"Look Down at Your Body. You Have Become a Coral."

In a lilac-colored room off the Stanford University quad, Brian Perone settled a bulky Oculus Rift virtual reality headset over my face, abruptly transporting me to the sandy floor of a sun-dappled ocean.

Animated marine life flashed in the digital depths: angelfish drifted in loose schools; butterflyfish flitted through orange corals. A shark cruised in the three-dimensional distance.

The cool voice of a female narrator filled my headphones. "Look down at your body," she commanded. "You have become a coral, an important part of this underwater ecosystem." Sure enough, my legs had been transformed into a lumpy pink pillar, my arms into branching prongs.

"One of the unique affordances of virtual reality is that you can go places you couldn't logistically or safely go otherwise," Perone, an earnest, clean-cut PhD student at Stanford's Virtual Human Interaction Lab, said over the narration. "And you can become things you couldn't become in the real world."

I had come to VHIL to bear witness to the future of our oceans and experience the power of environmental empathy. Over the next century, biologists fear, our seas will absorb enough human-produced carbon dioxide to radically alter their chemistry, a crisis dubbed ocean acidification. As the ocean's pH drops, the molecules with which corals, oysters, pteropods and other critters build their shells will grow scarcer, perhaps spelling doom. Some scientists call ocean acidification climate change's "evil twin."

Unlike climate change, however, acidification remains obscure: As of 2010, only23 percent of Americans had even heard of the phenomenon. That's likely because the hidden, creeping devastation wrought by acidification is far harder to observe than the droughts and wildfires exacerbated by climate change (unless you're an oyster farmer, that is).

"Very few people have firsthand experience diving among the coral and the fish that will eventually disappear if our behavior doesn't change," wrote Jeremy Bailenson, director of VHIL, last year. "And even those who do can't see the degradation in real time."

Virtual reality can fill that experiential void. "Reading about ocean acidification teaches you pretty well," Perone said as the simulation kicked into gear. "Watching a movie teaches you a little more. But having an immersive experience works the best."

Within my headset, VHIL programmers had compressed several decades of chemical reactions into five minutes of fast-forwarded cataclysm. As I looked on in alarm, green scum streaked the rocks, and the water turned murky. Schools of wrasse vanished, one after the other, like a blackout spreading across a grid.

"Watch as your coral polyps die and your body starts to dissolve," the narrator intoned dispassionately. I glanced down to find that a furry patina of algae had coated my coralline corpus. "Your limbs will break off as the strong ocean current pushes against you." Shards of my pink skeleton settled to the seafloor. A wave of melancholy broke over me.

No doubt the grim simulation was awakening me to the perils of ocean acidification. But while education is well and good, knowledge means little unless it becomes action. Could virtual reality truly inspire me to be a better environmentalist?

The work of Bailenson and the VHIL would suggest so. In one of the lab's many simulations, participants wandered through a virtual forest, using joystick-controlled chainsaws to fell trees with a crash piped in through a surround-sound system. Afterward, when a researcher "accidentally" spilled a glass of water, subjects who had cut down trees used 20 percent fewer paper towels to wipe up the mess.

Another iteration installed undergrads in the bodies of cows. "You're crawling around the floor, eating hay and drinking water from your trough," Perone explained. "And then a truck backs up to take you away to the slaughterhouse." In subsequent food diaries, the ex-cows reported eating less meat.

Perone doesn't know whether his ocean acidification simulation will work equally well: He's administered it to high school students and undergrads, but hasn't yet analyzed his data. Among the big questions: Do people learn better and care more when they become coral? Or does simply watching the carnage through the eyes of a simulated scuba diver do the trick? In other words: Do we respond only to empathy, or are we capable of sympathy, too?

The jury's still out, but I, for one, found empathy a powerful force. Back in my headset, I had a moment to contemplate the desolate ocean and the mega-bummer of my fragmented body. Then the sparkling, healthy reef returned, and the narrator made some not wholly convincing noises about how the oceans can still be saved. "Ending with death seemed like kind of a downer," Perone said.

Hell or Salt Water is a series on Motherboard about exploring and preserving our oceans. Follow along here.