political agenda and the views of the environmentalists. He reiterated the view that man-made global warming was fabricated by the environmental movement, particularly Environment Canada, in a presentation he gave in June 2006 to the Comox Valley Probus Club. Ball was also a frequent guest on Coast to Coast AM, an alternative media radio show. On July 21, 2011, while a guest on the show, he stated: "To suggest that 's a pollutant when it's an extremely important gas in the atmosphere for all plant life and therefore for the oxygen that's produced, is just nonsense." He is also one of the signatories of the Manhattan Declaration on Climate Change. Ball also, along with Tom Harris, argued that the National Climatic Data Center misleads the public by announcing premature results from their temperature datasets based on incomplete data, and then quietly updating the data when they gain access to all of it, usually diminishing the warming trend in doing so. He also wrote about ocean acidification from a similarly skeptical point of view, arguing that "Even if increases to 560 ppm by 2050, as the IPCC predict, this would only result in a 0.2 unit reduction of pH. This is still within the error of the estimate of global average [which is 0.3 units]." Ball also said that since he became a vocal opponent of the consensus position on global warming, he received five death threats. Michael E. Mann called Ball "perhaps the most prominent climate change denier in Canada." The Frontier Centre for Public Policy, a Canadian think tank, states that Ball disputed anthropogenic global warming since the mid-1990s, and asserted that global warming is due to natural variations. Ball spoke twice at The Heartland Institute's International Conference on Climate Change, where he was presented as a former climatology professor at the University of Winnipeg. However, critics pointed out that Ball was a professor of geography, not climatology, and that the University of Winnipeg never had a climatology department. Ball replied that the climate program at The University of Winnipeg was part of the geography department in the early 1980s. He also asserted that websites such as DeSmogBlog made false charges about his credentials and professional qualifications. From 2002 to 2007, Ball wrote 39 opinion pieces and 32 letters to the editor in 24 different Canadian newspapers, and from 2002 to 2012, he gave over 600 public talks about