Oil prices at $75 a barrel and worries about global warming are driving the shift.

Aargh! Where do people get the idea that any alternative to petroleum will help reduce global warming?

Any process that generates energy by burning a hydrocarbon procudes CO2. That most certainly includes biofuels.

(In other news, unless you can find a place to mine hydrogen fuel cells, "hydrogen-powered cars" will also not necessarily reduce total CO2 emissions. Those fuel cells have to be charged up somehow.)