For those in the climate change field, the long-awaited date has arrived. The international climate change community will be watching closely as events unfold in Stockholm, Sweden this week as the IPCC 36th Plenary Session is convened. The Twelfth Session of Working Group I (WGI-12) will take place from September 23-26. This Session of WGI will discuss the Working Group I contribution to the IPCC Fifth Assessment Report (WGI AR5), accept the underlying scientific and technical assessment, and approve the Summary for Policymakers (SPM).
The Working Group I contribution to the IPCC AR5 provides a comprehensive evaluation of the physical science associated with climate change though its Report – Climate Change 2013: The Physical Science Basis. The Report covers 14 chapters encompassing some 2,000 pages of draft text and over 1,250 scientific figures and graphics. It offers observational assessments of the climate system with separate chapters covering shifts in the atmosphere and surface areas, oceans, and cryosphere. It expands significantly on previous ARs with dedicated chapters on cloud dynamics and aerosols, radiative forcings, carbon and other biochemical cycles, paleoclimate archives, sea level changes, and an evaluation of climate models. Both near- and long-term projections are included in this AR as well as climate-induced phenomena such as monsoon and El Nino and their implications to various regional climatic projections. A number of Annexes including, for the first time, a comprehensive Atlas of Global and Regional Climate Projections, are part of the Report.
The Report was prepared by 209 lead authors and 50 review editors including an additional 600 experts serving as contributing authors. It has been reviewed by almost 1,100 experts and 38 governments and generated more than 54,600 comments. Some 9,200 scientific publications including over 2 million GB of numerical data from climate modeling simulations serve as the technical foundation for this Report making this the most wide-ranging and complete climate change review of its kind ever to be undertaken.
In the lead up to its official release this Friday, much has been discussed in the media since an earlier draft of the report was first leaked late last year. Most of the focus has been centered on the “slow down” in average global temperatures over the past 15 years leading some to claim that climate change had slowed or even reversed itself. Between 1998 and 2012, temperatures continued to rise by 0.05 degrees Celsius. In 2007, the IPCC stated that the rate of warming was 0.13 degrees Celsius per decade between 1951 and 1998. The Report still maintains a warming rate over that same period of 0.12 degrees Celsius per decade.
A closer inspection of the findings, does not support the notion of a permanent cool down and while the lower end of the projected warming has been lowered from 2.0 to 1.5 degrees Celsius (when comparing the 2007 AR4 projections), the Report remains unequivocal in its conclusions regarding long-term global warming. It is expected that these numbers will receive considerable discussion today with the likelihood that the final values will be modified for the final Report.
Sea level rise (SLR), as stated in the Report, provides a smaller though broader range of variation than earlier projected in 2007 with the current average range between 40 and 62 centimeters by the year 2100, depending on future continual GHG loadings. The full range is projected to be between 29 and 82 centimeters, much broader than that predicted in 2007.
The Report (based on the leaked draft findings) will undoubtedly change before its final release this Friday (with the final changes being made this evening).
For California, the relevance of the Report comes down to how this information will ultimately be used, if at all. Policy makers, applied practitioners, industry, and regulators all stand to benefit from this latest international compendium of climate change science. Moreover, how it will be conveyed to the general public upon whose opinions public policy is largely developed and supported will be just as important. For research findings such as these to have bearing they should ideally be part of the overall informational base used by decision makers in various commercial, industrial, social, and regulatory frameworks. Given its wide-ranging and dramatic implications to many aspects of California society, such inclusion would seem intuitive.
With California’s coastal environments, inland waterways, sensitive species, forested lands, and agricultural economy all standing to be affected by the shifting environmental conditions confirmed in this latest Report, what will be our response? Does this latest iteration of the IPCC, the fifth consecutive of its kind, convey the confidence needed to now implement necessary adaptations to such things as coastal development policy, forest land management, water quality regulation, flood control, water allocation, and dare I say, Bay-Delta governance?
While it is uncertain how our various administrative bodies, public trust resource agencies, private industry, and the general public will react to these latest findings, the unequivocal confirmation of climatic forcings and the monumental international efforts invested into corroborating these facts, leaves little doubt as to what today’s physical science says. Can we be equally as sure of what we will do with this information?
About the Author
Robert Shibatani is a physical hydrologist and long-time consultant for the California water industry. He is on the Editorial Review Board for the Journal of Water & Climate Change (London, UK), is an IWA Specialist Group Member on the Committee on Climate Change and Managed Adaptations (The Hague, NL), and editorial peer reviewer for IWA World Water Congresses. Robert is the CEO of The SHIBATANI GROUP, Inc., an affiliated practice group of international water resource specialists with water governance pursuits in SE Asia, Central Asia, South Africa, Western Africa, Australia and the UK. He is based in Sacramento, California, USA.