Frozen Planet was a critically acclaimed BBC documentary series narrated by David Attenborough, the velvety-voiced British answer to Morgan Freeman, featuring breathtaking footage of some of the rarest and fuzziest animals on Earth—and ending with an episode discussing the threat of climate change to these animals and their homes. Or at least it did in the U.K.
The final episode of the series, titled "On Thin Ice," was made an optional extra for networks looking to syndicate the show in America and other markets. The BBC's apparent reasoning was that that it'd be easier to sell the series without it in foreign markets, particularly the U.S., where climate change is a divisive issue.
So in essence, British people got to watch an entire extra episode of a show full of footage of polar bears and penguins because the BBC didn't want to deal with the hassle of climate change deniers. After the story broke, the network claimed the episode was made an optional extra for foreign networks because it featured Attenborough prominently; it's standard practice for foreign networks to dub over him and cut his scenes, which would be difficult if he was physically in frame for half the episode. Apparently over a third of markets who paid to syndicate the show opted out of airing "On Thin Ice," and it almost didn't air at all in the U.S.—the Discovery Channel only aired it in response to the controversy.