On the day before Earth Day, hundreds of students from the University of Vermont and other colleges on Thursday heard Sen. Bernie Sanders talk about climate change. Sanders is chairman of the U.S. Senate Green Jobs and the New Economy Subcommittee. Millions of good-paying green jobs could be created, he told the students, as the energy system in the United States is transformed from fuels like oil and coal that scientists say cause global warming to clean energy sources. Earlier this week, for example, Sanders took part in a groundbreaking ceremony for a new solar demonstration project at the Vermont National Guard headquarters in South Burlington.  Sanders secured $8.5 million for the project.  Solar, wind, geothermal and other sources of energy are among the smart responses to global warming phenomenon that Sanders called the biggest environmental challenge today.