1) “Greta Thunberg: A Year to Change the World” (PBS) and “2040” (CW), both 8 p.m. Thunberg, now 18, planned to take a school year (2019-20) off and travel the globe, studying and speaking about climate change. Huge problems followed, including the pandemic, but this three-hour film remains uplifting and idealistic. That’s one of two Earth Day specials on broadcast networks; “2040” (shown here) offers an optimistic view, looking at current programs and envisioning an improved climate in 20 years.
2) “Kingdom of the Polar Bear,” 8-10 p.m. ET, Nat Geo Wild (rerunning at 11); “A Perfect Planet,” 8-10 p.m. Discovery. “Kingdom” spent a year in the Canadian Arctic. “Perfect Planet” shows how natural forces shape our planet; David Attenborough narrates it – and many of the films rerunning today and Friday on BBC America. Other cable reruns: “America’s National Parks” (9 a.m. to 5 p.m., National Geographic), “Serengetti” (2-8 p.m., Discovery), “North America” (6-11 p.m., Animal Planet), more.
3) “Secrets of the Whales,” Disney+. In a three-year, global journey, Brian Skerry found that whales develop their own traditions; this four-parter is beautifully filmed and narrated. Other films also have Earth Day debits on streaming networks: “Endangered” (Discovery +), “Cher & The Loneliest Elephant” (Paramount Plus) and Attenborough’s three-part “Life in Color” (Netflix”). Apple TV+ debuted three films Friday, including Attenborough’s delightful “The Year Earth Changed.”
4) “Hell’s Kitchen” finale, 8 p.m. Thursday, Fox. For the seventh straight time, there wll be a female champion. This time, the finale has Mary Lou Davis, 28, a chef de cuisine (kitchen manager) in San Antonio and Kori Sutton, 37, an executive chef in Los Angeles. They’ve chosen their teams from the previous contestants; now each creates a full menu and dinner service.
5) AND MORE: Amid the Earth Day fuss, Thursday is still the day for ABC dramas, NBC cops and, especially, comedies. CBS has its 8-10 p.m. block, including the terrific “Mom” at 9, with only four new shows left. Fox adds “Last Man Standing” at 9 and “Moodys” (Ann is suspicious about her son, who’s sleeping with her life coach) at 9:30. And at 10, Freeform has “Everything’s Gonna Be Okay.”