Transcription of 1 1. 2 2. Chapter 1: Framing and Context 3 4 Myles Allen ...
1 Approval Session Chapter 1 IPCC 1 1. 2 2. Chapter 1: Framing and Context 3. 4 Coordinating Lead Authors: Myles Allen (UK), Opha Pauline Dube (Botswana), William Solecki 5 (USA). 6. 7 Lead Authors: Fernando Arag n Durand (Mexico), Wolfgang Cramer (France/Germany), Stephen 8 Humphreys (UK/Ireland), Mikiko Kainuma (Japan), Jatin Kala (Australia), Natalie Mahowald (USA), 9 Yacob Mulugetta (UK/Ethiopia), Rosa Perez (Philippines), Morgan Wairiu (Solomon Islands), 10 Kirsten Zickfeld (Canada). 11. 12 Contributing Authors: Purnamita Dasgupta (India), Haile Eakin (USA), Bronwyn Hayward (New 13 Zealand), Diana Liverman (USA/UK), Richard Millar (UK), Graciela Raga (Argentina), Aur lien 14 Ribes (France), Mark Richardson (USA/UK), Maisa Rojas (Chile), Roland S f rian (France), Sonia 15 Seneviratne (Switzerland), Christopher Smith (UK), Will Steffen (Australia), Peter Thorne 16 (Ireland/UK).
2 17. 18 Review Editors: Ismail Elgizouli Idris (Sudan), Andreas Fischlin (Switzerland), Xuejie Gao (China). 19. 20 Chapter Scientist: Richard Millar (UK). 21. 22 Date of Draft: 4/06/18. 23. 24 Notes: TSU compiled version. Copy editing not done. 25. Do Not Cite, Quote or Distribute 1-1 Total pages: 61. Approval Session Chapter 1 IPCC 1 Table of Content 2. 3 Executive Summary .. 4. 4 Assessing the knowledge base for a C warmer world .. 7. 5 Box : The Anthropocene: Strengthening the global response to C global warming.
3 8. 6 Equity and a C warmer 9. 7 Eradication of 10. 8 Sustainable development and a C warmer world .. 11. 9 Understanding C: reference levels, probability, transience, overshoot, stabilization .. 12. 10 Working definitions of C and 2 C warming relative to pre-industrial levels .. 12. 11 Definition of global average temperature .. 12. 12 Choice of reference period .. 14. 13 Total versus human induced warming and warming rates .. 15. 14 Global versus regional and seasonal warming .. 16. 15 Definition of C-consistent pathways: probability, transience, stabilization and 16 overshoot.
4 17. 17 Pathways remaining below C .. 18. 18 Pathways temporarily exceeding C .. 19. 19 Impacts at C warming associated with different pathways: transience versus 20 stabilisation .. 19. 21 Cross- Chapter Box 1: Scenarios and Pathways .. 21. 22 Geophysical warming commitment .. 23. 23 Cross- Chapter Box 2: Measuring progress to net zero emissions combining long-lived and 24 short-lived climate forcers .. 26. 25 Impacts at C and beyond .. 28. 26 28. 27 Drivers of 29. 28 Uncertainty and non-linearity of 30. 29 Strengthening the global response.
5 31. 30 Classifying Response Options .. 31. 31 Governance, implementation and policies .. 32. 32 Cross- Chapter Box 3: Framing feasibility: Key concepts and conditions for limiting global 33 temperature increases to C .. 33. 34 Transformation, transformation pathways, and transition: evaluating trade-offs and 35 synergies between mitigation, adaptation and sustainable development 35. 36 Cross- Chapter Box 4: Sustainable Development and the Sustainable Development Goals .. 36. 37 Assessment frameworks and emerging methodologies that integrate climate change mitigation 38 and adaptation with sustainable development.
6 38. 39 Knowledge sources and evidence used in the report .. 38. 40 Assessment frameworks and methodologies .. 39. Do Not Cite, Quote or Distribute 1-2 Total pages: 61. Approval Session Chapter 1 IPCC 1 Confidence, uncertainty and risk .. 40. 2 Storyline of the report .. 41. 3 Frequently Asked Questions .. 43. 4 FAQ : Why are we talking about C? .. 43. 5 FAQ : How close are we to C? .. 45. 6 References .. 47. 7. Do Not Cite, Quote or Distribute 1-3 Total pages: 61. Approval Session Chapter 1 IPCC 1 Executive Summary 2.
7 3 This Chapter frames the Context , knowledge-base and assessment approaches used to understand the 4 impacts of C global warming above pre-industrial levels and related global greenhouse gas 5 emission pathways, building on the IPCC Fifth Assessment Report (AR5), in the Context of 6 strengthening the global response to the threat of climate change, sustainable development and efforts 7 to eradicate poverty. 8. 9 Human-induced warming reached approximately 1 C ( C likely range) above pre-industrial 10 levels in 2017, increasing at C ( C) per decade (high confidence).
8 Global warming is 11 defined in this report as an increase in combined surface air and sea surface temperatures averaged 12 over the globe and a 30-year period. Unless otherwise specified, warming is expressed relative to the 13 period 1850-1900, used as an approximation of pre-industrial temperatures in AR5. For periods 14 shorter than 30 years, warming refers to the estimated average temperature over the 30 years centered 15 on that shorter period, accounting for the impact of any temperature fluctuations or trend within those 16 30 years.
9 Accordingly, warming up to the decade 2006-2015 is assessed at C. 17 ( C likely range). Since 2000, the estimated level of human-induced warming has been equal to 18 the level of observed warming with a likely range of 20% accounting for uncertainty due to 19 contributions from solar and volcanic activity over the historical period (high confidence). { }. 20. 21 Warming greater than the global average has already been experienced in many regions and 22 seasons, with average warming over land higher than over the ocean (high confidence).
10 Most land 23 regions are experiencing greater warming than the global average, while most ocean regions are 24 warming at a slower rate. Depending on the temperature dataset considered, 20-40% of the global 25 human population live in regions that, by the decade 2006-2015, had already experienced warming of 26 more than C above pre-industrial in at least one season (medium confidence). { & }. 27. 28 Past emissions alone are unlikely to raise global-mean temperature to C above pre- 29 industrial levels but past emissions do commit to other changes, such as further sea level 30 rise (high confidence).
