And even then, you only have a mini-copy that needs years to become remotely useful.

And even then , you only have a mini - copy that needs years to become remotely useful .


A bacterium consists of one cell.


It can make a fully-grown copy in about half an hour.

It can make a fully - grown copy in about half an hour .


A virus can turn into hundreds within hours, and billions within days.

A virus can turn into hundreds within hours , and billions within days .


Your enemies multiply orders of magnitude faster than you.

Your enemies multiply orders of magnitude faster than you .


Even worse, for a bacterium or virus, your body is a hostile ecosystem applying selective pressure.

Even worse , for a bacterium or virus , your body is a hostile ecosystem applying selective pressure .


Because they go through so many generations so quickly, eventually, by pure chance,

Because they go through so many generations so quickly , eventually , by pure chance ,


there will be an individual that mutates and adapts in just the right way to resist your defenses and then multiply quickly again.

there will be an individual that mutates and adapts in just the right way to resist your defenses and then multiply quickly again .


In other words, you're facing a sheer endless variety of different enemies, and you're too slow to keep up with their evolution.

In other words , you 're facing a sheer endless variety of different enemies , and you 're too slow to keep up with their evolution .


This is bad.


Luckily, your immune system is just about the most amazing thing ever.

Luckily , your immune system is just about the most amazing thing ever .


Since it's so complicated, we have to simplify and focus on one thing at a time.

Since it 's so complicated , we have to simplify and focus on one thing at a time .


If you want the full story, wait for the announcement at the end of the video.

If you want the full story , wait for the announcement at the end of the video .


Okay, so why are we not all killed by some new bacteria or virus?

Okay , so why are we not all killed by some new bacteria or virus ?


In a nutshell, you actually have two immune systems, the innate and the adaptive immune system.

In a nutshell , you actually have two immune systems , the innate and the adaptive immune system .


The innate immune system was ready when you were born.

The innate immune system was ready when you were born .


It mostly consists of general-purpose soldiers.

It mostly consists of general - purpose soldiers .


We introduced them in the last immune video.

We introduced them in the last immune video .


The adaptive immune system carries two types of cells, T-cells and B-cells, that are your super weapons and are incredibly effective and deadly for your enemies.

The adaptive immune system carries two types of cells , T - cells and B - cells , that are your super weapons and are incredibly effective and deadly for your enemies .


These cells are complicated to produce and take a lot of time to deploy, but once they're ready, they pack a real punch.

These cells are complicated to produce and take a lot of time to deploy , but once they 're ready , they pack a real punch .


What makes your adaptive immune system so powerful is that it has the largest library in the universe.

What makes your adaptive immune system so powerful is that it has the largest library in the universe .


It has an answer to everything.


You have at least one of these super weapon cells inside you to fight the Black Death, the coronavirus,

You have at least one of these super weapon cells inside you to fight the Black Death , the coronavirus ,


This makes it possible for you to counter the ability of bacteria and viruses to change so rapidly.

This makes it possible for you to counter the ability of bacteria and viruses to change so rapidly .


How is this possible?


To understand what's going on here, we need to take one step back.

To understand what 's going on here , we need to take one step back .


All organisms on Earth are made from the same basic parts, mostly proteins.

All organisms on Earth are made from the same basic parts , mostly proteins .


Proteins are the building blocks of life and can have billions of different shapes.

Proteins are the building blocks of life and can have billions of different shapes .


You can imagine them as 3D puzzle pieces.

You can imagine them as 3D puzzle pieces .


There are billions of different puzzle pieces your enemies can use to construct their bodies.

There are billions of different puzzle pieces your enemies can use to construct their bodies .


Why is this important?


Because proteins are, in a way, the language of the micro-world.

Because proteins are , in a way , the language of the micro - world .


Cells don't have eyes or ears, so to tell friend from foe, they have to touch them and recognize if their protein is part of a friend or part of an enemy.

Cells do n't have eyes or ears , so to tell friend from foe , they have to touch them and recognize if their protein is part of a friend or part of an enemy .


Recognizing means that cells have countless tiny devices called receptors that are able to connect with a specific protein puzzle piece.

Recognizing means that cells have countless tiny devices called receptors that are able to connect with a specific protein puzzle piece .


So your cells have tiny puzzle pieces on their outsides that are able to click together or recognize other protein puzzle pieces.

So your cells have tiny puzzle pieces on their outsides that are able to click together or recognize other protein puzzle pieces .


When a cell connects together with a protein and recognizes it as enemy, it knows that it has to attack.

When a cell connects together with a protein and recognizes it as enemy , it knows that it has to attack .


Only if your cells can make this distinction between friend or foe is your immune system able to fight an invader.

Only if your cells can make this distinction between friend or foe is your immune system able to fight an invader .


But since there are billions of possible protein puzzle pieces, this means there are billions of possible enemy puzzle pieces.

But since there are billions of possible protein puzzle pieces , this means there are billions of possible enemy puzzle pieces .


This is also one of the reasons we still have to deal with diseases like the flu each year.

This is also one of the reasons we still have to deal with diseases like the flu each year .


The influenza virus mutates very rapidly, and so the proteins that make up its hull constantly change a tiny bit.

The influenza virus mutates very rapidly , and so the proteins that make up its hull constantly change a tiny bit .


The soldiers of your innate immune system have a large number of the puzzle pieces for common bacteria and viruses memorized.

The soldiers of your innate immune system have a large number of the puzzle pieces for common bacteria and viruses memorized .


That's why they are your all-purpose weapons.

That 's why they are your all - purpose weapons .


They are ineffective against many billions of mutations and adaptations that your enemies can develop.

They are ineffective against many billions of mutations and adaptations that your enemies can develop .


