Elon Musk talked about how BTC mining with electricity isn't environment friendly but he invented electric cars, in near future if this actually becomes popular electric cars will be available world wide and billions of vehicles will be charged by electricity so how is this environment friendly?
The use of electric cars will become more harmless to the planet than the use of cars with internal combustion engines only when electricity is generated entirely from renewable sources such as solar panels, wind turbines, etc.
While most countries have standard sources of electricity such as thermal power plants or nuclear power plants and the like, the planet's pollution will not fall much. So yes, Elon Musk may have started with electric cars, but there are still many things that need to be change.