I have served on many national and international committees, including National Research Council/National Academy of Science committees, panels and/or boards. I co-chaired the international Climate Variability and Predictability (CLIVAR) Scientific Steering Group of the World Climate Research Programme (WCRP) from 1996 to 1999 and I have served as a member and officer of the Joint Scientific Committee that oversees the WCRP as a whole from 1998 to 2006. I chaired the WCRP Observations and Assimilation Panel from 2004 to 2010, and from 2010 to 2014 I chaired the Scientific Steering Group of GEWEX: the Global Energy and Water Exchanges program of WCRP. I was co-chair of the CLIVAR “Consistency between planetary energy balance and ocean heat storage (CONCEPT-HEAT)” working group, 2014-18. I have been involved in global warming science and extensively involved in the Intergovernmental Panel on Climate Change (IPCC) scientific assessment activity as a lead author of individual chapters, the Technical Summary, and Summary for Policy Makers (SPM) of Working Group (WG) I for the Second, Third and Fourth Assessment Reports (SAR, TAR and AR4; IPCC 1996, 2001, 2007). I was a Coordinating Lead Author for the SAR and AR4; in the latter I led Chapter 3 that dealt with observations of surface and atmospheric climate change. I was a Review Editor of the Fifth IPCC Assessment Report (AR5) in 2013. Accordingly, I shared the Nobel Peace Prize in 2007 that went to the IPCC and Al Gore. In 2017 I was awarded the prestigious Roger Revelle Medal by the American Geophysical Union. I recently published a book on “The Changing Flow of Energy Through the Climate System” (2022) through Cambridge University Press.