By Kevin Behr

U.S. Sen. Amy Klobuchar called on Congress Monday to take immediate action to combat global warming, recommending federal limits on greenhouse gases and a national reporting system to hold polluters accountable for their emissions.

Among the Minnesota Democrat's proposals was one to convert prairie grasses into "carbon-neutral" ethanol, a biofuel that some University of Minnesota researchers say is cleaner and more efficient than corn or soybean ethanol.

In a noon address before about 200 people at the Humphrey Institute of Public Affairs, Klobuchar, who sits on Senate committees dealing with the environment and agriculture, stressed that there is no single cause of global warming and that many solutions exist.

"We don't need a silver bullet," she said. "We need silver buckshot."

Klobuchar said that the American people have caught onto the issue of global warming and that Congress needs to play catch-up.

"This isn't just about 8-year-olds crying about penguins anymore," she said. "This is about people from all walks of life, rising up and saying we need to do something about this."