Here's What Would Happen If The Oceans Froze Over

According to Smithsonian Magazine, the Earth has completely frozen over at least twice in its history — some geologists say as many as four times. The so-called "snowball Earth" was admittedly pretty to look at — sort of like a giant Christmas ornament hurtling through space — but it wasn't a great place to live. In fact, the only surviving life on the planet was colorfully described as "pond scum."

Fortunately for those of us who enjoy existing as multicellular organisms and not freezing to death, the most recent iteration of "snowball Earth" was about 650 million years ago, and the planet (obviously) warmed up into the balmy, Dollywood-having place we all know and love today. But how did it happen? Could it happen again? And if it did ... could we fix it? Read on for the answer to these questions and many more.

To be clear, no one knows for sure what made the Earth so cold in the past. Ray Pierrehumbert of the University of Chicago (quoted in Smithsonian) says it could have been a meteorite throwing dust and ash into the atmosphere and blocking the sun, but that scenario seems unlikely to have happened more than once. It's also possible that "snowball earth" is just part of the planet's natural carbon cycles — greenhouse gases drop, the Earth gets cold.

We can get the obvious stuff out of the way first: It would be cold. We're talking something in the neighborhood of 58 degrees below zero, and the temperature would actually keep dropping since a frozen ocean would reflect more sunlight back into space than a liquid one. The ice on the Earth's surface would be up to 1 kilometer thick, and even in the tropics, it would still be 10 meters thick. The What If Show helpfully points out that while people who live in colder climates might be prepared to deal with the temperature drop, people who have never owned winter gear would be out of luck, barring a surprise delivery from the Burlington Coat Factory.

Maybe less obviously, frozen oceans would mean that all industry would die. Huge amounts of global shipping — including about half of all petroleum shipping — is done by sea (via Science Focus). With the oceans frozen, oil prices would skyrocket and trade would grind to a standstill.

To continue with that "frozen oceans kill things" theme, all life in the ocean would die out as well. The algae would be unable to survive under the ice, and the bad news would just travel up the food chain from there, with all animals that depend on the ocean to survive eventually kicking off. And eventually, all life on land would die as well thanks to the lack of liquid water.

If there's an upside to that angle, it's that with the plant life gone, there would be nothing to trap greenhouse gases, and a global warming cycle would commence. So in that sense, the problem would just fix itself — in a few hundred million years. But hey, you're patient, right?