The Earth is running a slight fever from greenhouse gases, after enjoying relatively stable temperatures for 2,000 years. The National Academy of Sciences, after reconstructing global average surface temperatures for the past two millennia, said Thursday the data are "additional supporting evidence ... that human activities are responsible for much of the recent warming." Other new research showed that global warming produced about half of the extra hurricane-fueled warmth in the North Atlantic in 2005, and natural cycles were a minor factor, according to Kevin Trenberth and Dennis Shea of the National Center for Atmospheric Research, a research lab sponsored...