Back in the 1980s, we started looking at this weird phenomenon: Large sections of coral reefs were turning white, literally over a couple of weeks. And no one really knew why this was," says University of Queensland professor Ove Hoegh-Guldberg in Chasing Coral. "As we did more and more experiments, it turned out that it wasn't a disease. It wasn't too much light. And the only thing you could do in an experiment that would cause corals to go white was to raise the temperature by two degrees Celsius."

What was a curiosity in the 1980s is now an epidemic: In the last 30 years, we've lost 50 percent of the world's corals, as colorful, vital reefs have died off—turning bone-white as the water around them absorbs the heat of a warming planet. Once bustling with life, the reefs now stand as pale and empty as underwater graveyards. "Coral bleaching itself is a stress response, much like a fever in humans is a stress response," says Hawai'i Institute of Marine Biology coral reef biologist Dr. Ruth Gates. Stress is high.

With 2012's gorgeous Chasing Ice, director Jeff Orlowski captured the intense horror of watching our planet's glaciers disappear. Chasing Coral, which debuts on Netflix on July 14, follows suit, trading the Arctic for jewel-blue oceans: Using macro, micro, and time-lapse images of coral reefs as they thrive and die, Orlowski has crafted another visually stunning film about humans' destruction of the planet.

From Hawaii to the Bahamas to Australia, Orlowski and his crew (including underwater photographer Richard Vevers and camera technician and "coral nerd" Zackery Rago) convey the jaw-dropping enormity of our ecological crisis alongside the hallucinogenic beauty of the life that—for now, at least—clings to the reefs lucky enough to avoid bleaching.

Watching Chasing Coral is a remarkable experience, one that teeters between overwhelming the viewer with the scope of earth's ruin and inspiring them to find ways to help. It's to Orlowski's credit that for all of Chasing Coral's horror and grandeur, the focus isn't only on how we've destroyed the earth's oceans, but how we can ensure our destruction goes no further. Early on, Rago explains why the aquariums in his home are full of corals rather than fish. He likes the chain of responsibility. "If a coral dies," he says, "it's your fault." recommended