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A new and unexpected pattern is emerging in Earth’s climate, and it has scientists deeply concerned. One half of the planet is cooling faster than ever recorded, creating an imbalance that could trigger widespread and unpredictable consequences. What’s causing this rapid shift—and what it means for the rest of the world—is only just beginning to come into focus.
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00:00Earth isn't a perfect ball, we know that.
00:03But the real mystery is miles beneath our feet.
00:06Way down below the crust, the planet has been cooling down for billions of years, just not evenly.
00:12The Pacific side loses heat faster, while the African side slows that loss by trapping it longer.
00:19That difference is why Earth stays restless, with earthquakes tearing the ground apart and volcanic fire breaking through the surface.
00:28Think of Earth like a massive engine that's been shut off.
00:31The outside cools first, but deep inside, heat lingers.
00:35That internal heat is leftover energy from when the planet formed, and it's been slowly trying to escape ever since.
00:42For a long time, scientists assumed Earth lost heat evenly in all directions.
00:47Hot in the middle, slowly cooling everywhere else.
00:50But when a team at the University of Oslo ran simulations that rewound the planet 400 million years and tracked
00:57where the heat actually escaped, they saw something very different.
01:01The cooling wasn't symmetrical at all.
01:04One side of the planet is doing it faster than the other.
01:07The difference is striking.
01:09The Pacific hemisphere, the side dominated by the world's largest and deepest ocean, has cooled by about 50 degrees Kelvin,
01:17which is roughly 90 degrees Fahrenheit difference, compared to the Africa-Eurasia side.
01:23The reason is basically insulation.
01:26Africa and Eurasia are on a layered ancient continental crust.
01:30The Pacific side is the opposite.
01:32It's mostly ocean, resting on a much thinner crust where warmth escapes easily.
01:37Plus, the cold seawater on top pulls that heat out non-stop.
01:42Because the Pacific side is cooling so fast, the rock deep underground is getting heavy and sinking back toward the
01:50core.
01:50It's like a giant slow-motion conveyor belt that drags the Earth's crust down with it.
01:55Heavy materials sink.
01:57As it sinks, it pulls on the edges of tectonic plates, creating stress, trenches, earthquakes, and chains of volcanoes.
02:06Most of Earth's earthquakes and volcanoes happen in a giant loop called the Ring of Fire.
02:12This is where the ocean floor gets cold, heavy, and sinks deep into the planet.
02:17All that sinking rock travels thousands of miles down until it slams into a massive continent-sized structure sitting right
02:25near Earth's core.
02:27Scientists call this a blob because the heavy ocean floor is constantly falling on top of it.
02:33The Pacific blob is squashed flat and pinned down, sitting heavy and locked in place.
02:39But the other half of the world is doing the exact opposite.
02:42Under Africa, there aren't many sinking plates to act as a weight.
02:46Without that pressure holding it down, the African blob is free to grow tall and light.
02:52It pushes upward, lifting the ground from below and reshaping the entire continent.
02:57In fact, that rising bubble is already starting to tear the surface apart.
03:02In East Africa, a massive crack known as the Great Rift Valley is slowly opening up as the ground is
03:09pushed from below.
03:11Eventually, the pressure will become so high that Africa will literally split in two, allowing a brand new ocean to
03:19rush into the gap.
03:21There's a cool theory that suggests these blobs might actually be the remains of an ancient planet named Theia.
03:28Some researchers believe that Theia crashed into Earth billions of years ago.
03:32And while part of it broke off to form the Moon, some heavy chunks might have sunk deep inside our
03:38planet.
03:39So, the reason our interior is so lopsided might be because we literally have pieces of a different world buried
03:47inside our own.
03:48But that's just a wild theory.
03:50Whatever their origin, the blobs matter because they help split the planet into two different behaviors.
03:56On the Pacific side, cold slabs keep sinking down and piling up.
04:00On the opposite side, heat builds up deep and pushes upward over time.
04:04One half is dominated by downward motion, the other by upward motion.
04:10And this imbalance doesn't stop at the mantle.
04:13It shows up at the very center of the planet because Earth's inner core is still growing.
04:18Liquid iron around it gradually turns solid and attaches to the core.
04:23This process doesn't progress at the same rate everywhere.
04:27One side of the inner core builds up faster than the other.
04:30This might sound like it should throw the planet off balance, but it doesn't.
04:35Earth's interior isn't rigid like a solid metal ball.
04:39Over time, stuff inside can gradually move around.
04:42Gravity pulls everything toward the center, helping everything get a bit smoother and keeping the core pretty round.
