"I think we're all shifting our behaviour, I really do," Sir David stated in an interview with the BBC.
Describing plastic pollution as "vile" and "horrid", he said there was growing awareness of the damage it can do.
"I think we are changing our habits, and the world is waking up to what we've done to the planet," he said.
Sir David was speaking as he and the BBC's Natural History Unit (NHU) were announced as the winners of the prestigious Chatham House Prize for their Blue Planet II series of documentaries.