SUMMARY OF AMICI EXPERT CONTRIBUTIONS REGARDING THE SCIENCE OF CLIMATE CHANGE IMPACTS, ATTRIBUTION, AND RECOVERY 130 Key Findings and Messages Reputable international and domestic scientific bodies, as well as an extensive body of peer-reviewed science, indicate that climate change is causing severe environmental, economic, and social impacts at current levels of planetary warming, and that these impacts will intensify with any additional warming. The occurrence and severity of these impacts is, to varying degrees, attributable to planetary warming above pre-industrial levels. The activities of the respondents to the Petition have materially contributed to a large percentage of this warming. Rapid, large-scale emissions reductions and carbon sequestration are needed in order to meet either the Paris Agreement’s temperature goals or more stringent science-based climate recovery targets. In addition, adaptation to the climate change already underway and expected is essential and requires assessing vulnerability and possible impacts, building resilience, and planning for the consequences. The Commission is to note that each section or sub-section of this consolidated section reflects the position of only those amici indicated in parentheses at the end of the heading for that section or sub-section. Summary Argument I. Climate Change Impacts Globally A. Findings from the IPCC’s Fifth Assessment Report (ClientEarth, Sabin Center, Plan B) The IPCC was established in 1988. The IPCC “assess[es] on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.” 131 Expert scientists from every nation are involved in the drafting of IPCC reports, which are subject to significant scrutiny, debate, and contestation, with input of scientists from around the world. 132 The IPCC’s findings as to climate change impacts are also supported by, and largely consistent with, individual government assessments.133 The most recent report, the Fifth Assessment Report, found that warming of the climate system “is unequivocal,” that present atmospheric concentrations of CO 2, CH4, and NO are 130 This summary was compiled with inputs from Our Children’s Trust (Elizabeth Brown & Danny Noonan), ClientEarth (Sophie Marjanac), the Sabin Center for Climate Change Law (Michael Burger & Jessica Wentz), Plan B (Tim Crosland), James E. Hansen (Dan Galpern), and Kevin E. Trenberth and is based on their previously submitted underlying amicus curiae briefs and letters as well as relevant updates. 131 Intergovernmental Panel on Climate Change (IPCC), History (2017), https://www.ipcc.ch/organization/organization_history.shtml. 132 See INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE, IPCC FACTSHEET: HOW DOES THE IPCC APPROVE REPORTS?, (2013), https://www.ipcc.ch/news_and_events/docs/factsheets/FS_review_process.pdf (providing details of the review process). 133 Sabin Center brief, at p. 4-5; Plan B brief, at § 5.1 (p. 14-16). 32