Scientist says greenhouse gases

A noted climate scientist and Nobel laureate says “there essentially isn’t any uncertainty” that greenhouse gases, or carbon dioxide emissions, are causing global warming. “Scientists don’t debate that anymore,” said Michael Mann, who appeared at St. Mark’s Episcopal Church in the Clifford community of Amherst Wednesday night as part of a speaker’s series to help people understand global warming. The global temperature rose 1 1/2 degrees Fahrenheit over the past century. If nothing changes for the better, the temperature could rise by 7 degrees Fahrenheit by the year 2100, Mann said, citing research and climate models. “The dirty secret is that we tend to understate what we find in science,” Mann said. One example he cited was a dramatic plunge in the amount of arctic ice in 2007 — the level now stands at 30 percent of what it was in 1980 and the ice that remains is thinner, he said. Warmer temperatures can change wind patterns, cause longer droughts and change rainfall patterns. The situation could affect national security if the Northwest Passage is opened, creating a new coastline to defend. It could threaten water and food security and create a loss of fresh water and land. Some relatively recent events Mann recalled: n A 1998 outbreak of mosquito-borne West Nile Virus in New York, after an unusually warm winter. n The European heat wave in 2003, which produced the warmest summer in 500 years. n Hurricane Irene caused record rainfall and flooding in August. The sea surface temperatures were warm that summer. Mann said scientists can't really say global warming causes hurricanes, but climate change will create stronger storms and more hurricane-related rain. If the international community doesn’t act, the cost of inaction will increase as time goes on, he said. “We will be leaving our children and grandchildren a different planet,” he said. Mann, a Penn State University professor, is director of the school’s Earth System Science Center and was an assistant professor at UVa’s Department of Environmental Sciences. Mann is known for a book he co-authored with climate scientist, Lee R. Kump, titled, “Dire Predictions: Understanding Global Warming” in 2008. Mann shared the 2007 Nobel Peace Prize with several authors regarding climate change. He was the lead author on a chapter titled “Observed Climate Variability and Change” in the Third Scientific Assessment in 2001 prepared by the Intergovernmental Panel on Climate Change. Cuccinelli, a global warming skeptic, is seeking records of Mann’s climate-change research at UVa and issued a civil investigative demand for them —equivalent of an administrative subpoena. Under the Fraud Against Taxpayers Act, Cuccinelli wants to investigate whether fraud was committed in obtaining the funding for Mann’s research, paid for with federal and state grants. Other investigations by Penn State and peer academic groups found no wrongdoing. “The truth is that they (climate change skeptics) don't expect to uncover anything,” Mann wrote in The Washington Post in 2010. “Instead, they want to continue a 20-year assault on climate research, questioning basic science and promoting doubt where there is none … Burying our heads in the sand would leave future generations at the mercy of potentially dangerous changes in our climate.”