Researchers at City College of New York (writing in the journal Science) found that actually implementing all of the alternative energy generation types available now (concentrated solar thermal energy, nuclear energy, geothermal and hydroelectric plants, wind energy, photovoltaic cells, and biomass) could "could replace all fossil fuel power plants". As if that's not enough, they even claim that plug-in hybrid vehicles could replace 80 percent of the gasoline used in the United States. The problem – and you knew there was a problem – is cost. Their estimate to reduce fossil fuels by 70 percent is $200 billion per year for 30 years. Yikes. But it'd be money well-spent.
[Source: Technology Review]