France will again be welcoming the international climate community as it hosts, from March 13-16, 2018, the 47th session of the Intergovernmental Panel on Climate Change (IPCC). This event gives an opportunity to both celebrate the IPCC’s 30th birthday, and to reflect on its critical role for global climate policy.
A reinforced legitimacy
The World Meteorological Organization (WMO) and the United Nations Environment Program (UNEP) jointly created the Intergovernmental Panel on Climate Change (IPCC) in 1988. Its main task was initially to answer two questions: “is the Earth’s climate changing”?, and “why?”. Thirty years later, the IPCC efforts have permitted to provide clear and unambiguous answers to both: “yes, the Earth’s climate is changing, and human activities are largely responsible for this trend”.
Thanks to its production of Assessment Reports (AR) featuring peer-reviewed scientific research, the IPCC has played a decisive role in supporting the policy dynamics over this period. Its First AR (published in 1990) played a decisive role in the creation of the United Nations Framework Convention on Climate Change (UNFCCC), the main international institution aimed at responding to the challenges brought by climate change. Since then, regular updates of scientific knowledge in successive IPCC reports have pushed policymakers to take part in international efforts, supporting the adoption of the Kyoto Protocol (1997) and the recent Paris Agreement (2015).
A new mandate
So what is the role of the IPCC in 2018, given the new political landscape created by the Paris Agreement? The current context is marked by different types of news, facts and analyses about climate change. On the one hand, recent information describes temperature records in the North Pole, higher previsions in terms of sea-level rise due to the melting of ice caps in the Antarctica, increased risks of severe droughts in European cities, etc. And according to some analysts, the opportunity to meet the Paris Agreement’s objective of limiting global warming to +2°C in reference to pre-industrial levels is fading away. On the other hand, data suggests that greenhouse gas emissions have already started to peak in ~50 countries, due to the effective deployment of mitigation technologies and domestic policies. The IPCC is now playing a key role to help disentangle these facts and inform the international community’s response, following a major shift in its mandate in 2015. The COP21 decision indeed directly invited the IPCC to produce a special report on the +1.5°C climate stabilization objective, and the Paris Agreement introduces 5-yearly global stocktake on the implementation of the Agreement “in the light of the best available science”, for which IPCC is naturally meant to provide direct inputs.
This new mandate has led to a significant reorganization of the 6th Assessment cycle of the IPCC (2016-2023). In addition to the above mentioned Report on 1.5°C and the core product—the Assessment Report (AR6)—the 6th cycle will comprise two further special reports (on Ocean and Cryosphere, and on Land use, respectively) and a methodology report (on national greenhouse gas inventories). The timing of those reports has also been adjusted to align the release of key products with important political milestones on the intentional agenda—the 1.5°C Special Report in October 2018 ahead of the 2018 Facilitative Dialogue and the AR6 in 2021-2022 in the lead up to the 2023 Global Stocktake.
While it is up to the UNFCCC to maintain a constructive working atmosphere to ensure the successful adoption of the Paris implementation rules, the primary task of the IPCC is to provide the scientific arguments to frame the discussions among policymakers and stakeholders. The publication of the 1.5°C special report in October 2018 is the first milestone of this new IPCC cycle and will be critical to anchor the IPCC in its new mandate. This report is eagerly expected by scientists, policymakers, and civil society alike to steer the discussions at the next COP in Poland (Katowice) (COP24) in December this year, on how to achieve the ambitious climate goals set by the Paris Agreement.
We identify three major challenges for the AR6 cycle:
- First, the IPCC is to take stock of recent measurements of accelerated signs of climate change (e.g. on the melting of ice caps), which imply to re-assess AR5 projections. This new assessment is key to emphasize that climate mitigation and adaptation are no longer challenges for the future, but present concerns to act upon, all over the world. The IPCC needs to deliver a clear and straightforward message to the global community about the important risks from delayed action.
- Second, the progress and gaps in global and national mitigation efforts pave the way for an assessment of the state of progress towards the “well below 2°C/1.5°C”climate stabilization objective. This assessment should be conducted in the light of country-driven definition of objectives coupled with a long-term vision. Aligning short-term actions with long-term mitigation and adaptation targets is indeed both a challenge and the key to a successful transformation of all sectors of the economy to build a resilient and low-carbon world.
- Third, a clear understanding of the range of solutions being tested or deployed already is needed, for mitigation and adaptation as well as for investments and development finance The identification of the most effective levers for climate action should guide and support decision-makers on setting the right priorities for today and identify opportunities for action in the years ahead.
Addressing these three challenges will be essential to support the first global stocktake that will take place in 2023. The road will not be easy as the IPCC conclusions are likely to, as always, challenge diplomatic positions and alliances. But whatever the political, social and economic barriers ahead, the world undeniably needs an evidence-based understanding of climate change issues, from physical processes to impacts and potential responses. This is and will remain IPCC’s role. Happy birthday to you, IPCC, and may your next thirty years witness the advent of a low-carbon and resilient world!
 As for the report on 1.5°C, Henri Waisman, senior researcher at IDDRI and coordinator of the Deep Decarbonization Pathways Project (DDPP), has been appointed lead author of Chapter 5 on sustainable development, poverty eradication, and reducing inequalities. Concerning the special report on oceans and cryosphere, Jean-Pierre Gattuso, Director of Research at CNRS and associate researcher at IDDRI, has been appointed coordinating lead author of Chapter 1 on the framing and context of the report, and Alexandre Magnan, senior researcher at IDDRI, has been appointed lead author of Chapter 4 on sea level rise and implications for low lying islands, coasts and communities.