Professor Joe Siracusa says President Biden has not explained how he will pay for the pledges he made at the climate change conference.
World leaders met virtually last week to announce how their countries would reach certain emissions reductions targets.
“There’s no way America is going to go to electric vehicles in 10, 15 or 20 years. The only reason Americans gave up their horses to get into cars was because Henry Ford made them cheap,” Professor Siracusa told Sky News.
“You’ve got all kinds of problems around America and he’s talking about this moral and economic imperative.
“You can talk presidential, but you have to be presidential.”