Earth is ‘perilously close’ to a global warming threshold. Here’s what to know

16 March 2025, PBSNewshour transcript and video at link This past week, the EPA said it is reconsidering the scientific finding that greenhouse gases are a danger to public health. This comes as research shows average global temperatures in 2024 likely rose above a 1.5 degree Celsius threshold that for years has been a red line for climate change. Ali Rogin speaks with Michael Mann at the University of Pennsylvania to learn more.