Here’s what would happen if all the ice on Earth melted overnight

  • If all the ice on Earth melted overnight, the planet would be sent into chaos.
  • There would be mass flooding from sea levels rising, severe weather changes, deadly chemical releases, and mass greenhouse gasses that would leak into the atmosphere.
  • Scientists say we need to stop the planet from rising in temperature by just 1° Celsius, or this could happen sooner than we think.
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Following is a transcript of the video.

Narrator: Ninety-nine percent of all freshwater ice on Earth is sitting on top of Greenland and Antarctica, and each year, a little more of it melts into the ocean. Normally, it would take hundreds to thousands of years for it all to melt away. But what if something happened that caused a massive global melt overnight?

As we slept, sea levels would rise by a whopping 66 meters. Coastal cities like New York, Shanghai, and London would drown in the apocalyptic mass flood, forcing up to 40% of the world’s population out of their homes. While all this chaos ensues aboveground, something equally sinister is happening below. All that rising saltwater will infiltrate groundwater reserves farther inland, forcing its way into nearby freshwater aquifers. You know, the ones that supply our drinking water, irrigation systems, and power-plant cooling systems? All those aquifers would be destroyed. Not good.

On top of that, the ice on Greenland and Antarctica is made of freshwater, so when it melts, that’s about 69% of the world’s freshwater supply that’s going straight into the oceans. This will wreak havoc on our ocean currents and weather patterns. Take the Gulf Stream, for example. It’s a strong ocean current that brings warm air to northern Europe and relies on dense, salty water from the Arctic in order to function. But a flood of freshwater would dilute the current and could weaken or even stop it altogether. Without that warm air, temperatures in northern Europe would plummet, and that could spawn a mini ice age, according to some experts.

That’s not even the worst of it. Take a look at what will happen when that last 1% of freshwater ice that’s not part of Greenland or Antarctica thaws. Some of that 1% is sitting in glaciers farther inland. The Himalayan glaciers specifically pose one of the largest threats because of what’s trapped inside: toxic chemicals like dichlorodiphenyltrichloroethane, or DDT. Scientists discovered that glaciers like this can store these chemicals for decades. But as they thaw, those glaciers release the chemicals into rivers, lakes, and groundwater reserves, poisoning each one as they go.

The rest of that 1% is hanging out underground, mostly in the Arctic tundra, as something called permafrost. Permafrost is organic matter that’s been frozen in the ground for two-plus years. Now, one of the most immediate problems with thawing permafrost would be mercury poisoning. That’s right: There are an estimated 15 million gallons of mercury stored up in the Arctic permafrost. That’s almost equal to the amount of mercury everywhere else on Earth. On top of that, the organic matter in permafrost is a tasty meal for microorganisms. After they digest it all, they fart out two of the most potent greenhouse gases out there, carbon dioxide and methane. Scientists estimate this could double the current levels of greenhouse gases in the atmosphere, and potentially cause global temperatures to rise by 3.5 degrees Celsius compared to today.

That might not sound like much, but say goodbye to that mini European ice age, and even rivers and lakes around the world. They’d evaporate from the higher temperatures and cause mass droughts and desert-like climates. And all that extra water vapor in the atmosphere would fuel more frequent and stronger storms, floods, and hurricanes. So all of that newly established coastline on the eastern US would be one of the last places you’d want to live. Instead, there would be mass migrations to Canada, Alaska, the Arctic, and even what’s left of the Antarctic.

And you’re right, this is probably never going to happen. After all, there’s enough ice right now to cover the entire continent of North America in a sheet a mile thick. So the next time you hear about record-breaking heat or ultra-powerful hurricanes, at least you know that it could be worse. But scientists estimate that if we don’t take action and global temperatures increase by just 1 degree Celsius, the effects of climate change we already see today will be irreversible. So yes, it could be worse, and it will be if we’re not careful.

EDITOR’S NOTE: This video was originally published in September 2019.

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An iceberg the size of Los Angeles just broke off Antarctica – and it could happen again within weeks

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A view of the North Rift crack on the Brunt Ice Shelf in February 2021.

Antarctica’s Brunt Ice Shelf is replete with giant cracks. 

Scientists have been keeping tabs on the capricious ice for years, and the event they’d been watching out for finally happened on Friday: An iceberg more than 490 square miles (1,270 square kilometers) in size splintered off the shelf. It’s about the size of Los Angeles, and more than 20 times the size of Manhattan. 

