Giant machines sucking carbon dioxide out of the air to fight climate change sounds like science fiction, but it's close to becoming a reality, with billions of dollars of support from the U.S. government. And a key player in this growing industry is a U.S. oil company, Occidental Petroleum.With a major petroleum company deploying this technology, it begs the question, is it meant to save the planet or the oil industry? NPR's Camila Domonoske reports.Email us at considerthis@npr.org.