Michael Mann, a prominent climatologist and former University professor, spoke yesterday in Clark Hall about the growing evidence of global climate change and the increasing "politicization of science" as part of the annual EnviroDay symposium. Mann is currently a professor at Pennsylvania State University, and the global climate change research he conducted while at the University from 1999 to 2005 is currently the subject of two lawsuits by Virginia Attorney General and University alumnus Ken Cuccinelli and the American Tradition Institute, a conservative think tank. In his talk, Mann said human-caused warming of the planet has had a discernible impact on the climate, pointing to evidence from modern day models which show global climate change's relationship with human emissions and carbon footprints. He added that the average American emits about 20 metric tons of carbon per year, which is the equivalent to two large adult elephants, and said if the rate of man-made carbon emissions continues to accelerate there can easily be a four-to-five degrees Celsius increase in temperature from pre-industrial times. This would be a change significant enough to disrupt global equilibrium. He also discussed perhaps his most well-known piece of research: the hockey stick graph. "It turns out that modern warming takes us outside of the range of what we think temperatures have been in the past thousand years," Mann said. "And because of the shape of this curve, you can see there's sort of this long term decline, which you might think of as a shaft, and then there is the recent warming. You may think of that as the blade." Although Mann's research has attracted nationwide attention and controversy, he said a large amount of research reaches the same conclusion. Mann also spoke about what he calls the "politicization of science," or the rising skepticism and involvement of politicians in global climate change research. Because greenhouse gases are at the very core of modern global energy, he said, "there are fairly powerful vested interests who profit greatly from our current reliance on fossil fuels, and they don't want to see that much change in the future." Issues involving climate change research came to the public's attention just before the 2009 Copenhagen Summit on reducing carbon emission, Mann said, when emails of climate change scientists emerged and words were taken out of context by politicians and members of the press. In 2005, Mann was subpoenaed to appear before government officials and a lawsuit was later filed in an attempt to obtain emails and other documents of Mann's, prompting significant nationwide media discussion. "I should say [the University] took a very brave stance against this yet again obvious effort to intimidate scientists" who might be doing research that is "disadvantageous to certain [industry] leaders that may or may not be contributing to the campaigns of certain politicians," he said. Mann said to help stop global climate change, "we could have a good faith debate about what sort of policies [to pursue]. What we can't participate in a debate about anymore is the reality of the problem." EnviroDay is an annual student research symposium for the environmental sciences and Mann was selected by the event organizing committee as the keynote speaker.