Michael E. Mann is a prominent American climate scientist known for his work on climate change and the development of the "hockey stick" graph, which illustrates the rise in global temperatures over the past millennium. He has been a strong advocate for climate action and has contributed significantly to the public understanding of climate science. Mann has authored numerous scientific papers and books, including "The Hockey Stick and the Climate Wars" and "The New Climate War." His research often focuses on the role of human activity in climate change, and he has been a vocal critic of misinformation related to climate issues. Additionally, Mann serves as a professor at Penn State University and has been involved in various outreach efforts to communicate the urgency of addressing climate change.