04:49But pretty round doesn't mean perfect.
04:51If you want a real example of how uneven Earth is on the inside, look at the Indian Ocean.
04:58Where there's more mass underground, gravity pulls a little harder.
05:03Where there's less mass, it pulls less.
05:05In the middle of the Indian Ocean, there's a huge anomaly called the Indian Ocean Gravity Hole.
05:11In that spot, Earth's pull is weaker than normal, so weak that it can't hold the ocean's surface up at
05:18the usual level.
05:18The water actually dips downward.
05:22You wouldn't notice it sailing through, but you'd technically be sitting about 300 feet lower than the rest of the
05:28world's oceans.
05:29It's an invisible valley in the sea, caused entirely by missing mass deep inside the planet.
05:36However, Earth isn't the only world hiding a messy interior behind a smooth surface.
05:42Even the Moon is like this.
05:43Over billions of years, Earth's gravity slowed the Moon's rotation until it locked into place, keeping one face permanently pointed
05:52toward Earth.
05:53That's what we know as the nearside and the far side.
05:57This mattered early in the Moon's history.
05:59The nearside always faced Earth, while the far side always faced deep space.
06:05That long-term setup affected how heat was stored and released inside the Moon.
06:10When NASA mapped the Moon's gravity using two spacecraft called GRAIL, they measured something called the love number.
06:17It's a value that tells scientists how much a planet or Moon flexes under gravity.
06:22The Moon's love number turned out higher than expected, which meant its interior was softer than it should be.
06:29When scientists looked closer at the gravity data, they found that most of this flexibility came from the side facing
06:36Earth.
06:38The Moon's nearside is softer and warmer deep down, while the far side is cooler and more rigid.
06:44Measurements suggest the nearside mantle is significantly hotter and more volcanic.
06:49That difference shows on the outside.
06:52Because the nearside was so hot and soft, ancient lava could easily punch through the crust and flood the surface.
06:58That created those big dark patches we see at night.
07:01On the other hand, the far side stayed colder and stiffer, so the lava never flowed the same way.
07:08Back on Earth, the Pacific has another quirk worth mentioning.
07:13Our planet isn't just spinning in place.
07:15It orbits the Sun at over 66,000 miles per hour, and the entire solar system is moving through the
07:21galaxy like a car driving through a swarm of bugs.
07:24Over long periods of time, objects drifting in from deep space are more likely to hit the side of Earth
07:31that's moving forward.
07:32And because the Pacific Ocean covers such a huge stretch of that side of the planet, it naturally ends up
07:38catching more impacts than smaller oceans or continents.
07:41This creates a strange coincidence.
07:45The same hemisphere that is leaking the most heat from within is also the world's biggest graveyard for things arriving
07:51from the outside.
07:53Because it is so vast and lonely, space agencies even use its most remote coordinates as a spacecraft cemetery at
08:01a spot called Point Nemo.
08:03We deliberately aim satellites and massive space stations like Mir to crash right there.
08:08So, the Pacific ends up taking the hits from two directions, by accident, from the universe, and on purpose, from
08:16us.
08:16Earth is restless, continents drift, oceans open and close.
08:22In a few hundred million years, the map will look completely different.
08:25The Pacific is actually shrinking right now.
08:28Eventually, the Americas might crash into Asia, and a new ocean will have to take over the job of being
08:34the planet's main radiator and its front bumper.
08:37But for now, we should probably be thankful for that massive, chilly, unlucky ocean.
08:46Put on your woolen hats, find the warmest mittens, and go buy the thickest blankets.
08:51The next ice age might be just around the corner.
08:55And the trigger is much more shocking than anyone might have expected.
08:59What's even worse?
09:00We have no control over our bitterly cold future.
09:06Earth's climate has been on a wild ride for millions of years.
09:09It's been warming up, freezing over into ice ages, then heating up again to the more normal temperatures we know
09:16today.
09:17These cycles, called quaternary ice ages, are part of a much longer pattern of global freezing and thawing.
09:24For a long time, scientists thought Earth's orbit around the sun had something to do with triggering ice ages.
09:31But figuring out exactly how was tricky.
09:34Well, new research has finally connected the dots.
09:37It shows how tiny changes in Earth's tilt, wobble, and orbit mess with the growth and melting of huge ice
09:45sheets.
09:47This is a pretty big deal, because it helps scientists understand not just what happened in the past, but also
09:53what might happen to our climate in the future.
09:57Even small shifts in how Earth moves through space can have huge effects over thousands of years.
10:03These changes control how much sunlight different parts of the planet get, which affects how ice sheets grow and shrink.
