Thomas Stocker Physics Institute Oeschger Centre for Climate Change Research University of Bern, Switzerland Climate Change: Making the Best Use of Scientific Information How hot was the summer 2011 ? European summers of the past 500 years: 2011 was not the hottest summer The 5 coldest occurred before 1924 The 5 hottest occurred after 2001 Climate Change: Making the Best Use of Scientific Information 1.Climate Change: A Naturally Difficult Topic 2.Four Challenges in Communication 3.The Specific Mandate of IPCC 4.Conclusions Climate change: A naturally difficult topic Space scales:10 6 m m Time scales:10 6 s s Climate change: A naturally difficult topic There are no desk-top experiments Where is the smoking gun? Climate is always changing We experience weather, not climate Yet, everybody has an opinion Climate change: A naturally difficult topic The Earth is the centre of the universe Climate change: A naturally difficult topic The Earth orbits around the Sun Space and time are absolute dimensions Matter and energy modify space-time Nature is deterministic Uncertainty principle and deterministic chaos Climate changes are due only to natural processes Humans are modifying global climate Old Paradigm Scientific Fact ? Climate Change: Making the Best Use of Scientific Information 1.Climate: A Naturally Difficult Topic 2.Four Challenges in Communication 3.The Specific Mandate of IPCC 4.Conclusions Four challenges in communication Challenge #1: A widening gap Science Literacy Communication Literacy Scientists Public Science Journalists Four challenges in communication Challenge #2: Many sources of information Scientific publications Lectures and presentations by scientists International Assessments Media: Press, TV, Radio, Movies Social Media: Facebook, Blogs Science popularizations Position papers by Think Tanks Four challenges in communication Challenge #3: Information with Uncertainty How to determine uncertainty? How to display uncertainty? How to formulate uncertainty? Four challenges in communication (Mastrandrea et al., 2011) Challenge #3: Information under Uncertainty How to determine uncertainty? 1.1 to 6.4 C Four challenges in communication (IPCC, 2007, Fig. SPM-5) Challenge #3: Information under Uncertainty How to display uncertainty? Four challenges in communication Challenge #3: Information under Uncertainty How to formulate uncertainty? level of agreement amount and quality of evidence confidence virtually certain 99% very likely 90% likely 66% unlikely 33%... Qualitative: Quantitative: quantified likelihood Do we speak language or jargon? Scientific TermPublic MeaningBetter Choice positive feedbackgood response, praiseself-reinforcing cycle theoryhunch, speculationscientific understanding uncertaintyignorancerange biasdistortion, political motiveoffset from observation schemedevious plotsystematic plan (Somerville and Hassol, 2011) Challenge #4: Precise but non-technical language Do we speak language or jargon? Scientific TermPublic MeaningBetter Choice positive feedbackgood response, praiseself-reinforcing cycle theoryhunch, speculationscientific understanding uncertaintyignorancerange biasdistortion, political motiveoffset from observation schemedevious plotsystematic plan (Somerville and Hassol, 2011) Challenge #4: Precise but non-technical language Do we speak language or jargon? Scientific TermPublic MeaningBetter Choice positive feedbackgood response, praiseself-reinforcing cycle theoryhunch, speculationscientific understanding uncertaintyignorancerange biasdistortion, political motiveoffset from observation schemedevious plotsystematic plan (Somerville and Hassol, 2011) Challenge #4: Precise but non-technical language Climate Change: Making the Best Use of Scientific Information 1.Climate: A Naturally Difficult Topic 2.Four Challenges in Communication 3.The Specific Mandate of IPCC 4.Conclusions The specific mandate of IPCC Principles Governing IPCC Work (1998, 2003, 2006) The specific mandate of IPCC Working Group I: The Physical Science Basis Working Group II: Climate Change Impacts, Adaptation, and Vulnerability Working Group III: Mitigation of Climate Change Authors / RE The specific mandate of IPCC Science Community Governments scoping of outline of assessment approval of outline nomination and selection of experts 0-Order Draft (ZOD) informal review 1-Order Draft(FOD) expert review government review2-Order Draft(SOD)expert review Final Draft (FGD) government review approval of SPM and acceptance of report Lead Authors of Working Group election of WG Sept 2013 Climate Change 2013 Elements of an Assessment Report Report 14 Chapters, Annexes, Supplementary Material target 600 pages (excl. Figures, Tables, and Refs.) Summary for Policymakers target 15 pages (total) Technical Summary target 70 pages (incl. Figures) Synthesis Report all WGs contribute (target 50 pages excl. Figs.) The specific mandate of IPCC Working Group IWGII WGIII Warming in the climate system is unequivocal,... (IPCC, 2007, Fig. SPM-3) A unique way of scientific communication IPCC (2007): Continued GHG emissions [..] would cause further warming and induce many changes [..] that would very likely be larger than those observed [..]. (IPCC, 2007, Fig. SPM-6,7) IPCC (2007): A unique way of scientific communication [..] a 1-in-20 year hottest day is likely to become a 1-in-2 year event [..] in most regions [..]. IPCC SREX (2011): (IPCC, 2011, Fig. SPM-4a) A unique way of scientific communication Climate Change: Making the Best Use of Scientific Information 1.Climate: A Naturally Difficult Topic 2.Four Challenges in Communication 3.The Specific Mandate of IPCC 4.Conclusions Conclusions Communication on climate change faces special challenges in a highly politicized environment; The clearer the scientific evidence for man-made climate change becomes, the more vocal are detractors, often operating as merchants of doubt; Intergovernmental assessments are essential to deal with problems of global impact; IPCC assessments produce the most effective scientific information if they are rigorous, robust, transparent and comprehensive. Communicate the possible futures Make the choice