Biofuel alternatives to oil are third-generation. The next step is life forms that feed on CO2 and give off fuel such as methane gas as waste, says biotech expert Craig Venter (who sequenced the human genome in 2001.)
He wants to create new organisms with synthetic genes that input CO2 and output methane. (The organisms would have a suicide gene so if they escaped from the lab, they couldn’t reproduce.)
He says “”We have modest goals of replacing the whole petrochemical industry and becoming a major source of energy, we think we will have fourth-generation fuels in about 18 months, with CO2 as the fuel stock.”
The more ideas like this, the better. Eventually some of them will go mainstream and clean, renewable energy will then become commonplace.