00:00Salt makes our chips and popcorn taste yummy, but it turns out that's not all.
00:05It's used in household and industrial products, from cosmetics to fertilizers, from water
00:11treatment to road gritting.
00:13All over the globe, around 300 tons of salt are produced every year.
00:19But there's a problem.
00:20That's too much salt for our planet.
00:22You see, salt rises to Earth's surface from deep oceanic rocks gradually, and this process
00:28is quite balanced, or it used to be.
00:32Humans are pushing this balance out of whack.
00:34Our demand keeps increasing, and we're releasing too much salt into the soil, air, and sea.
00:40And if this process continues unchecked, we might face an existential threat.
00:45Yep, it's as serious as that, and a recent study conducted by the University of Maryland
00:51confirms this.
00:52There is this thing called the natural salt cycle.
00:56It's existed for thousands of years.
00:58Salt naturally rises to our planet's surface via geologic uplift and rock weathering.
01:05Some time later, rocks break down and release salt ions into the soil.
01:10Some of these ions are absorbed by plants and organisms.
01:13Others are washed away into rivers, which transport them into oceans.
01:17Salt also gets into the atmosphere.
01:20It happens through salt dust in dry regions and sea spray in coastal areas.
01:26It's crucial for humans because our bodies need salt, just like animals and plants do.
01:32Simply put, we're electrical systems controlled by salt.
01:36Soil needs salt because otherwise it won't clump together.
01:40Plants also need small amounts of salt since those allow them to have proper metabolism
01:45and synthesize enough chlorophyll.
01:48At the same time, too much salt isn't a great thing, and nowadays human activity is messing
01:54with the natural salt cycle, bringing salt to the planet's surface much more quickly
01:58than before.
01:59That's the conclusion researchers made after combining data from different sources, including
02:04the U.S. Geological Survey's Mineral Yearbook and Global Records of River Compositions and
02:10Salinity Measurements.
02:12The main factor bringing about these changes is salt mining for food and other products.
02:18Then there are also acid rains.
02:20Those increase the rate of rock weathering.
02:24These and other factors speed up the generation of salt at the surface of our planet.
02:29At the moment, the concentration of salt in the world is too high.
02:33The soil, plants, and animals can't use all of it.
02:36Even worse, some essential species can't survive with all this extra salt.
02:42Their demise changes biodiversity and can lead to the appearance of invasive species,
02:47such as phragmites.
02:49Those are tall, riddy plants taking over coastal areas.
02:53Then there's also zooplankton, an important ocean species regulating algae.
02:59It's extremely sensitive to salt.
03:01If this species starts to decline, it might mess with the world's food webs.
03:06Too much salt also turns farmlands into wastelands.
03:11Recent reports have shown that around 833 hectares of land are already affected.
03:17And that's the area around four times the size of India.
03:21In some countries, huge areas become infertile because of over-salination.
03:27Plus excess salt is bad for our health.
03:30The thing is, all that extra salt gets into groundwater, making it too salty for human
03:35consumption.
03:36It's particularly bad for people with sodium-restricted diets.
03:40And I'm not only talking about table salt or sodium chloride.
03:44No, other calcium and magnesium-based salts are seeping out too, usually from the production
03:50of fertilizers and building materials.
03:53It's like a chemical cocktail of different salts coming from various sources.
03:58And scientists don't know yet the effects such a cocktail can have on us humans and
04:03our health.
04:05So maybe now you're sitting and thinking, oh, it's time to cut back on my salt intake.
04:11Perhaps, but don't cut it all out.
04:14In the 1930s, Dr. Robert McCants from Cambridge University's Department of Experimental Medicine
04:20found four volunteers and asked them to go 10 days completely without salt.
04:25First, they had to sweat out the salt that still remained in their bodies.
04:29And after that, the scientists literally desalinated everything they were allowed to eat and drink.
04:36Soon after, the participants started to experience weird sensations.
04:40They realized that they didn't taste much flavor in anything they consumed.
04:45It got worse.
04:46Fatigue set in, and the volunteers soon got too tired to even eat.
