The seven-year cycle of scientific assessment driven by the United Nations Intergovernmental Panel on Climate Change (UN-IPCC) has begun, with Lab scientist Paul Durack invited to contribute as a lead author for the sixth assessment report (AR6), chapter three, “Human Influence on the Climate System.”
This contribution continues a four-decade legacy of Lawrence Livermore National Laboratory (LLNL) involvement in the IPCC, with scientific leadership provided through all five of the IPCC assessments dating back to the initial report, published in 1990. From 1990 to the last assessment in 2013, 28 LLNL scientists have contributed to these reports, with Larry Gates and Don Wuebbles as lead authors in AR1, Gates and Ben Santer as convening lead authors in AR2, Curt Covey and Gates as lead authors in AR3 and Karl Taylor as a lead author in AR4. In the fifth assessment (AR5), Peter Gleckler and Taylor were involved as a lead author and review editor, respectively, and Philip Cameron-Smith, Durack, Detelina Ivanova, Stephen Klein, Jeffrey Painter, Santer and Ken Sperber provided guidance as contributing authors covering seven of the 14 chapters.
In addition to IPCC involvement, LLNL scientists have been playing a foundational role in preparation for the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The various phases of the CMIP project grew from the earlier Atmospheric Model Intercomparison (AMIP) activities and was the reason that the Program for Climate Model Diagnosis and Intercomparison (PCMDI) was founded at LLNL in 1989.
Along with the scientific leadership of the Model Intercomparison Projects (MIPs), LLNL also has been contributing to this international project through the development of the Earth System Grid Federation (ESGF), a project led by Dean Williams and his team. The ESGF system is expected to host 20-plus petabytes of CMIP6 data across the international federation in the next couple of years, building on the success of ESGF with the previous CMIP5 phase data, which totaled 2 petabytes.
In addition to CMIP6 and ESGF leadership, a number of other projects are being led by LLNL scientists. Input4MIPs leverages the ESGF infrastructure to host forcing data being used to drive simulations of historical and future climate and has streamlined data access for the 39 international modeling centers contributing to CMIP6. The obs4MIPs project aims to bring observational datasets to the models, facilitating observation-model intercomparison and analysis, and exposing a multitude of observational datasets to analysts by leveraging the data conventions that have been developed as part of the numerous MIPs.
CMIP6 simulation data is expected to become available in June and the IPCC sixth assessment report (AR6) is due for publication in 2021.