So the reason you are still alive is that your adaptive immune system is able to recognize between 1 billion and 10 billion different enemy protein puzzle pieces,

So the reason you are still alive is that your adaptive immune system is able to recognize between 1 billion and 10 billion different enemy protein puzzle pieces ,


But how is this possible?


How could your immune system possibly have this much of a variety to be prepared for every possible protein puzzle piece?

How could your immune system possibly have this much of a variety to be prepared for every possible protein puzzle piece ?


Well, the cells of your adaptive immune system found a cheat code, mixing and matching their own genetic code to create this stunning variety of receptors.

Well , the cells of your adaptive immune system found a cheat code , mixing and matching their own genetic code to create this stunning variety of receptors .


The details are way too complicated for this video, but in a nutshell,

The details are way too complicated for this video , but in a nutshell ,


your adaptive immune cells have official permission to take a tiny part of their own genetic code and mix it in random ways to create billions of different receptors.

your adaptive immune cells have official permission to take a tiny part of their own genetic code and mix it in random ways to create billions of different receptors .


A good way to explain this is by asking you to imagine an army of cooks, with each of them wanting their own special recipe.

A good way to explain this is by asking you to imagine an army of cooks , with each of them wanting their own special recipe .


They have 100 different ingredients to choose from.

They have 100 different ingredients to choose from .


Each ingredient stands for one tiny piece of genetic code in this metaphor.

Each ingredient stands for one tiny piece of genetic code in this metaphor .


So each cook takes a few random ingredients and randomly mixes them together.

So each cook takes a few random ingredients and randomly mixes them together .


Even with slight variation and with only 100 ingredients, there are billions of possible recipes.

Even with slight variation and with only 100 ingredients , there are billions of possible recipes .


And likewise, with just a small selection of gene fragments, your cells create billions of receptors.

And likewise , with just a small selection of gene fragments , your cells create billions of receptors .


The details of this are so cool that they should get their own video, or their own chapter in a book.

The details of this are so cool that they should get their own video , or their own chapter in a book .


In any case, by mixing up gene fragments, you get up to 10 billion different combinations.

In any case , by mixing up gene fragments , you get up to 10 billion different combinations .


So in the end, you get billions of immune cells, and each of them has one specific and unique receptor,

So in the end , you get billions of immune cells , and each of them has one specific and unique receptor ,


In total, you end up with at least one cell for every enemy that could possibly exist.

In total , you end up with at least one cell for every enemy that could possibly exist .


But here we run into a pretty dangerous problem.

But here we run into a pretty dangerous problem .


wouldn't it also make some that can attack your own cells?

would n't it also make some that can attack your own cells ?


Yes, it happens all the time.


This is so fundamentally dangerous to your survival, that you have a whole organ that does nothing but work on preventing this.

This is so fundamentally dangerous to your survival , that you have a whole organ that does nothing but work on preventing this .


Your thymus is a chicken wing sized organ above your heart, and you've probably never heard of it.

Your thymus is a chicken wing sized organ above your heart , and you 've probably never heard of it .


Interestingly, your thymus is one of the reasons why your immune system weakens as you age,

Interestingly , your thymus is one of the reasons why your immune system weakens as you age ,


because it's in a constant state of decline once you reach puberty.

because it 's in a constant state of decline once you reach puberty .


But what does the thymus do?


In your murder university, your immune system is putting your adaptive immune cells through an intense and deadly curriculum.

In your murder university , your immune system is putting your adaptive immune cells through an intense and deadly curriculum .


Basically, it's showing them all sorts of protein puzzle pieces that are used by your own cells to see how they react.

Basically , it 's showing them all sorts of protein puzzle pieces that are used by your own cells to see how they react .


When a young cell recognizes a body puzzle piece and wants to attack it, the teacher's cells order them to kill themselves, and they are eaten up and recycled.

When a young cell recognizes a body puzzle piece and wants to attack it , the teacher 's cells order them to kill themselves , and they are eaten up and recycled .


The immune system is so particular about this process, that around 98% of your adaptive immune cells that enter murder university die there.

The immune system is so particular about this process , that around 98 % of your adaptive immune cells that enter murder university die there .


2% graduate and get to do their job of protecting you for real.

2 % graduate and get to do their job of protecting you for real .


If this process goes wrong and the cells escape that can recognize your own protein puzzle pieces,

If this process goes wrong and the cells escape that can recognize your own protein puzzle pieces ,


this can lead to autoimmune disease, where your immune system attacks your own body from the inside.

this can lead to autoimmune disease , where your immune system attacks your own body from the inside .


And this, again, is another story for another time.

And this , again , is another story for another time .


Okay, let's summarize.


Your immune system has two parts, one that defends you right after birth, and one that carries the largest library of superweapons in the universe, but needs to boot up first.

Your immune system has two parts , one that defends you right after birth , and one that carries the largest library of superweapons in the universe , but needs to boot up first .


To create billions of different superweapons, your adaptive immune cells recombine a part of their genetic code to create a breathtaking variety of attack weapons.

To create billions of different superweapons , your adaptive immune cells recombine a part of their genetic code to create a breathtaking variety of attack weapons .


Then they enter a murder university that only 2% survive to make sure they don't attack you.

Then they enter a murder university that only 2 % survive to make sure they do n't attack you .


And then you end up with billions of different cells that in total are able to protect you against every possible enemy in the universe.

And then you end up with billions of different cells that in total are able to protect you against every possible enemy in the universe .


Now, wait a second.


If this is all true, why do we get sick at all?

If this is all true , why do we get sick at all ?


Why was a new disease like COVID-19 able to kill millions of people?

Why was a new disease like COVID-19 able to kill millions of people ?


And how do vaccines boost the mechanisms we explained in this video to supercharge your immune system and defend you from the worst diseases humanity has ever encountered from smallpox to COVID-19?