10:11Earth doesn't orbit the sun in a perfect circle.
10:14It actually follows a slightly oval-shaped path.
10:18This phenomenon is called orbital eccentricity.
10:21Since the sun isn't sitting right in the center of this oval, Earth's distance from it changes throughout the year.
10:29Plus, the oval itself slowly shifts position in space over time, which is called orbital precession.
10:35On top of that, Earth's tilt, a.k.a. obliquity, also changes slightly as our planet moves around the sun.
10:45Scientists have known for a while that these orbital quirks impact our planet's climate, causing cycles of warming and cooling.
10:52As different parts of Earth's orbit shift, they change how sunlight is distributed across the planet, influencing seasons and ice
11:00ages.
11:01These Milankovitch cycles happen roughly every 20,000, 40,000, 100,000 and even 400,000 years.
11:11The difficult part is to figure out how each of these orbital changes affects climate shifts.
11:17Earth's climate is a complicated system, with tons of factors influencing it at the same time.
11:24Modeling all these processes is no easy task.
11:27It needs huge computing power and a deep understanding of each factor's role in shaping our planet's past and future
11:34climate.
11:36There are two cycles that are super close to each other in timing.
11:40Precession, which happens every 21,000 years.
11:44And the second harmonic of obliquity, that happens at 20,500 years.
11:50But even though they're so close, no one has been able to directly connect either of these cycles to the
11:55end of an ice age.
11:57On top of that, for the past 800,000 years, ice ages have ended every 100,000 years.
12:04And scientists still haven't figured out what causes this pattern.
12:08To get to the bottom of it, researchers turned to the deep sea.
12:11They studied changes in oxygen isotope ratios found in the tiny, fossilized shells of marine creatures.
12:19These tiny creatures live in the ocean, and their exoskeletons preserve clues about past climate.
12:26Specifically, changes in ice sheets.
12:29This allowed the researchers to track the beginning and end of ice ages over the past 800,000 years.
12:36By comparing the changes in the ice sheets with Earth's orbital changes, they found an incredible pattern.
12:43The key moments when Earth moved between ice ages and warmer periods were perfectly lined up with specific relationships between
12:50precession and obliquity.
12:52It turns out that the end of an ice age, called deglaciation, is closely linked to the way precession and
12:59obliquity align.
13:00But it's obliquity alone that seems to trigger the start of an ice age.
13:05This discovery is the key to understanding the 100,000-year cycle of ice ages.
13:11The researchers say it was always there, just waiting to be noticed.
13:16Before the discovery, people thought the timing of ice ages was more random.
13:21But this new study shows there's a clear, predictable pattern.
13:26This means we might actually be able to predict when ice ages will happen in the future.
13:33Right now, Earth's tilt is slowly decreasing, and in about 11,000 years, it'll hit its lowest point.
13:40Based on the team's calculation, the next ice age is expected to begin before then.
13:46At the same time, according to the latest reports, humans have already started pushing Earth's climate off its natural path
13:53by releasing greenhouse gases.
13:56Another thing scientists are warning about is a massive shift that's happening in the Atlantic Ocean, and it could drastically
14:04change the world's climate.
14:06The Atlantic meridional overturning circulation is a system of ocean currents that moves warm and cold water around the planet.
14:14And right now, it is showing signs of weakening.
14:18What will happen if it collapses?
14:21Freezing temperatures in Europe, extreme weather across the world, shifting monsoons, and even an Amazon rainforest drying up.
14:30And the scariest part?
14:31Some researchers say there's a 95% chance this could happen before the end of the century.
14:37Think of the AMOC like a giant conveyor belt in the ocean.
14:42Warm, salty water from the tropics flows north towards Europe and North America.
14:48When it reaches colder areas, it cools down, becomes heavier, and sinks to the bottom of the ocean.
14:54This deep, cold water then moves southward, while fresh, warm water from the equator keeps flowing north to replace it.
15:02This system helps regulate global temperatures, keeps Europe's winters mild, and prevents the U.S. east coast from flooding.
15:10It also controls monsoon patterns that bring seasonal rain to parts of Africa, South America, and Asia.
15:18Without it, the world's climate would look completely different.
15:21Right now, melting ice from Greenland and Antarctica, along with increased rainfall and river runoff, is dumping too much freshwater
15:29into the North Atlantic.
15:32Since freshwater is lighter than seawater, it disrupts the sinking process that keeps the AMOC moving.
15:39If too much freshwater builds up, it will mess up the entire system.
15:43And once it collapses, there will be no reversing it, even if the climate later cools down.
