Tech’s green wave hits choppy waters [Video]

Tech entrepreneurs have spent years selling the dream that we can save the planet without changing our ways, but the current focus of innovation is dividing experts and investors.

The tech industry loves splashy world-saving ideas and spends billions on the hunt for new energy sources, often clashing with calls from activists and experts simply to use less energy.

The Web Summit in Lisbon this week, one of Europe’s biggest tech events, gave top billing to a Californian firm called Twelve that claims to be able to make sustainable jet fuel out of the carbon dioxide in the air.

“In a lot of ways we’re mimicking trees and plants,” Twelve cofounder Etosha Cave told the audience, describing a process that takes carbon dioxide out of the atmosphere and converts it into fuel.

Cave …