近二十年前，《京都议定书》以具有法律约束力的方式为发达国家分配了减排目标。尽管表面上看起来装有“牙齿”，但京都模式脱离各国国内政治现实的弊端也逐渐显现。尤其是，这一“自上而下”的气候治理方式在主要排放国国内遭遇重重阻力：美国国会从未核准该议定书，加拿大也于2011年宣布退出。2009年哥本哈根气候大会之后，国际气候制度的构建方式已经呈现出明显变化，逐渐演进为以国家自主决定贡献（INDC）为特征的“自下而上”模式。然而，这一新发展对于国际社会开展应对气候变化合作、实现《公约》目标又带来了诸多新的挑战。

从自上而下到自下而上

《公约》及其《议定书》所搭建起来的国际气候制度框架，在发达国家与发展中国家之间竖了一道“防火墙”，两者责任、义务与权利显著不同。在实现《公约》目标的前提下，并根据各国达成共识的原则和规则，发达国家需要率先承担量化减排的气候承诺、并对发展中国家提供支持。而发展中国家则需要在得到发达国家相关支持的情况下、根据国家自身国情采取积极行动。《京都议定书》是自上而下模式推进国际气候制度构建的典型代表，这一模式一直延续到巴厘路线图所确立的“双轨谈判”时期。

双轨谈判是指，一方面，签署《京都议定书》的发达国家要在京都第二承诺的特设工作组中，谈判形成2012年以后的大幅度量化减排指标；另一方面，发展中国家和未签署《京都议定书》的发达国家（主要是指美国）则要在《联合国气候变化框架公约》下，在促进长期合作行动的特设工作组中谈判讨论进一步应对气候变化的措施。

自上而下模式往往法律约束力强，伴有较为严格的遵约机制，核算规则统一，且设有严格的测量、汇报、核证规则以确保透明度，但是各方达成行动共识的难度大、进度慢。受制于主要谈判缔约方（主要是发达国家）国内政治的制约，尤其伴随着全球政治经济与排放格局的发展，并且受到全球金融危机的影响，2009年的哥本哈根大会并未达成既定成果，自上而下模式的发展遭遇重大挫折。

在上述国际背景之下，国际气候合作呈现从“南北矛盾”向“大国博弈”和“大小之争”过渡的趋势。伞形国家集团所提出的“国家行动计划表”、“允诺加审评”的模式更好地契合了关键缔约方的国内政治，也更好地匹配了全球气候博弈的国际政治，逐渐获得了越来越多缔约方的认可。以此为基础，哥本哈根和坎昆两次会议酝酿和开启了公约缔约方共同做出减排允诺的新规则。2013年，华沙大会启动各国2020年后行动的INDC进程（即由各国自行提交的“自主贡献预案”），表明了以自下而上模式推进国际气候治理取得共识，也为2015年达成巴黎协议传递了重要的积极信号。新模式下，主要依靠各国自行提出各自的气候行动或目标，而不再通过艰苦谈判强制分配。汇总后的目标相应形成全球目标和共同行动。

相对于《公约》确立的原则与规则，以INDC进程为基础的“自下而上”模式更多考虑到各国的自身国情，是一种在各国国家利益的最大公约数基础上推进国际气候合作、寻求实现公约目标的机制。该模式往往具有“非强迫”和“非侵入”的特征，各国行动与目标也通常是多元化和多样性的，更有可能伴随合作性和促成性机制的构建，更易于吸引各方积极参与；但由于可能缺乏统一核算规则，缺乏对目标力度的指导和强制性要求，因此难以保证行动的整体力度，各国间的政治互信与积极互动也有待进一步增强。

被打破的“防火墙”

INDC进程是国际气候制度发展之路的重大转折，对全球气候治理会产生深远影响。综观各国提交的INDC文件，这些“自主贡献”五花八门、标准不一，且主要根据各国自身对其责任与能力的理解而自主提出，实际上已经打破了发达国家和发展中国家在公约及其议定书框架下关于各国责任、与责任相对应的承诺和行动的“防火墙”。INDC进程实质上是对共同但有区别的责任原则、各自能力原则、各自国情及其对应的“不对称承诺”在公约框架之下的新的再平衡。

