“Greed of the fossil fuel industry” is “destroying our planet,” says Sen. Bernie Sanders. Young people agree. Their solution? Socialism.

Rep. Alexandria Ocasio-Cortez says socialism creates “an environment that provides for all people, not just the privileged few.”

“Nonsense,” says Tom Palmer of the Atlas Network in my new video.

Palmer, unlike Ocasio-Cortez and most of us, spent lots of time in socialist countries. He once smuggled books into the Soviet Union.

What he’s seen convinces him that environmental-movement socialists are wrong about what’s “green.”

“We tried socialism,” says Palmer. “We ran the experiment. It was a catastrophe. Worst environmental record on the planet.”

In China, when socialist leaders noticed that sparrows ate valuable grain, they encouraged people to kill sparrows.

“Billions of birds were killed,” says Palmer.

Government officials shot birds. People without guns banged pans and blew horns, scaring sparrows into staying aloft for longer than they could tolerate.

“These poor exhausted birds fell from the skies,” says Palmer. “It was insanity.”

I pointed out that, watching video of people killing sparrows, it looked like they were happy to do it.

“If you failed to show enthusiasm for the socialist goals of the party,” Palmer responds, “you were going to be in trouble.”

The Party’s campaign succeeded. They killed nearly every sparrow.

But “all it takes is two minutes of thinking to figure, ‘Wait. Who’s going to eat all the bugs?'” says Palmer.

Without sparrows, insects multiplied. Bugs destroyed more crops than the sparrows had.

“People starved as a consequence,” says Palmer. “People confuse socialism with … a ‘nice government’ or a ‘government that’s sweet’ or ‘made up of my friends.'”

Socialism means central planning. That ends badly.

“What AOC wants to do is basically give the Pentagon, or similar agencies, control over the entire society. She thinks that’s going to turn out well,” says Palmer. “It’s a joke.”

China’s central planners keep making mistakes.

Many Chinese lakes and rivers are bright green. Fertilizer runoff created algae blooms that kill all fish. A Lancet study says Chinese air pollution kills a million people per year.

Wherever socialism is tried, it creates nasty pollution.

In the Soviet Union, Joseph Stalin wanted cotton for his army. His central planners decided it should be grown near the Aral Sea. They drained so much water that the sea, once the fourth biggest inland lake in the world, shrank to less than half its size.

“Soviet planners caused catastrophic environmental costs to the whole population,” says Palmer.

I push back. “That was then. Now the rules would be different. Now the rule would be: ‘green.'”

“All the time we hear socialists say, ‘Next time, we’ll get it right.’ How many next times do you get?” asks Palmer.

Yet American media still sometimes say socialists protect the environment. A New York Times op-ed claims “Lenin’s eco warriors” created “the world’s largest system of most protected nature reserves.”

“These are not nature preserves,” Palmer responds. “They use it as a dumping ground for heavy metals, for radioactive waste — in what sense is it a nature preserve?”

Capitalists destroy nature, too. Free societies do need government rules to protect the environment.

But free markets with property rights often protect nature better than bureaucrats can.

Private farmers, explains Palmer, are “concerned about the ability of the farm to grow food next year, year after year, (even) after that farmer is gone. Why? Because the farm has a capital value. That’s the ‘capital’ in capitalism. They want to maximize that.”

Capitalism also protects the environment because it creates wealth. When people aren’t worried about starving or freezing, they get interested in protecting nature. That’s why capitalist countries have cleaner air.

Also, capitalists can afford to pay for wild animal preserves.

“When no one has property rights and people are poor, tigers and elephants are considered a burden … They kill them,” says Palmer. “When you’re wealthier … you care about the environment.”

Socialists say they care, but the real world shows: to protect the environment, capitalism works better.

        Every Tuesday at JohnStossel.com, Stossel posts a new video about the battle between government and freedom. He is the author of “Give Me a Break: How I Exposed Hucksters, Cheats, and Scam Artists and Became the Scourge of the Liberal Media.”