![SEVENTH ASSESSMENT CYCLE
Working Group I – The Physical Science Basis
Extremes in line with AR6 ; but lots of new information
For mitigation:
“[…] By the end of the century,
scenarios with very low and low
GHG emissions would strongly
limit the change of several CIDs,
such as the increases in the
frequency of extreme sea level
events, heavy precipitation and
pluvial flooding, and exceedance
of dangerous heat thresholds,
while limiting the number of
regions where such
exceedances occur, relative to
higher GHG emissions scenarios
(high confidence). […]”
WG1 SPM, D2.4](https://image.slidesharecdn.com/ipccwg1atunfccccop284dec2023-231204150911-6c968503/85/Challenges-for-WG1-5-320.jpg)
![SEVENTH ASSESSMENT CYCLE
Working Group I – The Physical Science Basis
- Fate of carbon sinks due to land
degradation and climate change, and
related consequences on the remaining
carbon budget, CH4 emissions from
wetlands [remaining carbon budgets]
- Managed water cycle in a changing
climate, links between resource, use and
climate [water management & adaptation]
- Overshoot CMIP scenarios, and
CDR/Climate intervention
Knowledge gaps and emerging topics (examples)
• 2. Complex topics with policy relevance](https://image.slidesharecdn.com/ipccwg1atunfccccop284dec2023-231204150911-6c968503/85/Challenges-for-WG1-6-320.jpg)
Challenges for WG1
- 1. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis Challenges for WG1 WG1 Co-Chairs vision Robert Vautard, senior CNRS scientist Institut Pierre-Simon Laplace Xiaoye Zhang, Member of Chinese Academy of Engineering (CAE)
- 2. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis What can AR7 WG1 do after such a comprehensive AR6?
- 3. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis 1. Vision = crossing between what the community plans and what the governments need 2. - More integration across WGs 3. - Solutions-oriented products 4. - More packed and focused reports 5. - Less workload for authors and TSUs From lessons learned , knowledge gaps and Kigali WCRP
- 4. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis Since AR6, many, many more extremes and impacts Philip et al., 2022 Maximum yearly temperature British Columbia Humid heat : 4-day average daily maximum Heat Index during April, 2023, WWA, 2023
- 5. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis Extremes in line with AR6 ; but lots of new information For mitigation: “[…] By the end of the century, scenarios with very low and low GHG emissions would strongly limit the change of several CIDs, such as the increases in the frequency of extreme sea level events, heavy precipitation and pluvial flooding, and exceedance of dangerous heat thresholds, while limiting the number of regions where such exceedances occur, relative to higher GHG emissions scenarios (high confidence). […]” WG1 SPM, D2.4
- 6. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis - Fate of carbon sinks due to land degradation and climate change, and related consequences on the remaining carbon budget, CH4 emissions from wetlands [remaining carbon budgets] - Managed water cycle in a changing climate, links between resource, use and climate [water management & adaptation] - Overshoot CMIP scenarios, and CDR/Climate intervention Knowledge gaps and emerging topics (examples) • 2. Complex topics with policy relevance
- 7. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis - - Explain recent record-shattering, compound regional events, global events - - Better identify critical regional thresholds & global warming levels for tipping points, or climate drivers of ecosystems or social systems tipping points - - Explain regional model / observations differences in trends and variability - - Regional information to impacts Mechanisms and Impacts of Earth System Tipping elements, Wang et al., 2023 Knowledge gaps and emerging topics expectations • 1. Global AND regional information for mitigation and adaptation policies
- 8. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis Interfaces and discussion points (from WG1) REGIONAL CLIMATE INFORMATION ATLAS CMIP SCENARIOS & WARMING LEVELS CARBON WATER WG3 WG2 WG1
- 9. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis Emulator Warming levels WG1 ESM WCRP-CIMP New Scenarios Scientific Links With WGs WG1 WG2 WG3 Wait WG1 CIMP7 then Hope WG3-WCRP New Scenarios calibrate GST Wait WG1 Altas 2028 A shorter and more focused AR report will increase policy relevance and readability and give less work to authors A synchronization of WG1 with other WGs would better serve the needs for adaptation and mitigation assessment; WG1 could even start after WG3 (accommodating WG2/3 requests to the WG1 assessment) Even synthesis report should start first with scoping, or at least three working groups scoping together IPCC AR? IPCC SR?
- 10. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis • - Inclusion of gray literature and consider indigenous knowledge • - Enhanced inclusivity • - Including practitioners in scoping activities • - Carbon footprint • - Use of AI Other considerations
- 11. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis • “The choice and actions decided in this decade will have impacts now and for thousands of years (high confidence)” AR6 SYR, SPM, C.1 It is key to bring relevant information along the cycle Consider diversified products Timeliness of information
- 12. SEVENTH ASSESSMENT CYCLE Working Group I – The Physical Science Basis Thank you for your attention