Blog Post

Question 4 for COP 21: Mitigation

In this blog series, Questions for COP 21, we are posing several questions that should be considered before—and after—the negotiations. Here we address mitigation: Can an agreement based on cycles to review and periodically renew voluntary climate pledges deliver ambitious, long-term global emissions reductions?

Since Copenhagen, discussions have moved away from a top-down, compliance-oriented approach to one based on bottom-up nationally determined efforts. The new Paris agreement also seems likely to establish an ongoing cyclic process to review and periodically renew commitments, perhaps at five-year intervals. While such cycles would provide an ongoing process, indeed an expectation, to examine and enhance commitments, just as with top-down approaches, process alone cannot force action on unwilling nations.

Analyses of the aggregate effect of the Intended Nationally Determined Contributions (INDCs) demonstrate that current proposals do not place the world on track to limit warming to less than 2 (or 1.5) °C.  Moreover, it will become increasingly challenging for nations to get on track as the effort becomes larger and the time shorter with each passing year. Three possible developments could improve the prospects of achieving long-term objectives:

  1. If science establishes that climate sensitivity lies at the lower end of current estimates, then there will be more time to act, requiring less near-term effort;
  2. If innovation leads to an availability of lower-cost, low-carbon technologies that can also be rapidly deployed, then nations will be more willing to agree to stronger action;
  3. If concerns over climate impacts grow, then nations presumably will be more willing to take action.

Many critical aspects of the process remain unclear, for example, timing. Suppose the initial period lasts through 2025. When would nations submit proposals for 2030? Some suggest 2020 (ten years ahead, and only 5 years from now), others 2025. Both present challenges to the development and timely availability of relevant information and to institutional linkages to supply official information (even in OECD nations, official national inventories are typically not available for a given year until ~18 months later).

Ambitious global outcomes for mitigation will only occur if all major emitting nations participate and act. For this to occur reliably, effective transparency processes will be essential both to build confidence in the Paris Agreement and to inform cycles of review and renewal. In addition to timely information on national plans and progress, the process will also require external input on other key aspects, especially concerning evolving science, advances in technology, and experience with policies. Likely sources could include national agencies, the International Energy Agency, the Organisation for Economic Co-operation and Development (OECD), the Organization of Petroleum Exporting Countries (OPEC), the United Nations Environment Programme (UNEP), the Intergovernmental Panel on Climate Change (IPCC), academia, and others. Several nations have called on IPCC to inform deliberations. However, current products and procedures seem unsuited to the needs, and IPCC would need to become far more nimble.

Transformational change to a low-carbon society will require decades of long-term effort; for success, maintaining continuity will be essential but challenging. Five-year cycles and 10-year objectives will inevitably interact with political change from domestic elections and unforeseeable events. Already in this first year of INDC submissions, governments have changed in ways that may materially affect proposals and overall portfolios. To be successful, the process will need to navigate political realities when intervals may be a decade or more between pledges and outcomes. Indeed the 2 °C goal may become a flashpoint for controversy in the next few years. Surely the process will need to find ways to avoid the sort of tensions that led to the breakdown of the Kyoto Protocol.

In any event, establishing durable cycles to review and renew commitments appears to be another positive innovation; one that may allow more attention to substance and less to process going forward. We hope that thoughtful input from a variety of perspectives can help to shape an effective process and determine information needs and vehicles to inform the approach.

Read more posts in the series, Questions for COP 21: