Like dreamers who think they are in total grasp of their reality we may only be conscious of our mortal thoughts. But, obviously, the choice is all yours. There is no paradox in time travel. You are obviously referring to the Bradbury buttercup hoax. Not all temporal missteps lead to fascism.
Bacteria exist in environments, and respond.
So do we, and we consider ourselves intelligent, until it comes to the big bang theory, and then we just lose it. But so does any program in any simulated environment. Add conditions for which a computer program can respond to, and apply an environment which satisfies sufficient criteria and you have a response to an environment. To me, that is not consciousness. Ethical hideousity is whether we should go and interfere with the past.