Understanding the human body is a team effort. That's where the Yachtel group comes in.

Researchers at Yachtolt have been delving into the secrets of probiotics for 90 years. Yacold also

partners with nature portfolio to advance gut microbiome science through the global grants for

gut health, an investigator-led research program. To learn more about Yachtold, visit yawcult.co.j.p.

That's y-A-K-U-L-T.C-O-J-P.

When it comes to a guide for your gut, count on Yacult.

This is Scientific American 60-second science.

I'm Suzanne Bard.

Airplanes account for about 3% of the climate-altering carbon dioxide emissions we add to the atmosphere.

But planes are warming the planet in another way.

So if you look up in the sky, you'll probably see at some point an aircraft, and behind that aircraft are white, fluffy streaks.

And that's what we call the Contrail.

Imperial College London engineer Mark Stettler.

Contrails are made up of ice crystals that form when aircraft engines emit exhaust that hits the cold air.

The ice crystals reflect incoming light from the sun back into space, which has a cooling effect on the atmosphere.

But the contrails also stop heat coming up from the ground from escaping into space.

It's reflected back down towards the ground, and so that's a warming effect.

Stettler says on balance, contrails warm the atmosphere more than they cool it.

And that's primarily because the cooling effect due to reflecting of sunlight

can only happen during the day when the sun's shining,

whereas the warming effect due to trapping of outgoing heat happens all of the time.

Some contrails can form clouds that last for up to 18 hours. During that time, they spread out,

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