Simply put, “Planet Earth” is the most important program of our generation. It makes writing about it almost beside the point; the program, whose second installment “Planet Earth II” is debuting on BBC America this Saturday, is an exquisitely rendered documentary of the natural world. It’s a uniquely dichotomous achievement, one that combines our expanding technologies and cinematic skills with the remote wildness of habitats without humans. It makes for a program that offers a vision of humanity’s relationship with our environment at its absolute and most idealistic best: One where we work mightily to contemplate, understand, and admire the mysterious natural world around us.

For viewers familiar with “Planet Earth,” “Planet Earth II” offers many of the same pleasures — except with even more high-definition, immersive visuals, and a gorgeous score by Hans Zimmer, Jasha Klebe, and Jacob Shea that inspires wonder. This is a show made for the fanciest television screens, the expensive sound systems; it’s worth savoring the lush texture of “Planet Earth II,” from its stop-motion depiction of molten lava forming islands in the Pacific Ocean to the susurrations of starlings taking wing en masse over Rome. The seven new episodes include a making-of episode to cap the season and an exploration of six very different land habitats: islands, mountains, jungles, deserts, grasslands, and — wait for it — cities.

“Cities” is where “Planet Earth II” is at its most humane and magnificent — its most optimistic and purely painful. The series as a whole is a labor of love to the planet that nurtures us, and as a result is an implicit call for conservation and further ecological study. In “Cities,” “Planet Earth II” examines animal populations in cities that take advantage of human structures for their own benefit — like peregrine falcons, who have amassed in huge numbers in New York City, because the skyscrapers and concrete-fueled thermals mimic the sheer cliffs of their preferred nesting grounds. There are stories of great sadness in cities, too, as is too often the case for wildlife as civilization encroaches on it. But “Planet Earth II” affords both a cautionary tale and a message of incredible, unbelievable hope: There is a way for humans and animals to live together in harmony, if we are willing to understand and invest in that future.

There is no one quite like David Attenborough for narrating the private lives of animals; with his signature dry British wit, he can make “human” drama out of the breeding antics of Australian bowerbirds and pygmy sloths, in the midst of offering pithy observations about the very nature and fragility of life on this endlessly surprising and diverse planet. Attenborough and “Planet Earth II” can make the solitude of an albatross waiting for his mate into heartbreaking drama; it shouldn’t be possible, and yet the show manages emotional investment like this over and over again.

2016 was the hottest year on record. Arctic sea ice is at record lows. Oxygen levels in oceans have dropped dramatically. Pollution is so widespread, industrial chemicals have contaminated even the most remote depths of the ocean. “Planet Earth II” is more vital and necessary than ever — a love letter that reads like a historical document, in homage to a planet that may not be able to support this magnificent biodiversity much longer. As a show, it is masterful work. As an instrument of love and affection for the multitudes of life on this fragile world, it is indispensible.

TV Review: ‘Planet Earth II’

Nature Documentary, 7 episodes (2 reviewed): BBC America, Sat. Feb. 18, 9 p.m. 60 min.

  • Crew: Executive producers, Michael Gunton
  • Cast: Narrated by David Attenborough