• Invited public lecture, "Dire Predictions: Understanding Global Warming", North Carolina A&T University, Greensboro, NC, February 24, 2009
  
  
• Invited public lecture, "Global Climate Change: The Predictions, The Likely Impacts, and Possible Solutions" (in association with national "Focus the Nation" event), Le Moyne college, Syracuse, NY, January 31, 2008
  
  
• Invited public lecture, "The Science of Climate Change",'EarthTalks' Seminar Series, Earth and Environmental Systems Institute, Penn State Univ, University Park, PA, September 17, 2007
  
  
• Invited public lecture, "Global Climate Change: Past and Future",Straub Environmental Lecture Series, Salem OR, May 31, 2007
  
  
• Invited public lecture, "Global Climate Change: Past and Future",Pennsylvania Consortium for Interdisciplinary Environmental Policy and the Pennsylvania Environmental Council, Harrisburg PA, Oct 5, 2006
  
  
• Invited public lecture, "Global Climate Change: Past and Future", University of California at Santa Cruz, Santa Cruz CA, May 10, 2006
  
  
• Invited public lecture, "Climate over the Past 1-2 Millennia", U.S. National Academy of Sciences, Washington DC, March 3, 2006
  
  
• Invited public lecture, "Global Climate Change: Past and Future", Le Moyne college, Syracuse, NY, February 3, 2006
  
  
• Invited lecture, "Climate Change and Global Warming", Symposium on 'Energy for the 21st Century' , University of Massachusetts, Amherst, MA, April 9, 2005
  
  
• Invited lecture, 'Climate over the Past Millennium or So', Symposium on Whole Earth Systems (Honoring Stephen Schneider), Stanford University, Palo Alto, CA, Feb 10, 2005.
  
  
• Invited lecture (co-authored: K. Briffa), 'Comparisons of Observed Paleoclimate and Model-Based Studies of Climate Changes Over the Past Two Millennia' , First International CLIVAR Science Conference, Baltimore, MD, June 23, 2004.
  
  
• Invited lecture, 'Paleoclimate Implications for Recent Human Influence on Climate' , Annual Seminar of the World Federation of Science, Erice, Italy, August 22, 2003.
  
  
• Invited presentation, 'Climate Changes During the Past Millennium' , AGU Fall meeting, San Francisco, CA, Dec 8, 2002.
  
  
• Invited public lecture, 'Climate Change and Global Warming' , Waxter Environmental Forum, Sweet Briar College, Virginia,  March 14, 2002.
  
  
• Session introduction, Invited session on "Climate Change Detection & Attribution", National Academy of Sciences  Frontiers of Science annual symposium, Irvine, California, Nov 9, 2001.
  
  
• Invited lecture, 'Insights into Climate Dynamics from  Paleoclimate Data' , Richard Foster Flint Symposium Honoring the Memory of  Barry Saltzman, New Haven, CT, November 3, 2001.
  
  
• Public lecture, 'Global Warming' , Undergraduate Environmental Science Organization ('ESO') Global Warming Forum, University of Virginia, February 20, 2001
  
  
• Invited presentation, 'Variability in El Nino and the Global ENSO phenomenon in past centuries' , Global Change Open Science Conference: "Variability in El Nino and the Global ENSO Phenomenon in Past Centuries", Amsterdam, Netherlands, July 11, 2001.
  
  
• Invited presentation, 'Proxy-based Reconstructions of Decadal Variability' , CLIVAR Decadal Climate Predictability Workshop, La Jolla, California, October 4, 2000.
  
  
• Invited public lecture, 'Large-scale Temperature Changes During the Past Millennium' , Smithsonian Environmental Research Center (SERC), Edgewater Maryland, March 15, 2000.