And how do vaccines boost the mechanisms we explained in this video to supercharge your immune system and defend you from the worst diseases humanity has ever encountered from smallpox to COVID-19 ?


Well, everything we've just learned about is a tiny, tiny window into the amazing struggle for life and death that plays out every day inside your body,

Well , everything we 've just learned about is a tiny , tiny window into the amazing struggle for life and death that plays out every day inside your body ,


and there are so many amazing details and questions here.

and there are so many amazing details and questions here .


How does your body actually find the right cell in time to protect you?

How does your body actually find the right cell in time to protect you ?


How do your enemies fight back and overcome your immune system anyway?

How do your enemies fight back and overcome your immune system anyway ?


Well, today finally marks the release of Immune! A Journey Into The Mysterious System That Keeps You Alive,

Well , today finally marks the release of Immune ! A Journey Into The Mysterious System That Keeps You Alive ,


First, we had to push the release back because of cargo trouble, and then because so many of you pre-ordered that we didn't have enough copies for the original launch day.

First , we had to push the release back because of cargo trouble , and then because so many of you pre - ordered that we did n't have enough copies for the original launch day .


Thank you so, so much for that!


Immune tells the epic story of your immune system and will forever change how you think about your own body, how you experience being sick and healthy.

Immune tells the epic story of your immune system and will forever change how you think about your own body , how you experience being sick and healthy .


The book is written to be as fun and easy to grasp as Kurzgesagt videos, but is able to dive way deeper into its subject.

The book is written to be as fun and easy to grasp as Kurzgesagt videos , but is able to dive way deeper into its subject .


So go on a journey through the hidden microverse within yourself.

So go on a journey through the hidden microverse within yourself .


Witness deadly wars between billions of invaders and cells, learn how your immune system actually works and protects you from cuts, cancer and COVID.

Witness deadly wars between billions of invaders and cells , learn how your immune system actually works and protects you from cuts , cancer and COVID .


Never before have we so urgently needed to learn about how immunity works.

Never before have we so urgently needed to learn about how immunity works .


Immune is fun and great to look at, and it even smells good.

Immune is fun and great to look at , and it even smells good .


Follow the link in the description to order it today.

Follow the link in the description to order it today .


This is the end of a decade-long personal journey working on this, so thank you all so, so much for your support.

This is the end of a decade - long personal journey working on this , so thank you all so , so much for your support .


And thank you for watching. And reading.

And thank you for watching . And reading .


Look around you.


But where is all of that?


While this may feel like a daft question, it turns out that the concept of an absolute position is something humans made up.

While this may feel like a daft question , it turns out that the concept of an absolute position is something humans made up .


In a nutshell, the universe is a big bag of space that has things in it.

In a nutshell , the universe is a big bag of space that has things in it .


If someone removed all these things, the stars and planets and black holes and dust, there would just be empty space left.

If someone removed all these things , the stars and planets and black holes and dust , there would just be empty space left .


In empty space, the concept of having a position loses all meaning.

In empty space , the concept of having a position loses all meaning .


Empty space is uniform, the same everywhere.

Empty space is uniform , the same everywhere .


The space we occupy is not like a stage under our feet.

The space we occupy is not like a stage under our feet .


We can't mark specific points or staple something to space-time as an anchor.

We ca n't mark specific points or staple something to space - time as an anchor .


Without things, there is no position.


We are really ever only at a position in relation to something else.

We are really ever only at a position in relation to something else .


Okay, let's fill the universe up with things again and try to find out where you are right now, relative to everything else.

Okay , let 's fill the universe up with things again and try to find out where you are right now , relative to everything else .


Let's start this video at a familiar place and then get increasingly weird.

Let 's start this video at a familiar place and then get increasingly weird .


From your perspective, the world is seemingly flat and you can move in three dimensions.

From your perspective , the world is seemingly flat and you can move in three dimensions .


It's what physicists call a frame of reference.

It 's what physicists call a frame of reference .


Your frame of reference is correct, for you.

Your frame of reference is correct , for you .


Around 5 kilometers from you, where the horizon begins, the ground noticeably curves away from you.

Around 5 kilometers from you , where the horizon begins , the ground noticeably curves away from you .


If you could see through the ground, you'd see people from below or sideways.

If you could see through the ground , you 'd see people from below or sideways .


But they don't fall down off the planet because gravity doesn't actually pull them down.

But they do n't fall down off the planet because gravity does n't actually pull them down .


Down is an illusion of your reference frame.

Down is an illusion of your reference frame .


To Earth's reference frame, gravity just pulls in.

To Earth 's reference frame , gravity just pulls in .


But for humans, there is an up and down, because within our frame of reference, that just makes sense.

But for humans , there is an up and down , because within our frame of reference , that just makes sense .


And we made our maps accordingly.


But an observer looking at the solar system might disagree.

But an observer looking at the solar system might disagree .


Our maps make sense to us because we're used to them, not because they are correct.

Our maps make sense to us because we 're used to them , not because they are correct .


Okay, so this is step one.


But this sphere is always moving, never staying in one position.

But this sphere is always moving , never staying in one position .


Earth is orbiting a star, the Sun at the center of the solar system.

Earth is orbiting a star , the Sun at the center of the solar system .


While we usually imagine this as pretty orderly, someone looking at us from the outside would see something pretty messy.

While we usually imagine this as pretty orderly , someone looking at us from the outside would see something pretty messy .


To see this more clearly, we'll exaggerate all these movements.

To see this more clearly , we 'll exaggerate all these movements .


This is not to scale.


First of all, our orbit really is an ellipse.

First of all , our orbit really is an ellipse .


So we spend half the year sinking a little bit closer to the Sun, speeding up.

So we spend half the year sinking a little bit closer to the Sun , speeding up .


And the ellipse itself changes its shape every 100,000 years too.

