When Louis Levanti woke up one morning last September, climate change wasn’t on his mind. “I was never huge into researching climate change, but I was aware that it is real.” So when the 24-year-old TikTok creator, who lives with his parents on Long Island, opened his phone and saw something about a clock being unveiled, he wasn’t initially interested. “I rolled my eyes thinking it had something to do with the stock market.” The Climate Clock, in Union Square in New York City, counts down how much time we have left to act before climate change is irreversible.