This is a guest post by David Suzuki.
The Heartland Institute’s recent International Climate Change Conference in Las Vegas illustrates climate change deniers’ desperate confusion. As Bloomberg News noted, “Heartland’s strategy seemed to be to throw many theories at the wall and see what stuck.” A who’s who of fossil fuel industry supporters and anti-science shills...
- Ph.D., Isotope Geology, Australian National University (1971).
- Ph.D., Sedimentology and Structural Geology, Slovak Academy of Sciences (1968).
Jan Veizer is an emeritus professor of Geology at the University of Ottawa (Emeritus since April 2004) where he held the NSERC/Noranda/CIAR Research Chair in Earth Systems. From 1992 to 2004 he also served as the Director of the 'Earth System Evolution Program' of the Canadian Institute for Advanced Research (CIAR).
Veizer retired from the Chair of Sedimentary and Isotope Geology at Ruhr University in Bochum, Germany. 
Veizer has published papers, one with fellow skeptic Nir Shaviv, suggesting that CO2 has a lesser effect on climate change than other factors. Veizer was also a speaker at the Heartland Institute's 2009 International Conference on Climate Change.
Stance on Climate Change
“MANY people think the science of climate change is settled. It isn't. And the issue is not whether there has been an overall warming during the past century. There has, although it was not uniform and none was observed during the past decade. The geologic record provides us with abundant evidence for such perpetual natural climate variability, from icecaps reaching almost to the equator to none at all, even at the poles.” 
“Empirical observations on all time scales point to celestial phenomena as the principal driver of climate, with greenhouse gases acting only as potential amplifiers.” 
Appeared in the film, “The Cloud Mystery” (see part 4 of 6, at 8:20), a film that documents the the research of fellow skeptic Henrik Svensmark who also believes that solar rays have a stronger influence than carbon dioxide on climate change. 
September 13, 2007
Veizer is the co-author of a study titled “Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era,” published in Nature.
Interestingly, the abstract for the study concludes:
“Our results are consistent with the proposal that increased atmospheric carbon dioxide concentrations drive or amplify increased global temperatures.”
While some sources suggest that in this Veizer is contradicting his previous study, Veizer was interviewed by Steve Milloy of Junkscience.com, and he claimed that the new study actually confirmed his original conclusions. 
Milloy had this to say: 
“First, Veizer reluctantly told me the 'text' of the Nature study, that is, the above-quoted conclusion, represented a 'compromise' between the study’s disagreeing authors where Veizer’s side apparently did all the compromising for reasons that had little to do with the science.
While Veizer didn’t want to elaborate on the politics of the Nature study, he told me 'not to take the tone of the paper as the definitive last word.'
Veizer went on to say that the new Nature study has not refuted his original study. The new study, in fact, appears to have confirmed the original study with respect to its most important point that the historical sea surface temperature data indicate atmospheric carbon dioxide does not drive global temperature.”
Together with Nir J. Shaviv, an Israeli astrophysicist and climate change skeptic, Veizer published a paper in Geological Society of America suggesting a reduced influence of carbon dioxide to Climate Change as opposed to a more significant influence from cosmic rays.
Several German (Veizer has been working in Bochum as well) IPCC oriented climatologists reacted toward the first summary of the paper with a sharp press release published by Potsdam Institute für Klimafolgenforschung (PIK) that denounced the paper as “useless,” “outdated” and questioned whether the researchers and their methods were reputable. 
Spoke at the Eleventh Annual V. M. Goldschmidt Conference. His speech was titled “Four Billion Years of Carbon Cycle: What's in It for Us?”, and focused on how “water vapour may have been the most important greenhouse gas.” 
December 7, 2000
Veizer co-authored a paper with Yves Godderis and Louis M. Franç titled “Evidence for decoupling of atmospheric CO2 and global climate during the Phanerozoic eon” that concluded atmospheric carbon dioxide concentrations may not be the principal driver of climate variability on geological timescales.
Sample publications include:
- Shaviv, Nir J.; Veizer, Ján (2003), “Celestial driver of Phanerozoic climate?”, GSA Today. 13 (7): 4–10.
- Veizer, Ján; Godderis, Yves; François, Louis M. “Evidence for decoupling of atmospheric CO2 and global climate during the Phanerozoic eon.” Nature, 408, 698-701 (7 December 2000).
- Rosemarie E. Came1, John M. Eiler, Ján Veizer, Karem Azmy, Uwe Brand & Christopher R. Weidman. “Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era,” Nature, 449, 198-201 (September 13, 2007).
“Jan Veizer, Distinguished University Professor (Emeritus),” Profile at the University of Ottawa. Accessed February, 2012.
Jan Veizer. “Climate change science isn't settled,” The Australian, April 24, 2009.
“Cosmic rays set climate change on Earth, expert says OTTAWA - Stars, not greenhouse gases, are heating up the Earth,” The Edmonton Journal, March 16, 2006.
“The Cloud Mystery 4/6,” YouTube video. Uploaded by user ekstragrim, March 7, 2009.
“New Nature paper: Jan Veizer Contradicts His Own Results?”, jennifermarohasy.com/blog, September 16, 2007.
Steven Milloy. “Japan Sweats for Global Warming,” JunkScience.com, September 13, 2007. Archived February 6, 2010.
“Schlagabtausch über die Ursachen des Treibhauseffekts - zurück zur sachlichen Diskussion” (Press Release), idw, October 31, 2003.
Veizer, Jan. “Four Billion Years of Carbon Cycle: What's in It for Us?”, Eleventh Annual V. M. Goldschmidt Conference; 01 May 2001. 2001.
“Heartland Experts: Jan Veizer,” The Heartland Institute. Accessed February, 2012.
“A critique on Veizer’s Celestial Climate Driver,” RealClimate, May 19, 2005.
“Canadian scientist rocks climate change boat,” CBC News, Dec 7, 2000.
“Jan Veizer,” SourceWatch Profile.
“Jan Veizer,” Wikipedia entry.