: the definition of EITEIs, the costs to be covered, the methodology for distributing allowances and the duration of free allocation.     

Time to act now? Assessing the costs of delaying climate measures and benefits of early action

This paper compares the results of the three state of the art climate-energy-economy models IMACLIM-R, ReMIND-R, and WITCH to assess the costs of climate change mitigation in scenarios in which the implementation of a global climate agreement is delayed or major emitters decide to participate in the agreement at a later stage only. We find that for stabilizing atmospheric GHG concentrations at 450?ppm CO₂-only, postponing a global agreement to 2020 raises global mitigation costs by at least about half and a delay to 2030 renders ambitious climate targets infeasible to achieve. In the standard policy scenario??in which allocation of emission permits is aimed at equal per-capita levels in the year 2050??regions with above average emissions (such as the EU and the US alongside the rest of Annex-I countries) incur lower mitigation costs by taking early action, even if mitigation efforts in the rest of the world experience a delay. However, regions with low per-capita emissions which are net exporters of emission permits (such as India) can possibly benefit from higher future carbon prices resulting from a delay. We illustrate the economic mechanism behind these observations and analyze how (1) lock-in of carbon intensive infrastructure, (2) differences in global carbon prices, and (3) changes in reduction commitments resulting from delayed action influence mitigation costs.     

Seizing policy windows: Policy Influence of climate advocacy coalitions in Brazil,China, and India, 2000–2015

What drives the development of climate policy? Brazil, China, and India have all changed their climate policies since 2000, and single-case analyses of climate policymaking have found that all three countries have had climate coalitions working to promote climate policies. To what extent have such advocacy coalitions been able to influence national policies for climate-change mitigation, and what can explain this? Employing a new approach that combines the advocacy coalition framework (ACF) with insights from comparative environmental politics and the literature on policy windows, this paper identifies why external parameters like political economy and institutional structures are crucial for explaining the climate advocacy coalitions’ ability to seize policy windows and influence policy development. We find that the coalitions adjust their policy strategies to the influence-opportunity structures in each political context—resulting in confrontation in Brazil, cooperation in China, and a complementary role in India.     

Great-power politics,order transition,and climate governance: insights from international relations theory

The complex politics of climate change cannot be properly understood without reference to deeper geopolitical trends in the wider international system. Chief among these is the growing resurgence of ‘great-power politics’ between China and the US, along with failures of socialization and enmeshment into global governance structures in relation to these two powers. Traditional theoretical frameworks have failed to adequately account for these developments. Nonetheless, this current great-power contestation is at the core of an order transition that has prevented the large-scale institutional redesign required to remove deadlocks in existing global governance structures, including climate governance. Examples from the 2009 Copenhagen Climate Change Conference provide ample evidence for these claims. The slow progress of the climate change negotiations are due not just to the politics of the issue itself, but to the absence of a new political bargain on material power structures, normative beliefs, and the management of the order amongst the great powers. Without such a grand political bargain, which could be promoted through a forum of major economies whose wide-ranging remit would go beyond single issues, the climate change regime is only ever likely to progress in a piecemeal fashion.

Policy relevance

Despite the achievements of the 2012 Doha Climate Change Conference, the climate negotiations are not on course to limit warming to 2 °C, and thereby avoid ‘dangerous’ climate change. Several factors have been invoked to account for such slow progress: notably, the nature of the climate change problem itself, the institutional structure of the climate regime, and lack of political will among key players. An alternative explanation is proposed such that the failure to seriously address climate change – as well as other global problems – reflects a resurgent meta-struggle between the ‘great powers’ of China and the US over the nature of the global order. Without such a broader understanding of the deeper dynamics underlying the stalemates of the climate change negotiations, there is little chance of turning those negotiations around.     

National contributions to climate change mitigation from agriculture: allocating a global target

Globally, agriculture and related land use change contributed about 17% of the world’s anthropogenic GHG emissions in 2010 (8.4 GtCO₂e yr^?1), making GHG mitigation in the agriculture sector critical to meeting the Paris Agreement’s 2°C goal. This article proposes a range of country-level targets for mitigation of agricultural emissions by allocating a global target according to five approaches to effort-sharing for climate change mitigation: responsibility, capability, equality, responsibility-capability-need and equal cumulative per capita emissions. Allocating mitigation targets according to responsibility for total historical emissions or capability to mitigate assigned large targets for agricultural emission reductions to North America, Europe and China. Targets based on responsibility for historical agricultural emissions resulted in a relatively even distribution of targets among countries and regions. Meanwhile, targets based on equal future agricultural emissions per capita or equal per capita cumulative emissions assigned very large mitigation targets to countries with large agricultural economies, while allowing some densely populated countries to increase agricultural emissions. There is no single ‘correct’ framework for allocating a global mitigation goal. Instead, using these approaches as a set provides a transparent, scientific basis for countries to inform and help assess the significance of their commitments to reducing emissions from the agriculture sector.

Key policy insights

• Meeting the Paris Agreement 2°C goal will require global mitigation of agricultural non-CO₂ emissions of approximately 1 GtCO₂e yr^?1 by 2030.

• Allocating this 1 GtCO₂e yr^?1 according to various effort-sharing approaches, it is found that countries will need to mitigate agricultural business-as-usual emissions in 2030 by a median of 10%. Targets vary widely with criteria used for allocation.

• The targets calculated here are in line with the ambition of the few countries (primarily in Africa) that included mitigation targets for the agriculture sector in their (Intended) Nationally Determined Contributions.

• For agriculture to contribute to meeting the 2°C or 1.5°C targets, countries will need to be ambitious in pursuing emission reductions. Technology development and transfer will be particularly important.