And the ellipse itself changes its shape every 100,000 years too .


And in another cycle of 112,000 years, the ellipse itself is drifting.

And in another cycle of 112,000 years , the ellipse itself is drifting .


In the end, we get an orbital path that looks like a wobbly circle with wavy edges.

In the end , we get an orbital path that looks like a wobbly circle with wavy edges .


And it gets worse as the Moon now starts to mess things up too.

And it gets worse as the Moon now starts to mess things up too .


As the Moon is a pretty massive thing, it pulls on Earth.

As the Moon is a pretty massive thing , it pulls on Earth .


Both objects orbit their common center of gravity that lies around 4,700 kilometers off to the side of Earth's core.

Both objects orbit their common center of gravity that lies around 4,700 kilometers off to the side of Earth 's core .


In practice, this means that as the Moon orbits Earth, it's jerking Earth around a bit, enough to make it jiggle.

In practice , this means that as the Moon orbits Earth , it 's jerking Earth around a bit , enough to make it jiggle .


Okay, so you're standing on the surface of a rotating planet that is jiggling around the Sun in an elliptical orbit that changes a bit every year.

Okay , so you 're standing on the surface of a rotating planet that is jiggling around the Sun in an elliptical orbit that changes a bit every year .


But who's to say the Earth is right?


From the perspective of the Sun, the plane of the Solar System is arbitrary.

From the perspective of the Sun , the plane of the Solar System is arbitrary .


It's defined as the plane the Earth orbits in because that is convenient for us.

It 's defined as the plane the Earth orbits in because that is convenient for us .


In reality, the other planets are just a little bit inclined with respect to our plane.

In reality , the other planets are just a little bit inclined with respect to our plane .


From their point of view, we're the ones with a slightly bent orbit.

From their point of view , we 're the ones with a slightly bent orbit .


But this isn't it.


The Solar System as a whole is orbiting the center of the Milky Way galaxy.

The Solar System as a whole is orbiting the center of the Milky Way galaxy .


If we look at the Milky Way, we can clearly make out a galactic plane in which the Solar System orbits the center every 230 million years.

If we look at the Milky Way , we can clearly make out a galactic plane in which the Solar System orbits the center every 230 million years .


But of course, it's not that simple.


First of all, the plane of the Solar System is not aligned with the plane of the galaxy.

First of all , the plane of the Solar System is not aligned with the plane of the galaxy .


Just like the planets in the Solar System orbit the Sun on their own planes, so do all the stars orbiting the galactic center.

Just like the planets in the Solar System orbit the Sun on their own planes , so do all the stars orbiting the galactic center .


The Solar System as a whole is tilted about 60 degrees towards the galactic plane, speeding through space at almost a million kilometers per hour.

The Solar System as a whole is tilted about 60 degrees towards the galactic plane , speeding through space at almost a million kilometers per hour .


Someone in the center of the galaxy would see the orbits of the planets moving through space in a helix shape,

Someone in the center of the galaxy would see the orbits of the planets moving through space in a helix shape ,


This orientation in space means that sometimes the planets are sort of in front of the Sun as it orbits around the galactic core.

This orientation in space means that sometimes the planets are sort of in front of the Sun as it orbits around the galactic core .


Let's just look at this for a moment.


There is a strange and eerie beauty about how our planets and the Sun move through space.

There is a strange and eerie beauty about how our planets and the Sun move through space .


Do you feel a bit dizzy?


It gets worse.


This is still not the whole story because the mass of the galactic disk is constantly pulling on the Solar System too.

This is still not the whole story because the mass of the galactic disk is constantly pulling on the Solar System too .


Like a drunk dolphin, we're diving down and shooting up hundreds of light-years through the galactic plane ten times every orbit along arcs thousands of light-years long.

Like a drunk dolphin , we 're diving down and shooting up hundreds of light - years through the galactic plane ten times every orbit along arcs thousands of light - years long .


We haven't mapped this motion out completely as it takes the Solar System tens of millions of years to go up and back once, and well, humanity is not that old.

We have n't mapped this motion out completely as it takes the Solar System tens of millions of years to go up and back once , and well , humanity is not that old .


Let's look at your relative position again.

Let 's look at your relative position again .


At this point, the frame of reference becomes a bit arbitrary and pointless because of the nature of the universe at this scale.

At this point , the frame of reference becomes a bit arbitrary and pointless because of the nature of the universe at this scale .


The Milky Way is part of a galaxy group that appears to be part of greater structures like the Laniakea Supercluster,

The Milky Way is part of a galaxy group that appears to be part of greater structures like the Laniakea Supercluster ,


Someone looking right at us from that far away will only see the end of greatness.

Someone looking right at us from that far away will only see the end of greatness .


All stuff appears homogeneous, the same everywhere.

All stuff appears homogeneous , the same everywhere .


Just like with empty space, when everything looks the same, who's to say anyone's view is better than anyone else's?

Just like with empty space , when everything looks the same , who 's to say anyone 's view is better than anyone else 's ?


We've reached the end of our little exercise in cosmic humidity.

We 've reached the end of our little exercise in cosmic humidity .


Let's make the journey backwards again, from the indescribably large to the really large to our galactic home to our galaxy,

Let 's make the journey backwards again , from the indescribably large to the really large to our galactic home to our galaxy ,


If this is all a bit much, don't feel bad.

If this is all a bit much , do n't feel bad .


The scale of the universe is brain-crushing, and trying to keep track of how everything is oriented or decide where the best up and down is, is hard.

The scale of the universe is brain - crushing , and trying to keep track of how everything is oriented or decide where the best up and down is , is hard .


But it doesn't really matter, because it doesn't change where you are.

But it does n't really matter , because it does n't change where you are .


You're already in the best spot you possibly could be, right here, right now.

