Of course it’s proven possible. Are you one of those types that doesn’t think something is shown to be possible until it is already the entire status quo everywhere? At that point, there’s not even any discussion about its “possibility” because it’s the status quo. Solutions exist for these things and whining about how things are not yet ideal, how this earnest effort to clean up should be discouraged because it might backfire or how solar power might not be “proven” even though you can go out and literally buy solar panels (cheaply! And with quick energy payback time!) to charge your car with instead of using oil... ...this is not actually productive. Find a solution and do it.