     

基于博弈模型的中美气候谈判策略模拟

中美在气候谈判中的共识和分歧已成为影响未来气候谈判走向的重要因素。基于效用和博弈理论,考虑温升幅度及其对GDP影响等因素的不确定性,以及气候变化相关投资对各国净现值效用的负面、正面和外溢影响,对中美气候谈判进行博弈策略模拟及敏感性分析。结果表明,中美气候谈判博弈存在先动劣势,且中美在非合作博弈下的气候变化投资远远无法实现全球2℃控温目标;在合作博弈情景下,为确保实现全球温升控制目标的合作框架的稳定和双赢,未来的气候制度框架需要关注对中国的技术、资金支持和补偿。     

Electricity regulation in the Chinese national emissions trading scheme (ETS): lessons for carbon leakage and linkage with the EU ETS

Carbon leakage is central to the discussion on how to mitigate climate change. The current carbon leakage literature focuses largely on industrial production, and less attention has been given to carbon leakage from the electricity sector (the largest source of carbon emissions in China). Moreover, very few studies have examined in detail electricity regulation in the Chinese national emissions trading system (which leads, for example, to double counting) or addressed its implications for potential linkage between the EU and Chinese emissions trading systems (ETSs). This article seeks to fill this gap by analysing the problem of ‘carbon leakage’ from the electricity sector under the China ETS. Specifically, a Law & Economics approach is applied to scrutinize legal documents on electricity/carbon regulation and examine the economic incentive structures of stakeholders in the inter-/intra-regional electricity markets. Two forms of ‘electricity carbon leakage’ are identified and further supported by legal evidence and practical cases. Moreover, the article assesses the environmental and economic implications for the EU of potential linkage between the world’s two largest ETSs. In response, policy suggestions are proposed to address electricity carbon leakage, differentiating leakage according to its sources.

Key policy insights

• Electricity carbon leakage in China remains a serious issue that has yet to receive sufficient attention.

• Such leakage arises from the current electricity/carbon regulatory framework in China and jeopardizes mitigation efforts.

• With the US retreat on climate efforts, evidence suggests that EU officials are looking to China and expect an expanded carbon market to reinforce EU global climate leadership.

• Given that the Chinese ETS will be twice the size of the EU ETS, a small amount of carbon leakage in China could have significant repercussions. Electricity carbon leakage should thus be considered in any future EU–China linking negotiations.

     

China’s rising influence on climate governance: Forging a path for the global South

China’s influence on climate governance has been steadily increasing since the adoption of the Paris Agreement on climate change in 2015. Much of this influence, this article argues, has come from China forging a path for climate adaptation and mitigation for the global South. This is having far-reaching consequences, the article further argues, for the politics of global climate governance. China’s discursive and diplomatic power in climate politics is growing as China builds alliances across the global South. China is leveraging this enhanced soft power to elevate the importance of adaptation in multilateral climate negotiations, advance a technocentric approach to climate mitigation, export its development model, and promote industrial-scale afforestation as a nature-based climate solution. China’s strategy is enhancing climate financing, technology transfers, renewable power, and adaptation infrastructure across the global South. To some extent, this is helping with a transition to a low-carbon world economy. Yet China’s leadership is also reinforcing incremental, technocratic, and growth-oriented solutions in global climate governance. These findings advance the understanding of China’s role in global environmental politics, especially its growing influence on climate governance in the global South.     

Tele-connecting local consumption to global land use

Globalization increases the interconnectedness of people and places around the world. In a connected world, goods and services consumed in one country are often produced in other countries and exchanged via international trade. Thus, local consumption is increasingly met by global supply chains oftentimes involving large geographical distances and leading to global environmental change. In this study, we connect local consumption to global land use through tracking global commodity and value chains via international trade flows. Using a global multiregional input–output model with sectoral detail allows for the accounting of land use attributed to “unusual” sectors – from a land use perspective – including services, machinery and equipment, and construction. Our results show how developed countries consume a large amount of goods and services from both domestic and international markets, and thus impose pressure not only on their domestic land resources, but also displace land in other countries, thus displacing other uses. For example, 33% of total U.S. land use for consumption purposes is displaced from other countries. This ratio becomes much larger for the EU (more than 50%) and Japan (92%). Our analysis shows that 47% of Brazilian and 88% of Argentinean cropland is used for consumption purposes outside of their territories, mainly in EU countries and China. In addition, consumers in rich countries tend to displace land by consuming non-agricultural products, such as services, clothing and household appliances, which account for more than 50% of their total land displacement. By contrast, for developing economies, such as African countries, the share of land use for non-agricultural products is much lower, with an average of 7%. The emerging economies and population giants, China and India, are likely to further increase their appetite for land from other countries, such as Africa, Russia and Latin America, to satisfy their own land needs driven by their fast economic growth and the needs and lifestyles of their growing populations.     

A Chinese commitment to commit: can it break the negotiation stall?

Preparatory talks to the next round of negotiations seem to indicate that a comprehensive agreement to mitigate climate change will not be easily attainable, despite the intentions of the US administration and the high expectations surrounding the Copenhagen meeting. One key reason is to what extent fast growing economies, and especially China, should take actions to reduce their growth of emissions. This paper argues that a turning point for international negotiations on climate change could be achieved if China were to agree on carbon obligations in the future. Results from modelling work suggest that the optimal investment behaviour is to anticipate the implementation of a climate policy by roughly 10 years, and that thus future commitments—if credible—could lead to significantly earlier steps towards carbon mitigation. If fast growing economies, and foremost China, believe in the long term objective of global stabilization of carbon concentrations, it might be economically rationale to sign on future targets, provided developed countries take on immediate action. Such a provision could be beneficial for both the developing and developed world.