The Can't Stand Me Now musician was a close pal of Amy when she was making her name in the London music scene, and thinks watching the intimate film would bring back too many memories of the singer, who died in 2011.
"We were all friends with Amy, it's obviously f**king devastating and hard for us all to get over so I've not really been able to watch it yet," he tells Britain's Daily Mirror newspaper. "A lot of people have been affected by it as it brings back memories of the time and it's quite a personal thing."
Carl and bandmate Pete Doherty's closeness to the Back to Black star meant her death hit them especially hard, especially as Pete, like Amy, battled drug addiction in the public eye.
"Amy couldn't step outside her front door without a mob of about 30 blokes thrusting cameras at her," Pete told Britain's Daily Mail newspaper in 2012. "If you then include crack in the equation, it becomes a real killer - especially as Amy didn't do things by halves."