这一“自下而上”的进程引发了国家承诺与行动的本质变化。共同但有区别的责任原则和公平原则是国际气候治理制度的核心基石。该原则将发达国家历史上的排放责任与应尽义务，与发展中国家未来的发展诉求与排放空间需要协调起来，将发达国家的技术、资金优势，与发展中国家亟待提高的能力以及全球应对气候变化的整体需要联系起来，最终以“二分法”和附件区分的形式，实现各国共同但有区别地承担“不对称承诺”。

然而在当前的INDC进程中，不管是发达国家还是发展中国家都共同地、自主地、不分先后地、甚至是在不论是否得到理应获得支持的情况下，在同一个谈判轨道中提出各自的目标与行动，且这样的承诺还有可能逐步面临统一的法律约束力与透明度要求。这一发展趋势，对于发展中国家公约义务的未来发展产生新的、额外的压力。在“防火墙”岌岌可危的情况下，如何处理好气候责任的平衡，避免气候责任的大国逃避责任与公约义务，是国际气候制度未来所面临的重大挑战。

另一方面，根据缔约方提交的INDC文件，各国的责任、承诺与行动均以各国“差异自表”的方式来体现。由此，各国开展气候行动的法律基础，从对于气候责任的担当，转向了更多取决于国家自身能力和行动意愿。这一发展趋势，是以实力为基础的大国政治博弈和关键国家国内政治的产物。它绕开了以升温目标和排放空间为基础的多边气候规则的科学性、公平性和有效性，使气候责任的大国得以摆脱自上而下的碳排放预算束缚。事实上，这种发展容易成为众多缔约方、尤其是发达国家逃避自身责任与义务的跳船平台，也难以有力、有效、公平地控制住全球排放的趋势。

不仅如此，目前发达国家的INDC文件以减缓为基本内容，不包括适应、资金、技术、能力建设以及行动与支持的透明度等要素，本质是对其公约下所需承担义务的规避，实质上使得INDC进程无法反映国际气候制度的所有核心要素，不利于达成全面、平衡、可持续实施的新协议。《公约》对于减缓与适应的共同关注，以及对于气候行动的力度、潜力、甚至是为发展中国家行动提供支持的安排，不仅是对于长期转型与当下应对的权衡，也是对发达国家与发展中国家在责任、权利、能力与发展阶段之间的权衡。当前“自下而上”的气候治理进程所体现出的有所偏颇的议题推进，未必有利于构建公平正义的国际气候制度，也难以真正提升全球行动力度，而全球行动力度则是实现《公约》目标的关键。

本文得到WWF中国气候与能源项目的支持，文中观点纰漏由作者自行承担，对此作者深表感谢。

邓梁春，世界自然基金会（WWF）项目顾问，主要研究方向为能源、环境与气候变化政策，国际气候治理制度。

The Paris climate change talks have just kicked-off, and there is general agreement amongst international society and the participants: a new global climate deal will be struck. That deal will be based on the UNFCCC, but different from the Kyoto Protocol in terms of degree of participation, strength of action taken, transparency and legal force.

Almost twenty years ago the Kyoto Protocol set legally binding emissions reduction targets for the developed nations. Despite appearing to have real force, it became increasingly apparent that Kyoto failed to take into account domestic political realities. As a result this “top-down” method of climate governance faced obstacle after obstacle in major carbon emitting nations: The US never ratified it; in 2011 Canada pulled out. After the Copenhagen talks in 2009 changes started to be seen in how international climate mechanisms were being put together, and the “bottom-up” INDC system took shape. But this development brings its own challenges for the world’s efforts to respond to climate change and implement the aims of the UNFCCC.

From top-down to bottom-up

The climate system put in place by the UNFCC and the Kyoto Protocol put a “firewall” in place between developed and developing nations: the two groups had different responsibilities, duties, and rights. The developed nations were to make earlier commitments to reduce emissions than developing nations, and to provide them with support. Meanwhile, on receiving that support the developing nations were to act on climate change in accordance with their national circumstances. The Kyoto Protocol was an example of a “top-down” approach to building a system of climate governance, an approach which continued until the “two-track negotiations” of the Bali Roadmap.

Those two-track negotiations meant the developed nation signatories to the Kyoto Protocol would set up special working groups during the second commitment period to set quantified targets for major emissions cuts post-2012; while developing nations and those developed nations not signed up to Kyoto (primarily the US) would discuss further climate change response measures in special working groups designed to foster long-term cooperation.

