How much carbon emissions would robot taxis save?

Big, intractable problems like climate change don't have a single easy solution—if they did they wouldn't be intractable, after all. Rather, any successful strategy to reduce climate emissions will involve the additive effects of lots of smaller fixes. Not everyone is going to switch their car to a battery electric vehicle (EV) or even a plug-in hybrid EV, barring a government mandate. But there are applications where new technology can be both cost-effective and good for the environment, like Wrightsgeed's plug-in EV drivetrains for delivery trucks.

A paper published today in Nature Climate Change examines the effect to greenhouse gas emissions if another automotive niche converted to a more climate-friendly fleet: what might happen if, in 2030, US taxis were all self-driving, battery-powered EVs?

The authors, Jeffery Greenblatt and Samveg Saxena at Lawrence Berkeley National Laboratory, focus on autonomous taxis as having a viable business model. Many users and frequent trips make up for higher purchasing costs; indeed they point to Uber and Lyft as an analogous car on-demand approach. While their paper looks at autonomous taxis, the calculations are mostly comparing current vehicle efficiencies with predictions for 2030. The benefits of being autonomous (as opposed to human-driven) are assumed to come through more efficient allocation of vehicles—sending the right-sized vehicle to the right customer, balancing use across the fleet optimally, traveling in packs, and so on.