You 're already in the best spot you possibly could be , right here , right now .


For all you care, nothing can stop you from being right at the center of your own little universe.

For all you care , nothing can stop you from being right at the center of your own little universe .


Perspective really is everything.


That's true for the universe we all inhabit, but even more so within your personal universe.

That 's true for the universe we all inhabit , but even more so within your personal universe .


The way your life will unfold also depends on what you consider possible.

The way your life will unfold also depends on what you consider possible .


Take us at Kurzgesagt.


Our passion is to spark curiosity for science and make videos for free.

Our passion is to spark curiosity for science and make videos for free .


But this is not a great business model, so we began to create our own lines of science posters, calendars,

But this is not a great business model , so we began to create our own lines of science posters , calendars ,


And we're doing this with Shopify, who were also so kind as to sponsor this video, which delighted us because we've been using their platform for years now.

And we 're doing this with Shopify , who were also so kind as to sponsor this video , which delighted us because we 've been using their platform for years now .


Shopify is an e-commerce platform that allows you to start and grow your business.

Shopify is an e - commerce platform that allows you to start and grow your business .


And by starting a business, we really do mean from scratch.

And by starting a business , we really do mean from scratch .


But not just that, if you want to scale your one-man show to a sizable team, then Shopify has the tools to support you on your journey.

But not just that , if you want to scale your one - man show to a sizable team , then Shopify has the tools to support you on your journey .


Now, you just have to get started.


Go to shopify.com/kurzgesagt to get a free 14-day trial.

Go to shopify.com/kurzgesagt to get a free 14 - day trial .


If you think that this idea doesn't apply to you and your ideas are too small, we want to encourage you to think again.

If you think that this idea does n't apply to you and your ideas are too small , we want to encourage you to think again .


The first video on this channel was a university project, and Kurzgesagt itself was a creative outlet.

The first video on this channel was a university project , and Kurzgesagt itself was a creative outlet .


Eventually, we grew into a business and the team that is making videos for you today.

Eventually , we grew into a business and the team that is making videos for you today .


This is exactly the sort of thing that Shopify is determined to support, and you can build your own thing with it.

This is exactly the sort of thing that Shopify is determined to support , and you can build your own thing with it .


After all, whether your idea is still just a dream or might turn into a plan today is also just a matter of perspective.

After all , whether your idea is still just a dream or might turn into a plan today is also just a matter of perspective .


Millions of businesses in over 175 countries are currently using Shopify to sell their products, and we are one of them.

Millions of businesses in over 175 countries are currently using Shopify to sell their products , and we are one of them .


Somewhere in your body, your immune system just quietly killed one of your own cells, stopping it from becoming cancer and saving your life.

Somewhere in your body , your immune system just quietly killed one of your own cells , stopping it from becoming cancer and saving your life .


It does that all the time.


The vast majority of cancer cells you develop will be killed without you ever noticing, which is an incredibly hard job because of what cancer cells are.

The vast majority of cancer cells you develop will be killed without you ever noticing , which is an incredibly hard job because of what cancer cells are .


What is cancer and how does your body kill it all the time?

What is cancer and how does your body kill it all the time ?


Cancer is when corrupted cells multiply uncontrollably.

Cancer is when corrupted cells multiply uncontrollably .


It can emerge from basically every type of cell in your body, so there's not just a single type of cancer, but hundreds.

It can emerge from basically every type of cell in your body , so there 's not just a single type of cancer , but hundreds .


Some grow slowly, others are aggressive, some can be treated effectively, others are deadly.

Some grow slowly , others are aggressive , some can be treated effectively , others are deadly .


In a sense, a cell that becomes cancer turns into something ancient and something new.

In a sense , a cell that becomes cancer turns into something ancient and something new .


Over billions of years, evolution has molded cells to survive and thrive in a hostile environment, fighting for space and resources.

Over billions of years , evolution has molded cells to survive and thrive in a hostile environment , fighting for space and resources .


But cooperation requires sacrifices.


For a multicellular being to stay healthy, the well-being of the collective has to matter more than the survival of the individual cell.

For a multicellular being to stay healthy , the well - being of the collective has to matter more than the survival of the individual cell .


Cancer cells stop being part of the collective and become individuals again.

Cancer cells stop being part of the collective and become individuals again .


Your body can handle a few rogue cells, but some cancer cells divide again and again,

Your body can handle a few rogue cells , but some cancer cells divide again and again ,


Despite the harm they cause, cancer cells are not evil.

Despite the harm they cause , cancer cells are not evil .


They don't want to hurt you, they don't want anything.

They do n't want to hurt you , they do n't want anything .


Cells are protein robots that just follow their programming, which unfortunately has been corrupted.

Cells are protein robots that just follow their programming , which unfortunately has been corrupted .


In a nutshell, your cells have a nucleus filled with DNA.

In a nutshell , your cells have a nucleus filled with DNA .


It consists of genes, instructions for how to build proteins, and when to make each one.

It consists of genes , instructions for how to build proteins , and when to make each one .


These building instructions are copied and transferred to ribosomes, where they're used to make proteins.

These building instructions are copied and transferred to ribosomes , where they 're used to make proteins .


What kind of proteins your cells make determine what they can do.

What kind of proteins your cells make determine what they can do .


The important thing here is that a corrupt gene means you get a corrupt protein, which will get important later.

The important thing here is that a corrupt gene means you get a corrupt protein , which will get important later .


Your DNA gets a tiny bit corrupted.


It mutates tens of thousands of times each day.

It mutates tens of thousands of times each day .


Almost all of these mutations are fixed very quickly, or are not problematic.

Almost all of these mutations are fixed very quickly , or are not problematic .


Still, over time, as your cells make copies of themselves, damage is accumulating.

Still , over time , as your cells make copies of themselves , damage is accumulating .