04:51They began to show the signs of hyponatremia.
04:54It occurs when the concentration of sodium in your blood is dangerously low.
04:59And that's when a person's blood cells swell because there's not enough salt in the blood
05:04to regulate how much water a cell should and will consume.
05:09If this condition is left untreated, it can not only result in seizures but also have
05:14much, much worse consequences.
05:17At the end of the trial period, participants got some salty foods, and miraculously, within
05:22a few minutes, they could taste again, and their energy seemed to be replenished almost
05:27immediately.
05:28Honestly, it sounds kind of terrifying.
05:32If that's what a mere 10 days without salt are, imagine what catastrophe it would be
05:37if salt just ceased to exist.
05:39We wouldn't be able to last long, that's for sure.
05:42And it would be a never-ending drama not only for us but for plants and animals, too.
05:48They need salt as much as we do.
05:50If our oceans suddenly lost all the salt, it would wipe out all underwater algae, cutting
05:55photosynthesis on Earth almost in half.
05:59Land-based plants would follow suit.
06:01So, soon after the disappearance of salt, we'd face a huge issue.
06:06Too much carbon dioxide and not nearly enough oxygen.
06:10Our climate would start fluctuating between extremely hot and cold temperatures, and hurricanes
06:15would become insanely powerful and super destructive.
06:19Luckily, we still have salt at our stores and the natural salt cycle might get more
06:24or less stable again.
06:26By the way, humanity has known of and appreciated salt for many centuries.
06:31For example, it was used as offerings and to preserve mummies in ancient Egypt.
06:36It was a valuable commodity, traded between the Phoenicians and their Mediterranean empire.
06:42In ancient China, people knew of more than 40 types of salt and used it for medicinal
06:47purposes.
06:49In medieval continental Europe, Venice gained power through its salt monopoly.
06:54The production and transportation of salt led to the appearance of new cities and the
06:59construction of roads.
07:01Salzburg, the city of salt in Austria, is a great example of that.
07:07Even these days, salt continues to surprise us.
07:10For example, recently, researchers from the University of Miami Rosensteil School of Marine
07:15and Atmospheric Science have discovered rare deep-sea brine pools in the Gulf of Acaba.
07:22That's a northern extension of the Red Sea.
07:25Those salty underwater lakes are likely to hold secrets about the way oceans on Earth
07:30formed all those millions of years ago.
07:33They might also give us some clues to life on other planets.
07:38Brine pools are some of the most extreme environments on Earth.
07:41And still, despite their ultra-high salinity, somewhat exotic chemistry, and total lack
07:46of oxygen, they're teeming with life.
07:50Researchers have even found bioactive molecules with potential anti-cancer properties in brine
07:56pool microbes in the Red Sea.
07:59These super-salty, zero-oxygen brine pools are located close to the coast and might preserve
08:04information on tsunamis, earthquakes, and flash floods that took place in the Gulf of
08:09Acaba thousands of years ago.
08:13Salt has even made its way into space!
08:15Well, kind of.
08:16You see, the Moon is like a comet soaring through the cosmos.
08:20Our natural satellite is followed by a slender tail consisting of irradiated matter, and
08:25our planet passes directly through this tail once a month.
08:29Well, according to a study published in the journal JGR Planets, this lunar tail is made
08:35of millions of sodium atoms.
08:38And as you already know, the chemical formula of salt is sodium chloride.
08:44Those atoms get blasted out of the lunar soil by meteor strikes and then pushed thousands
08:49of miles downstream by solar radiation.
08:53For several days a month, when the new Moon is located between Earth and the Sun, the
08:57gravity of our planet drags that sodium tail into a long beam which wraps around our planet's
09:04atmosphere.
09:05The tail itself is harmless and invisible to the unaided eye, but during those new Moon
09:10days, high-powered telescopes can detect the faint orange glow of sodium in the sky.
09:16That's it for today!
09:17So hey, if you pacified your curiosity, then give the video a like and share it with your
09:21friends.
09:22Or if you want more, just click on these videos and stay on the Bright Side!
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