15:51Scientists have seen two big warning signs.
15:53First of all, the warming of the ocean off the U.S. east coast, which suggests the AMOC is already
16:00slowing down.
16:02Plus, there's a cold blob of water south of Greenland.
16:06It might be a sign of the weakening of the ocean current.
16:09And that's exactly what happens before the system fails.
16:14What would happen if the AMOC fully shut down?
16:20The AMOC plays an important role in keeping Europe's winters relatively mild by bringing warm water north.
16:28If this process stopped, Europe would be plunged into deep winter.
16:33London's climate would drop by 18 degrees Fahrenheit, making it feel like northern Canada.
16:39Stockholm could get up to 54 degrees Fahrenheit colder, turning it into Siberia-like conditions.
16:45And snow and ice would cover much of northern Europe year-round.
16:52Next, monsoons would shift, leading to severe droughts.
16:57The AMOC helps regulate tropical rainfall, especially in Africa, South America, and Asia.
17:03If it collapsed, West Africa's monsoons would shift or disappear, leading to devastating droughts and a massive food crisis.
17:12The Amazon rainforest could dry up, transforming into a savannah or grassland.
17:19In India and Southeast Asia, monsoon rains would disappear, and millions of people rely on them for agriculture.
17:27The U.S. East Coast could see catastrophic flooding.
17:31With the AMOC weakening, water is already piling up along the U.S. East Coast, triggering higher sea levels and
17:37stronger hurricanes.
17:39If the system shut down, sea levels would rise by up to 3.2 feet, which would make the coastal
17:46cities more vulnerable to flooding.
17:49Finally, hurricanes and extreme storms could become even more powerful because of warmer waters along the coast.
17:57Now, how close are we to disaster?
18:00For thousands of years, the AMOC has remained stable, but recent studies suggest it's weaker now than at any point
18:08in the past 1,600 years.
18:11Ocean temperatures are hitting record highs, and many researchers believe we are dangerously close to the tipping point.
18:18A study published in Nature claims that if greenhouse gas emissions continue at their current pace, there's a 95%
18:26chance that the AMOC will collapse before 2100.
18:33Did you know that the Pleistocene era was a really important time in Earth's history?
18:39It's when the last Ice Age happened, and glaciers covered a lot of the planet.
18:43This period of time lasted for about 2.6 million years, and ended around 11,700 years ago.
18:51What's even cooler is that modern humans, like us, had actually evolved during this time, and had spread all over
18:59Earth before it ended.
19:01There were also some really fascinating animals that lived during the Pleistocene, like woolly mammoths and saber-toothed cats.
19:11Unfortunately, many of them went extinct at the end of this era.
19:16Earth has had some pretty wild weather patterns over the last 2.4 billion years.
19:21Although the planet is mostly ice-free, we now cycle in and out of freezing ice ages.
19:27During these glacial periods, temperatures drop, and huge areas of the planet get covered in ice.
19:34It all starts with a bit of snow, which then builds up over time.
19:38The ice reflects sunlight, making things even cooler.
19:42The result? Vast glaciers that slowly move toward the equator, changing the landscape as they go.
19:49And when the ice melts, sea levels rise again, and everything changes all over again.
19:56In total, there have been at least 5 ice ages so far.
20:01The first one was so intense that the whole planet turned into a huge snowball.
20:07Right now, we're actually in the middle of an ice age.
20:10But we're currently in a temporary warm spell that started around 11,000 years ago.
20:16These warm periods are called interglacials, and we're not quite sure how long they last.
20:23There are still massive ice sheets covering Antarctica and Greenland that hold 75% of Earth's fresh water.
20:30When these finally melt, it'll mark the end of the current ice age.
20:35Earth's temperature is affected by something called the Milankovitch cycles.
20:40Basically, the amount of heat we receive from the sun changes over years, decades, and millennia
20:47because of Earth's orbit, tilt, and axis angle.
20:51There are three different patterns to these cycles.
20:55The first is called eccentricity, which is all about the shape of our orbit.
21:00The second is obliquity, which has to do with the tilt of the Earth.
21:05And the third is precession, which is like a wobble as Earth spins.
21:11Depending on where we are in these cycles, we might experience colder or warmer temperatures.
21:16But other things, like the position of continents and the atmosphere, also play a role in our planet's fate.
21:25For example, our planet's orbit is not quite circular.
21:29It's actually a bit elongated, shaped almost like an egg.
21:33That means we're sometimes a little closer or farther from the sun, depending on the time of year.