Imagine having to make copies from copies from copies for decades.

Imagine having to make copies from copies from copies for decades .


Maybe one day a hair got on the scanner, or a corner got frayed.

Maybe one day a hair got on the scanner , or a corner got frayed .


Each new mistake becomes part of the new copies, and all the copies that follow.

Each new mistake becomes part of the new copies , and all the copies that follow .


You can increase DNA damage by doing things like smoking, drinking alcohol, by being obese, breathing in asbestos, by not using sunscreen, or contracting a virus like HPV.

You can increase DNA damage by doing things like smoking , drinking alcohol , by being obese , breathing in asbestos , by not using sunscreen , or contracting a virus like HPV .


But the simplest way to damage DNA and get cancer is to be alive long enough.

But the simplest way to damage DNA and get cancer is to be alive long enough .


For many cancer cases, there is no cause other than bad luck.

For many cancer cases , there is no cause other than bad luck .


We are simplifying, but roughly there are three categories of genes that need to be corrupted so cancer can arise.

We are simplifying , but roughly there are three categories of genes that need to be corrupted so cancer can arise .


The first key mutation is in the appropriately named tumor suppressor genes, or TSGs.

The first key mutation is in the appropriately named tumor suppressor genes , or TSGs .


These genes are a bunch of things.


For one, they produce control mechanisms that continuously scan your DNA for mistakes and copying errors, and fix them right away.

For one , they produce control mechanisms that continuously scan your DNA for mistakes and copying errors , and fix them right away .


And then they keep normal cells from multiplying recklessly.

And then they keep normal cells from multiplying recklessly .


If TSGs become damaged, your cells basically forget how to repair themselves, and can reproduce unchecked.

If TSGs become damaged , your cells basically forget how to repair themselves , and can reproduce unchecked .


The second crucial mutation can happen in your oncogenes.

The second crucial mutation can happen in your oncogenes .


When oncogenes are turned on, the cell is told to multiply rapidly.

When oncogenes are turned on , the cell is told to multiply rapidly .


They were super active when you were inside your mother's womb.

They were super active when you were inside your mother 's womb .


To turn a single original cell into trillions in months, it needs to divide and grow rapidly.

To turn a single original cell into trillions in months , it needs to divide and grow rapidly .


These rapid growth genes are turned off when there's enough of you.

These rapid growth genes are turned off when there 's enough of you .


When your oncogenes get corrupted, they basically turn on again.

When your oncogenes get corrupted , they basically turn on again .


The third crucial mutation is in your cell's suicide switch.

The third crucial mutation is in your cell 's suicide switch .


Most cells are constantly recycled and refreshed.

Most cells are constantly recycled and refreshed .


When cells amass too much damage, they usually notice, and special genes trigger a controlled suicide called apoptosis.

When cells amass too much damage , they usually notice , and special genes trigger a controlled suicide called apoptosis .


If the genes that control this process get damaged, cells are free to live on, despite being dangerously corrupted.

If the genes that control this process get damaged , cells are free to live on , despite being dangerously corrupted .


and begins to grow rapidly without restraint, it turns into a young cancer cell.

and begins to grow rapidly without restraint , it turns into a young cancer cell .


These cells have to be killed as quickly as possible.

These cells have to be killed as quickly as possible .


While they are bad at this stage, they are still pretty weak and easy to kill.

While they are bad at this stage , they are still pretty weak and easy to kill .


But if they continue to mutate and increase in number, they can learn to avoid your defenses and become a real threat.

But if they continue to mutate and increase in number , they can learn to avoid your defenses and become a real threat .


At any moment of your life, your immune system is hunting these cells.

At any moment of your life , your immune system is hunting these cells .


But how do you identify and kill corrupted cells that seem indistinguishable from healthy ones?

But how do you identify and kill corrupted cells that seem indistinguishable from healthy ones ?


Well, here we come back to the proteins your cells produce and the story they tell.

Well , here we come back to the proteins your cells produce and the story they tell .


So, if for example your oncogenes switch back on, they make oncogene proteins.

So , if for example your oncogenes switch back on , they make oncogene proteins .


Your immune system knows that they should not be present if you're an adult.

Your immune system knows that they should not be present if you 're an adult .


So to know which cells are corrupt and which are healthy, your immune system needs to know what proteins they're making inside.

So to know which cells are corrupt and which are healthy , your immune system needs to know what proteins they 're making inside .


To solve this, evolution came up with MHC class 1 molecules, a sort of display window that makes cells transparent.

To solve this , evolution came up with MHC class 1 molecules , a sort of display window that makes cells transparent .


Cells constantly take little samples of the proteins they make and put them into thousands of these MHC molecules to showcase what they're doing.

Cells constantly take little samples of the proteins they make and put them into thousands of these MHC molecules to showcase what they 're doing .


The selection is constantly refreshed, always giving an up-to-date picture.

The selection is constantly refreshed , always giving an up - to - date picture .


There's a whole library of proteins that are highly dangerous and should not be made by healthy cells, and your immune system has them all on file.

There 's a whole library of proteins that are highly dangerous and should not be made by healthy cells , and your immune system has them all on file .


It has billions of specialized cells called T-cells made to recognize specific proteins.

It has billions of specialized cells called T - cells made to recognize specific proteins .


If a T-cell sees a forbidden protein in an MHC display window, it knows that the cell is corrupted and kills it immediately.

If a T - cell sees a forbidden protein in an MHC display window , it knows that the cell is corrupted and kills it immediately .


But there's a flaw in this system.


All it needs to do is to stop making MHC class 1 molecules and boom, it's invisible.

All it needs to do is to stop making MHC class 1 molecules and boom , it 's invisible .


Without display windows, the immune system is blind and can't identify cancer anymore.

Without display windows , the immune system is blind and ca n't identify cancer anymore .