The top-down approach was legally binding and had strong enforcement mechanisms and a powerful measurement, reporting and verification system to ensure transparency. But reaching consensus was difficult and progress was slow. The domestic politics of key signatories (primarily the developed nations), particularly due to changes in the global political economy and the make-up of global emissions, and the impact of the financial crisis, meant no deal was reached in Copenhagen – a huge setback for the top-down approach.

Against this background we saw international climate interaction shift from north and south being in opposition, to a battle between the major powers, and between the large and small nations. The National Action Plans suggested by the Umbrella Group and the Commitment and Review approaches were found to better suit the needs of both international climate diplomacy and domestic politics. As such, these ideas became increasingly accepted and the Copenhagen and Cancun talks saw new rules for managing emissions commitments take shape.

In Warsaw in 2013 the INDC process was started – by 2020 each country would submit its own independently determined plans for emission cuts. There was now agreement on a new bottom-up approach, and the outlook for Paris was looking up. The new approach meant countries would put forward their own climate action plans and targets, rather than having this set through tortuous negotiations processes, and those plans and targets would, in the aggregate, represent joint action plans and global targets.

The INDC approach takes more account of national circumstances than the principles and rules embodied in the UNFCCC, representing an attempt to achieve the UNFCCC’s goals by relying on the individual national interest. It is voluntary and non-intrusive, and the action plans and targets it produces are diverse and varied, and may by accompanied with cooperative and facilitative mechanisms encouraging further participation. But a lack of a single verification method or a mechanism to encourage or require tougher targets mean it cannot ensure overall action with be powerful enough, and political trust and positive interactions still need to be strengthened.

Knocking down the firewall

The INDCs are a major change and will have a significant impact on global climate governance. The INDCs submitted are very varied and of different standards, and based on each country’s understanding of its own responsibilities and capabilities. In effect the UNFCCC’s distinction between the responsibilities of developed and developed nations, and the associated actions to be taken, has been broken down. The INDC process is in effect a rebalancing of the principles of common but differentiated responsibilities, respective capabilities, national circumstances and the corresponding “unequal commitments” of the UNFCC.

The new system changes the nature of national commitments and action. The principles of common but differentiated responsibility and fairness are the foundation of international climate governance, both coordinating the responsibility of the developed nations for their historical emissions with the need for future development and emissions of the developing world; and linking the technological and financial strengths of the developing nations with the urgent need for capacity building in developing nations and the overall global need to respond to climate change. This ultimately led to the “unequal commitments”, via the “dichotomy” and the annexes.

But in the current INDC process, both developed and developing nations are setting their own targets and action plans on one negotiating track: together, of their own accord, at the same time, and even without reference to whether or not support has been received. However, over time there will be calls for these targets to become legally binding and more transparent. That means new and unexpected pressure for developing nations. With the “firewall” at risk of collapse, there is a major new challenge for the global climate system: how to balance climate responsibilities and avoid major powers shirking their responsibilities under the UNFCCC.

Also, the INDCs allow each country to decide upon its own responsibilities, commitments and actions. This means the legal basis for national action is shifting from climate responsibility to respective capability and intent. That trend is the outcome of the realpolitik of major power diplomacy and the domestic politics of key countries. It bypasses the more scientific, fair and effective approach of a multilateral system based on limiting temperature rises, and allows major powers with climate responsibilities to avoid the limiting emission quotas of a top-down system. The change will make it easier for signatories, particularly the developed nations, to avoid their responsibilities and duties; and will make it more difficult to put in place strong, effective and fair controls on global emissions.

Moreover, the INDCs of developed nations are currently primarily about mitigation – adaptation, funding, technology and capacity building are missing, as are measures for transparency of actions taken and support given. This is in effect the avoidance of duties accepted under the UNFCCC, and means basic parts of the international climate system are missing from the INDC process. This will not help us reach a new powerful, balanced and sustainable agreement.

The UNFCCC’s coverage of both mitigation and adaptation, as well as the strength and potential for action of individual nations, and even the arrangements for support for action in developing countries, represented both a balancing of the need for long-term transitions and immediate response, and a consideration of the different responsibilities, duties, capabilities and stages of development of the developed and developing nations. The new bottom-up process has not advanced that agenda equally, which will not help build a fair and just system, or increase global efforts overall. And it is the strength of global efforts that will determine whether or not the aims of the UNFCC are achieved.

The author is grateful for support from WWF China’s Climate and Energy Programme for this article. The author is responsible for the views expressed in the article.