Quora Questions are part of a partnership between Newsweek and Quora, through which we’ll be posting relevant and interesting answers from Quora contributors throughout the week. Read more about the partnership here.

Answer from Michael Barnard, low-carbon innovation analyst:

Is it really practicable & sustainable to replace 100 percent of today’s fossil-fuel-powered vehicles to electric?

Not today. Not next year. But in the next three to four decades, absolutely.

Battery electric vehicles’ range and performance is increasing much more rapidly than internal combustion vehicles while the price is dropping annually. Estimates vary, but the total cost of ownership of very comparable vehicles is expected to favor electric cars anywhere from 2018 to 2022 without incentives. Right now, there are hundreds of thousands of electric buses on the roads of China, and showing up in the developed world in most countries.

faraday future fastest electric car A Faraday Future FF 91 electric car takes off across the stage in an exhibition of speed during an unveiling event at CES, Las Vegas, January 3. REUTERS/Steve Marcus

Battery electric vehicles depend on electricity from the grid but mostly consume it outside of peak demand hours, so they aren’t going to overload most grids in most places. And with renewables being rapidly implemented on most grids, growth of generation from clean sources is more rapid than growth of consumption from electric vehicles.

Battery electric vehicles are much, much less polluting over their full lifetime than internal combustion vehicles. But they are still manufactured objects. As manufactured objects however, they are one of the more heavily recycled ones. And batteries these days are pretty inert and recyclable too. Tesla, as an example, recoups about 80 percent of the embodied carbon from its cars’ batteries when it recycles them.

Grids globally are getting cleaner. The CO2 emissions per MWH of every grid in the world have started diminishing, even in China and India. And those two countries are heading in the right direction faster than any other countries in the world, with huge renewables programs and coal phase outs under way.

But cars last 11 to 13 years and longer in some places. Existing cars aren’t going to be replaced until they are dead, because running an existing older car is always going to be cheaper — if less reliable, sexy, fun, etc. — than buying a new electric car. It’s going to take a while for the stock of cars to shift globally. My estimates suggest 2040 to 2050. Others have more or less aggressive outlooks, depending on the assumptions that they use.

Is it really practicable & sustainable to replace 100% of today’s fossil fuel powered vehicles to electric? originally appeared on Quora – the place to gain and share knowledge, empowering people to learn from others and better understand the world. You can follow Quora on Twitter, Facebook, and Google+. More questions: