Use of scenarios in IPCC’s 6th assessment cycle (AR6)

Organizers: Jan Fuglestvedt (CICERO), Ramon Pichs-Madruga (CIEM)


The AR6 is a highly interlinked assessment cycle, with three Special Reports overseen by the three IPCC Working Groups (WGs), as well as the preparation of the three WG reports and the Synthesis Report. A key feature of the AR6 is the enhanced inter-linkages across the assessment on a range of cross-cutting topics. Meeting these assessment needs will require coordination to ensure consistency across the AR6 reports and to facilitate the preparation of the Synthesis Report. Climate change scenarios are a key overarching topic that will need such an enhanced integrated approach across the WGs to ensure their consistent and comprehensive assessment and use in the AR6.

The session will present key messages from the assessment of scenarios in the IPCC Special Report on Global Warming of 1.5ºC (SR1.5) and discuss lessons learned from scenario work in both IPCC 5th Assessment (AR5) and the SR1.5. Consistency and integration of scenarios across disciplines and key developments, challenges and their use in the context of climate change assessments will be addressed. The presentations will focus on connecting the various modeling approaches and spatial/temporal scales in the scenario assessment processes including methodological challenges, main gaps and their implications.

Core set of questions to be addressed:

a) What was the role of scenarios in producing key conclusions in SR1.5, and what benefits or drawbacks were there to their use? What lessons from that experience are useful for other IPCC products in the AR6 cycle and beyond?

b) How can scenarios be used most effectively in AR6, particularly to promote consistency and synthesis of findings across chapters and WGs? What are the key challenges?

c) What is the suitability of the current SSP-RCP scenarios framework for IPCC assessments, or would additions/modifications help?

d) How are the various spatial/temporal scales captured by the scenario assessment processes, and what are the potential options for improving the regional perspective?

e) What are the main opportunities, synergies, challenges and gaps for an integrative scenario approach in assessing environment and development trends in the context of the Agenda 2030 and the SDGs?

The workshop will have invited speakers from different backgrounds representing different perspectives and parts of the scenario work within the AR6. The talks will address how scenarios can help integrating work on interaction among emissions, climate, risks and development pathways, on both near-term and long-term time scales, regional climate changes and impacts and costs and benefits of mitigation and adaptation in the context of sustainable development. The workshop will build on the sessions of the Scenarios Forum to discuss how the latest progress in scenarios research, development and their use may underpin the integrated assessment of scenarios within the AR6. The workshop will end with a panel discussion with the invited speakers.

Submissions of abstracts to this session are not being accepted since all panel members will be invited, in order to reflect the specific perspectives described above.