LiveScience: In perhaps some good news for the environment, Americans are using less energy overall and making more use of renewable energy resources, scientists report today. The United States used significantly less coal and petroleum in 2009 than in 2008, and significantly more wind power, according to energy flow charts released by Lawrence Livermore National Laboratory (LLNL), a government national security laboratory in Livermore, Calif. There also was a decline in natural gas use and …