Description given on Youtube:
Dr. Scott Denning VS. Dr. Roy Spencer .
A balanced respectful climate science debate at last.
July 7, 2011: Scott Denning, PhD, Professor of Atmospheric Science, Colorado State University (supporting the dangerous anthropogenic global warming hypothesis) VS. Roy Spencer, PhD, Principal Research Scientist, University of Alabama in Huntsville (opposing the hypothesis).
Source :
http://www.climatescienceinternational.org/index.php?option=com_content&view=article&id=514