Planet in Peril: A CNN Worldwide Investigation. Cable News Network (CNN) and Warner Bros. Home Entertainment Company. (2007). Grades 9-12. Bringing viewers the stories behind the statistics, CNN anchor Anderson Cooper, chief medical correspondent Dr. Sanjay Gupta and Animal Planet host and wildlife biologist Jeff Corwin will focus on four main issues that threaten the planet and its inhabitants: climate change, deforestation, species loss and overpopulation.