By Jennifer O’Connor

Time is running out for polar bears. According to some estimates, unless we drastically reduce our greenhouse-gas emissions, Arctic summer sea ice could disappear by 2030—and two-thirds of the world’s polar bears could be extinct by mid-century. Amid these grim statistics comes a self-serving new proposal being promoted by several U.S. zoos: To “save” polar bears, we should sentence even more of them to life in captivity.

As you mull over this idea, ask yourself: Do zoos really think that displaying depressed and stressed animals will help motivate people to preserve the Arctic environment? Or is this just a ploy to get paying customers through the front gate?

Sorry, does that sound cynical? Consider that one of the facilities on board with this proposal, the Saint Louis Zoo, spent $20 million on a new polar bear exhibit but now has no animals to display there. The zoo would benefit greatly if rules on importing polar bears for public display were relaxed.

But polar bears do not fare well in captivity, and zoos know it. Ronald Sandler, director of Northeastern University’s Ethics Institute, calls polar bears “one of the worst candidates for captivity.”

Polar bears thrive in enormous Arctic expanses and open water—which no zoo can hope to provide. An Oxford University study noted that a typical polar bear enclosure is about one-millionth the size of the animal’s minimum home range and concluded that captive polar bears suffer from both physical and mental anguish.

For evidence of this, we need only remember Knut, the Berlin Zoo’s “star” polar bear, who spent his days pacing incessantly, bobbing his head repeatedly and exhibiting so much captivity-induced mental distress that one German zoologist called him a “psychopath.” Some zoos have attempted to curb such abnormal behaviors by drugging polar bears with anti-depressants. Knut’s half-sister, Anori, who was born in January, is now on display at Germany’s Wuppertal Zoo.

If U.S. zoos are allowed to start importing polar bear cubs, as they’ve proposed, where will the adult animals end up? Babies like Anori bring in big bucks, but as the animals get bigger, crowds grow smaller. Visitors lose interest and move on, while adult animals languish behind bars—warehoused, sold or bartered like damaged goods. Before Knut died at the age of 4, the Berlin Zoo attempted to unload him onto another facility.

Not a single U.S. zoo has a policy of providing lifetime care for the animals at its facilities, and many zoos breed animals knowing in advance that the males will be difficult to place when they mature.

Some zoos take drastic measures to deal with the “surplus.” Animals from zoos have ended up at dilapidated roadside zoos, traveling circuses and even canned-hunting facilities, where they are easy marks for hunters seeking trophies for the den. One Swiss zoo killed two endangered lion cubs simply because it didn’t have room for them. The Cleveland Metroparks Zoo’s chief of veterinary services has even called on members of the zoo community to support the use of surplus zoo animals in medical experiments.

Zoos talk a lot about “conservation,” but none of the elephants, gorillas, tigers, chimpanzees or pandas born in zoos will ever be released back into their natural environments. In the case of polar bears, where would they be released exactly, if the Arctic ice disappears? Putting animals on display doesn’t even foster respect for their wild cousins. They are still hunted, poached, culled and captured for exhibits.

If we truly want to save polar bears, then we must save their habitat—by doing whatever it takes to cut our greenhouse-gas emissions. That’s the kind of campaign that deserves our support. Condemning animals to a life sentence behind bars is not the solution.