Shrinking humans like they do in 'Downsizing' is actually somewhat possible — and not such a bad idea

Paramount

• The movie "Downsizing" imagines a world where a small percentage of the population elects to shrink themselves to 5 inches tall.
• In the downsized world, people are richer, and their environmental footprint is smaller.
• Scientists say it's not really possible to shrink people "at the cellular level" like this, but there are real ways to make humans smaller that could help offset carbon emissions. 

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No matter what Matt Damon does in the movies, you can't actually shrink yourself down to 5 inches. 

The producers of the new film "Downsizing" admit they had to ignore a lot of science to tell the story of a future where people elect to get much smaller in order to live large. The movement starts when a Norwegian scientist discovers a novel way to miniaturize people, in a move he hopes will save humanity by reducing the amount of waste and pollution humans produce. And the little life is cheaper, too.

In the film's downsized world, a "conflict free" diamond ring and necklace set costs just $83, which is about twice the amount a "small" family spends on groceries each month. And the steakhouse chain Tony Roma's has also been shrunk and imported to the land of the small.

Screenwriter Jim Taylor bluntly put the kibosh on anyone's dreams of living in a cheap, small world like this after a screening of his movie at the Museum of the Moving Image.

"It's never going to happen," Taylor said. 

In the movie, Matt Damon's character works at a call center, but in reality his tiny voice would be way too high-pitched to answer calls from the world of normal-sized folks. Plus, at roughly the height of an iPhone 6, he'd likely be small enough to get swept away by a strong gust of wind. And the mini humans in the movie mostly ignore the huge risk that the protective net around their colony could rupture, allowing a runaway cat or a street rat to gobble them up.

But NYU bioethicist S Matthew Liao, who joined Taylor for the post-screening discussion, has highlighted some very real ways that shrinking people down — though to levels much less drastic than in the film — could help mitigate the effects of climate change.

In a 2012 paper in the journal Ethics, Policy & Environment, Liao spelled out a few of his ideas, which he said could be less risky than other last-resort options like geoengineering.

One idea Liao pushed for is to shrink people back down to the 15-centimeter-shorter heights of humans like Albert Einstein who lived 100 years ago. 

"It turns out that 15 centimeters of reduction in height translates to around 23% mass reduction for men and 25% mass reduction for women," Liao said during the talk. He believes that's "enough to offset the effects of climate change."

Technology that could hypothetically make this shrinking process possible is already in use in fertility clinics. It's called "preimplantation genetic diagnosis" and it allows future parents to screen out embryos that have genetic diseases. With around 500 genes coding for height, Liao says, "that's a way you can actually select embryos for size."

Of course, it doesn't take much mental leap to realize some of the ethical problems that selecting embryos for size, among other traits, would quickly create.

Another possible way to shrink people would be to give them extra estrogen. This technique has been used in kids with profound developmental disabilities to keep them small enough for their parents to continue taking care of them as they grow up. 

While such ideas might seem draconian, Liao said there's no denying the effects that taller people have on the planet. 

"It takes more energy to transport a larger person than a smaller person," he said, adding that making humans smaller could also come in pretty handy if we decide to colonize Mars.

"To get off the planet, size is going to matter a huge deal," Liao said. "Just think, per person, how much resources you need to sustain people in space." 

Many of us would probably never opt to give up our 21st-century height boost, no matter how warm the planet gets. But it does seem like the change could offer more benefits than we realize.

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