Fortunately, evolution found an ingenious solution.

Fortunately , evolution found an ingenious solution .


At this very second, hundreds of millions of natural killer cells are patrolling your body looking for cells that have already turned into cancer or are corrupted by a virus.

At this very second , hundreds of millions of natural killer cells are patrolling your body looking for cells that have already turned into cancer or are corrupted by a virus .


Natural killer cells go from cell to cell to check for one thing.

Natural killer cells go from cell to cell to check for one thing .


Does a cell have MHC class 1 molecules?

Does a cell have MHC class 1 molecules ?


Does it have a display window and is it doing its duty of showing off what's going on inside itself?

Does it have a display window and is it doing its duty of showing off what 's going on inside itself ?


This is so amazing because it covers all of your bases.

This is so amazing because it covers all of your bases .


While T-cells look for the presence of the unexpected, something that should not be here, natural killer cells look for the absence of the expected, the absence of something that should be here.

While T - cells look for the presence of the unexpected , something that should not be here , natural killer cells look for the absence of the expected , the absence of something that should be here .


The logic is, if a cell does not have display windows, it wants to hide something.

The logic is , if a cell does not have display windows , it wants to hide something .


And a cell that hides something must be killed.

And a cell that hides something must be killed .


What makes the natural killer cell even more metal is that it's always in murder mode.

What makes the natural killer cell even more metal is that it 's always in murder mode .


It patrols your body checking cell after cell with the intention of killing it.

It patrols your body checking cell after cell with the intention of killing it .


Your healthy cells have to convince it that they should not die today.

Your healthy cells have to convince it that they should not die today .


And a way to do that is to have MHC class 1 molecules.

And a way to do that is to have MHC class 1 molecules .


So, in summary, almost all young cancer cells you will ever develop in your life will be killed by your immune system.

So , in summary , almost all young cancer cells you will ever develop in your life will be killed by your immune system .


Okay, but if your body is this prepared, why do we still get cancer?

Okay , but if your body is this prepared , why do we still get cancer ?


Well, sometimes cancer cells mutate more and get much better at fighting back.

Well , sometimes cancer cells mutate more and get much better at fighting back .


Cancer is a story of an arms race.


Right now, a number of therapies are beginning to show amazing promise, from cancer-fighting vaccines to engineered T-cells and even natural killer cells.

Right now , a number of therapies are beginning to show amazing promise , from cancer - fighting vaccines to engineered T - cells and even natural killer cells .


We'll look at these therapies in future videos.

We 'll look at these therapies in future videos .


So, the war is not won yet, but we are on to cancer and eventually it will be eliminated once and for all.

So , the war is not won yet , but we are on to cancer and eventually it will be eliminated once and for all .


This video was made possible in part by direct viewer support and in part through a grant by Gates Ventures.

This video was made possible in part by direct viewer support and in part through a grant by Gates Ventures .


Please check out our source document for more background and in-depth information.

Please check out our source document for more background and in - depth information .


From hostile deserts to lonely islands and the highest mountains, wherever there is space to expand into, humans do so.

From hostile deserts to lonely islands and the highest mountains , wherever there is space to expand into , humans do so .


So it's hardly surprising that we're already making preparations to set foot on Mars and to create the first permanent colony outside of Earth,

So it 's hardly surprising that we 're already making preparations to set foot on Mars and to create the first permanent colony outside of Earth ,


maybe even terraform another planet and turn it into a second blue home.

maybe even terraform another planet and turn it into a second blue home .


Before we can get to the nice future stuff, we first have to complete the second phase of colonization, creating a semi-permanent outpost to prepare the ground for a larger human presence.

Before we can get to the nice future stuff , we first have to complete the second phase of colonization , creating a semi - permanent outpost to prepare the ground for a larger human presence .


But doing so will be gruesome.


Even for an expansionist species like us, Mars is extreme.

Even for an expansionist species like us , Mars is extreme .


At first glance, Mars seems familiar.


Unfortunately, Mars is actually a cold, radioactive desert where the ground is poisonous and breathing is impossible.

Unfortunately , Mars is actually a cold , radioactive desert where the ground is poisonous and breathing is impossible .


Mars is awful.


You almost certainly don't want to go there.

You almost certainly do n't want to go there .


The pioneers doing the hard work on Mars will have an intensely stressful life filled with incredibly challenging problems, never encountered before.

The pioneers doing the hard work on Mars will have an intensely stressful life filled with incredibly challenging problems , never encountered before .


But there are plenty of people willing to do that work and we have the technology to enable them to do it.

But there are plenty of people willing to do that work and we have the technology to enable them to do it .


For this video, we will assume there have been prior missions to Mars to scout out a good place for an outpost, store resources and equipment and that there's already a moon base that serves as a hub for Mars missions.

For this video , we will assume there have been prior missions to Mars to scout out a good place for an outpost , store resources and equipment and that there 's already a moon base that serves as a hub for Mars missions .


The first major challenge for our outpost is the fact that Mars is very energy poor.

The first major challenge for our outpost is the fact that Mars is very energy poor .


Because of its distance from the Sun, solar power is only 40% as effective as on Earth.

Because of its distance from the Sun , solar power is only 40 % as effective as on Earth .


But even this weakened sunlight is often obscured for days by enormous dust storms.

But even this weakened sunlight is often obscured for days by enormous dust storms .


Solar power alone will probably not be enough.

Solar power alone will probably not be enough .


Alternatives such as wind power and geothermal energy are also unfeasible as there's hardly any atmosphere and Mars's interior is much too cold.

Alternatives such as wind power and geothermal energy are also unfeasible as there 's hardly any atmosphere and Mars 's interior is much too cold .


Initially, nuclear technology might be the only option.

Initially , nuclear technology might be the only option .