The Brunt Ice Shelf is located on Antarctica’s northern rim, some 3,000 miles from the southernmost tip of South America. It has all the key ingredients for a massive calving event – the term for when a chunk of ice breaks off and floats out to sea. The British Antarctic Survey (BAS), had warned since November that the event was “imminent,” since a crack called the North Rift had opened up on the shelf. 

In January, the rift started lengthening by more than half a mile per day. The video below shows the crack from the air.

Early on Friday, the last 1,000 or so feet (a few hundred meters) of the crack tore through the ice, and the ‘berg cracked free.

Converging cracks in the ice

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The North Rift crack in the Brunt Ice Shelf, as seen from the air on January 12, 2021.

The North Rift is the third major crack to develop on the Brunt Ice Shelf since 2011, according to the BAS, which keeps tabs on the region’s ice using satellite imagery.

But this one wasn’t the crack that had researchers concerned. Two other cracks have been accelerating toward each other since 2019, known as the “Halloween crack” and “Chasm 1.” If  those meet, an even bigger iceberg will slough off into the ocean. 

“It seemed as though one of these would eventually lead to a calving event,” Adrian Luckman, a glaciologist at Swansea University in Wales, told Insider. “The development of a new ‘North Rift’ towards the end of 2020 was a bit of a surprise but shows how complex the dynamics of ice shelves can be.”

NASA started tracking the Halloween crack in October 2016 (hence its name). It’s growing eastward from an area called McDonald Ice Rumples – a spot on the shelf’s surface where the ice isn’t flat and instead features crevasses and rifts.

The “Chasm 1” crack is located southeast of the McDonald Ice Rumples and started showing signs of movement in 2012. It started accelerating north in 2019, putting it on a collision course with the Halloween crack. The two are now just 1.2 miles (2 kilometers) apart.

Brunt Ice Shelf cracks
A map shows cracks on the Brunt Ice Shelf and the British Antarctic Survey’s Halley VI research station, February 26, 2021.

When they converge, a piece of ice about 660 square miles in size could break off the ice shelf.

According to the BAS, neither Chasm 1 nor the Halloween Crack have grown in the last 18 months. But Luckman, who’s been tracking the Brunt Ice Shelf cracks over the past few weeks using satellite imagery, thinks that quiet period is at an end. 

“Chasm 1 will certainly give rise to a further large calving event and I anticipate that this will happen in weeks to months,” he said.

The changing ice forced British researchers inland

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The North Rift crack in the Brunt Ice Shelf, as seen from the air on January 12, 2021.

This isn’t the first time Antarctica has lost a giant iceberg, and it didn’t set any records for size. In 2017, an iceberg the size of Delaware broke off the continent’s Larsen C Ice Shelf. 

“It is entirely natural for sections to calve away from ice shelves. As ice flows off the land, the ice shelf grows and eventually reaches a size which is unstable,” Luckman said. “Some calving events are small and go unnoticed, but every few years, a large one such as this happens.”

It’s difficult for scientists to determine how and why certain cracks in the Antarctic ice suddenly begin to grow, and there’s “no evidence that climate change has played a significant role,” the BAS said in a press release

Still, research shows that warming oceans are speeding up Antarctica’s melting overall. In the 1980s, Antarctica lost 40 billion tons of ice annually. In the last decade, that number jumped to an average of 252 billion tons per year

The instability of the ice has already impacted BAS researchers working at the Halley Research Station, where scientists study space weather and Earth’s atmosphere. In 2017, the expansion of Chasm 1 forced scientists to prematurely end the winter research season at Halley and close the station early

Since the station’s inception in 1956, there have been six Halleys. The station’s current iteration, Halley VIa, moved 14 miles upstream from its original location, which had been to the west of Chasm 1, on the crack’s inland side. 

“Four years ago, we moved Halley Research Station inland to ensure that it would not be carried away when an iceberg eventually formed. That was a wise decision,” Simon Garrod, director of operations at BAS, said in the release. “Our job now is to keep a close eye on the situation and assess any potential impact of the present calving on the remaining ice shelf.”

BAS Halley Research Station 10010653(Karl Tuplin BAS)
The British Antarctic Survey’s Halley VI research station on the Brunt Ice Shelf.

Luckman said he doesn’t think future calving events will pose a threat to the research station.

“Halley VI is on a stable part of the ice shelf,” he said. “But as we have seen, the future behaviour of fracturing ice is very hard to predict.” 

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