21:39We call the point farthest away from the sun the apogee, and the closest point is the perigee.
21:45When we're at the apogee, we're moving away from the sun, but gravity eventually pulls us back toward it.
21:52This means our orbit changes a little each time, gradually shifting our position relative to the sun.
21:59Don't worry, even though the orbit changes over thousands of years, it doesn't have a big impact on our day
22:05-to-day lives.
22:08Changes in Earth's orbit can affect how much sunlight we get during the summer.
22:12This means that ice sheets in the northern hemisphere will melt less, and over time, they actually start to grow.
22:19As they grow, they reflect even more sunlight, which makes the climate even cooler and spreads the ice even farther.
22:27This process can last for a really long time, like 10,000 to 20,000 years, and eventually, it brings
22:35the planet into its next freezing season.
22:40As for the next ice age, scientists believe it might be postponed indefinitely.
22:46They've found that our human interaction with the environment, like the use of fuels, could delay the next ice age
22:53by up to 100,000 years.
22:56Earth's past ice ages were linked to the amount of solar radiation and carbon dioxide concentration in the atmosphere.
23:03And this research can even help us predict future cycles.
23:08It's amazing to think that our actions now could affect Earth's future for thousands of years to come.
23:15And while it's not really important when the next ice age begins, it's pretty cool to know that humans have
23:21the power to shape the future on a geological timescale.
23:25Ice ages have had a huge impact on our planet and human civilization.
23:30So it's fascinating to think how our actions now might change things, maybe even for the better.
23:38What did life look like on our planet during the last ice age, though?
23:41Well, North America, for instance, was home to some huge creatures.
23:46Mammoths, saber-toothed cats, giant ground sloths, and mastodons were just a few of them.
23:54And get this, even Europe had an 11-foot-tall flightless bird that weighed almost as much as a polar
24:01bear.
24:03Meanwhile, down under in Australia, there was a giant lizard that lived in all sorts of habitats during the same
24:09time period.
24:11Even though some animals from the Pleistocene era aren't around anymore, you might recognize many of those that are still
24:18around today.
24:19In Alaska, for example, you can still find brown bears, caribou, and wolves.
24:27People just like us actually lived through the ice age, too.
24:30Our species, Homo sapiens, has been around for about 300,000 years.
24:36And we've spread all around the world since then.
24:39Some of our ancestors stayed in Africa during the ice age and didn't feel the full effects of the cold.
24:45And others ventured out into other parts of the world, even into the chilly glacial environments of Europe.
24:53Our early relatives, like the Neanderthals in Europe, and the mysterious Denisovians in Asia, were also around during this time.
25:02Although they seem to have gone extinct before the end of the ice age, it's pretty amazing to think about
25:08all those different hominids that roamed Earth during that period.
25:14What's also fascinating is how our species managed to survive the ice age, while some of our cousins didn't.
25:22Some experts believe that our adaptability, social and communication skills, and the use of tools played a huge role in
25:30it.
25:30And guess what? Humans didn't just hunker down during that time.
25:34We actually moved into new areas.
25:38Fossilized footprints found at White Sands National Park in New Mexico prove that humans have been in North America since
25:45at least 23,000 years ago.
25:47That's close to the peak of the last ice age.
25:51While a full-blown ice age might still be far away, there is a possibility of a mini-ice age
25:58coming our way.
26:00Some scientists believe that in about 10 years, we might experience a significant drop in solar activity, leading to colder
26:08temperatures in the Northern Hemisphere.
26:11This could result in conditions similar to the Little Ice Age in the late 17th century, when the Thames River
26:18in the UK froze over.
26:20While scientists aren't quite sure what caused that cooling, it's fascinating to think about the potential changes.
26:28We've done it before, so we know that humans will most likely survive the next real ice age, even if
26:35we don't manage to figure out a way to stop the next freezing era.
26:38But it would come at a high cost.
26:41All the ice that would cover most of the Northern Hemisphere would have to come from oceans, which would cause
26:47the sea level to drop.
26:49This could mean more land for some countries, but it would also create other problems.
26:56Sea levels going down might seem like a great thing at first, but actually, it could lead to some challenges.
27:03Having been covered with salt water for thousands of years, the new land might not be very fertile.
27:09This means it wouldn't be great for growing crops, and we'd have to find other ways to feed ourselves.
27:16Back when humans first started out, there weren't many of us.
27:20And there was plenty of food.
27:22Now, with over 7 billion people on the planet, it's a different story.
27:27We'll need to be resourceful to make sure everyone has enough food to eat.
27:31We'll need to make sure everyone has enough food to eat.
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