I was reading a book by Mike Berners Lee (brother of Tim) about carbon footprints etc. He includes some light hearted stuff in amongst all the doom. One was he had worked out that an e bike charged from renewable sources was more eco friendly than a push bike powered by food!
I've not read the book (it's on my wish list !) but this kind of comparison is fraught with difficulty. Here's an example ...
https://adventuresportsjournal.com/earth-talk-e-bikes-greener-human-powered-bikes/... which suggests that even if the ebike is powered by dirty coal it's still better than being human powered. But the author is comparing the total impact of food production against just the impact of generating the electricity for the battery. To be a realistic comparison he ought to include the impact of producing the bike, ie all the steel, rubber, plastic, battery, etc, plus the food-powered effort the human still has to put in (ebikes only provide assistance). How did Mr Berners-Lee do his comparison ?
On the topic of ebikes generally, I wish someone would figure out a way of ensuring the power boost can only be used to assist with hills, and doesn't help when the user is simply trying to go as fast as possible on the flat. Having one of these whizz past at speed at close range without warning on a shared path or footpath is scary !