The upcoming Paris climate negotiations will constitute a critical step in the ongoing international process to reduce global greenhouse gas (GHG) emissions. The question of whether the Paris outcome will be sufficiently ambitious to put the world on a path towards limiting global average warming to 2o C, as agreed in Cancun, can be answered now. It will not, because that target, while possibly useful as an aspirational goal, is not achievable, as the most recent report of Working Group III of the IPCC documented. What is clear, however, is that greater ambition is more easily realized when costs are low. Market-based mechanisms are an important element in the portfolio of actions that can lead to cost-effective solutions. Linkage — between and among market and non-market systems for reducing GHG emissions — is a closely-related key element.
In an article just published in Climate Policy, "Facilitating Linkage of Climate Policies through the Paris Outcome," my co-authors — Daniel Bodansky of Arizona State University, Seth Hoedl of Harvard Law School, and Gilbert Metcalf of Tufts University — and I examine how the Paris outcome, and more generally the ongoing climate negotiations, can allow for and advance linked systems.
In the Durban Platform for Enhanced Action, adopted by the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC) in 2011, the parties agreed to develop a "protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties," for adoption at COP-21 in December, 2015, in Paris. It is likely that the Paris outcome will reflect a hybrid climate policy architecture — one that combines top-down elements, such as for monitoring, reporting, and verification (MRV), with bottom-up elements, including "Intended Nationally Determined Contributions" (INDCs), describing what a country intends to do to reduce emissions, based on domestic political feasibility and other factors. This outcome will be embodied in a core agreement, which likely will be legally binding, as well as ancillary instruments such as annexes, national schedules, and COP decisions.
The ability to link regional, national, and sub-national climate policies will be essential to enhancing the cost-effectiveness of such a system — and thus the likelihood of achieving significant global emissions reductions. By "linkage", we mean formal recognition by a GHG mitigation program in one jurisdiction (a regional, national, or sub-national government) of emission reductions undertaken in another jurisdiction for the purposes of complying with the first jurisdiction's requirements.
First Necessity for Paris: Do No Harm
The minimum requirement for the Paris agreement in regard to linkage is to do no harm. Silence on linkage could possibly accomplish that. But any provisions in the agreement that would require nations to achieve their respective INDCs exclusively within their own borders — a constraint that has been favored by the ALBA countries — would, in effect, prohibit not only international carbon markets but any sort of meaningful linkage (and would thereby greatly drive up costs).
Common Definitions of Key Terms
If linkage is to play a significant role in a hybrid international policy architecture, then several categories of design elements merit serious consideration for inclusion in the Paris outcome, either directly or by establishing a process for subsequent international negotiations. In general, effective linkage requires common definitions of key terms, including particularly the units to be used for compliance purposes. This will be particularly important for links between heterogeneous systems, and it is an area where a model rule could be particularly helpful (more about this below).
Registries and Tracking
Linkage requires registries and tracking mechanisms, whether the systems being linked are homogeneous or heterogeneous. Indeed, a key role for the top-down part of a hybrid architecture that allows for international linkage of national policy instruments will be the tracking, reporting, and recording of allowance unit transactions.
International compliance units would make the functioning of an international transaction log more straightforward and reduce the administrative burden of reconciling international registries with national registries. Minimum standards for approving and measuring offsets may be important. Market oversight and monitoring may increase confidence in the system, although in some cases, national and international institutions that can provide oversight already exist and may need only relatively minor additional capacity to assume these functions.
Too Much of a Good Thing Can be Bad
Including detailed linkage rules in the core agreement is not desirable as this could make it difficult for rules to evolve in light of experience. Instead, minimum standards to ensure environmental integrity should be elaborated in COP decisions, or by other means; for example, the COP could establish minimum requirements for national monitoring, reporting, and verification (MRV), registries, and crediting mechanisms.
In terms of linkage, the function of the core agreement might be confined to articulating general principles relating to environmental integrity, while also authorizing the COP or another organization to develop more detailed rules. Whatever minimum standards are adopted, oversight of compliance will be important to ensure the integrity both of the Paris outcome and of linked national systems.
The Utility of Default or Model Rules
Many elements of GHG linkage can be addressed through default or model rules from which nations are free to deviate at their discretion. Rules that may benefit from this approach are typically concerned with the details of linking two regulatory systems. For example, nations interested in linking their cap-and-trade systems would have to consider rules for market coverage, cost containment, banking and borrowing, compliance periods, allocation methods, and the treatment of new emitters and emitter closures. Additional rules may be needed for linking of heterogeneous systems.
Developing uniform rules to address all of these issues is unrealistic. Instead, a degree of harmonization could be achieved through default rules that facilitate linkage by providing a common framework for nations to use when developing their own linkage agreements. Although there is no need for the core agreement itself to elaborate harmonized linkage rules, it might authorize the COP to develop default linkage rules that nations can use in negotiating bilateral linkage agreements.
Less is More
In our Climate Policy article, Dan Bodansky, Seth Hoedl, Gib Metcalf, and I conclude that the most valuable outcome of Paris regarding linkage might simply be the inclusion in the core agreement of an explicit statement that parties may transfer portions of their INDCs to other parties and that these transferred units may be used by the transferees to implement their INDCs. Such a statement would help provide certainty both to governments and private market participants. This minimalist approach will allow diverse forms of linkage to arise, among what will inevitably be highly heterogeneous INDCs, thereby advancing the dual objectives of cost effectiveness and environmental integrity in the international climate policy regime.