Since Mars doesn't have easily accessible radioactive elements, the nuclear fuel needs to come from Earth along with the reactor.

Since Mars does n't have easily accessible radioactive elements , the nuclear fuel needs to come from Earth along with the reactor .


If we do set it up, it could power our small outpost for the first few years.

If we do set it up , it could power our small outpost for the first few years .


Unfortunately, all that energy won't be very useful if we can't breathe.

Unfortunately , all that energy wo n't be very useful if we ca n't breathe .


Mars's atmosphere is only 1% as dense as Earth's and mostly made up of CO2.

Mars 's atmosphere is only 1 % as dense as Earth 's and mostly made up of CO2 .


So our habitats need to be pressurized and filled with an artificial atmosphere made of nitrogen and oxygen, which comes with more problems.

So our habitats need to be pressurized and filled with an artificial atmosphere made of nitrogen and oxygen , which comes with more problems .


Corners and flat walls are weak points, so the habitats will have rounded and smooth shapes to handle the stress of great pressure differences between the interior and exterior.

Corners and flat walls are weak points , so the habitats will have rounded and smooth shapes to handle the stress of great pressure differences between the interior and exterior .


The airlocks need to be very airtight and work perfectly every time.

The airlocks need to be very airtight and work perfectly every time .


Without an extensive magnetosphere or a dense atmosphere, half of all radiation coming from space reaches the ground.

Without an extensive magnetosphere or a dense atmosphere , half of all radiation coming from space reaches the ground .


A person on the surface would be subjected to 50 times the radiation that they would be on Earth.

A person on the surface would be subjected to 50 times the radiation that they would be on Earth .


Three years on the surface of Mars exceeds the radiation dose limits imposed on NASA astronauts for their entire career.

Three years on the surface of Mars exceeds the radiation dose limits imposed on NASA astronauts for their entire career .


This increases cancer risks significantly.

This increases cancer risks significantly .


To prevent that, we could shield our habitats with a thick layer of frozen CO2 that can be harvested directly from the atmosphere.

To prevent that , we could shield our habitats with a thick layer of frozen CO2 that can be harvested directly from the atmosphere .


Covering the dry ice with a meter of dirt would further increase the level of protection.

Covering the dry ice with a meter of dirt would further increase the level of protection .


Sadly, this means almost no windows.


From the inside, most living spaces will be windowless tunnels.

From the inside , most living spaces will be windowless tunnels .


From the outside, they'll look like burial mounds.

From the outside , they 'll look like burial mounds .


All of this would still not hold back all the radiation, but reduce it just enough to be survivable for long periods of time.

All of this would still not hold back all the radiation , but reduce it just enough to be survivable for long periods of time .


It won't, however, protect anyone who ventures outside.

It wo n't , however , protect anyone who ventures outside .


So, remote-controlled robots will be used for routine work on the surface while our crew stays inside.

So , remote - controlled robots will be used for routine work on the surface while our crew stays inside .


Staying inside is a good idea for another reason.

Staying inside is a good idea for another reason .


It's much finer than dust on Earth, so it could find its way into the gears or electronics of our machines.

It 's much finer than dust on Earth , so it could find its way into the gears or electronics of our machines .


Because it's also very dry, it's electrostatically charged, sticking to everything, like spacesuits.

Because it 's also very dry , it 's electrostatically charged , sticking to everything , like spacesuits .


It would be impossible to avoid carrying lots of Mars dust into our habitat and into the lungs of our crew.

It would be impossible to avoid carrying lots of Mars dust into our habitat and into the lungs of our crew .


To make this even worse, Mars' soil is filled with very toxic perchlorate salts.

To make this even worse , Mars ' soil is filled with very toxic perchlorate salts .


Constant exposure could be deadly.


This problem can still be overcome, though.

This problem can still be overcome , though .


Spacesuits, for example, could be made in a way that they never truly enter the base, but stay attached to the outside of the habitats.

Spacesuits , for example , could be made in a way that they never truly enter the base , but stay attached to the outside of the habitats .


Now we've safely isolated humans in terms of energy and air, and protected them from cancer, we just need to feed them.

Now we 've safely isolated humans in terms of energy and air , and protected them from cancer , we just need to feed them .


Water is easy to come by if a settlement is positioned near the Martian poles with their thick layers of ice.

Water is easy to come by if a settlement is positioned near the Martian poles with their thick layers of ice .


Growing food is a different kind of challenge, though.

Growing food is a different kind of challenge , though .


Mars' soils are alkaline and lack the vital nitrogen compounds that plants need to grow.

Mars ' soils are alkaline and lack the vital nitrogen compounds that plants need to grow .


Before we can grow anything, we will have to decontaminate the soil, which is difficult and expensive.

Before we can grow anything , we will have to decontaminate the soil , which is difficult and expensive .


Then the soil can be fertilized using recycled biological waste.

Then the soil can be fertilized using recycled biological waste .


All of this will take a lot of time and is very energy intensive.

All of this will take a lot of time and is very energy intensive .


So we might use aquaponics to raise fish and plants together, making the astronauts' diets more varied and tasty at the same time.

So we might use aquaponics to raise fish and plants together , making the astronauts ' diets more varied and tasty at the same time .


This will be an important psychological boost for our overworked crew.

This will be an important psychological boost for our overworked crew .


All of these things don't solve one fundamental problem, though.

All of these things do n't solve one fundamental problem , though .


Mars has only 38% of Earth's surface gravity, which could cause muscle wasting, bone loss, and cardiovascular problems.

Mars has only 38 % of Earth 's surface gravity , which could cause muscle wasting , bone loss , and cardiovascular problems .


While this might be solved in the future by setting up rotating living spaces, for now, our crew has to live with low gravity and exercise a lot to slow the degradation down.

While this might be solved in the future by setting up rotating living spaces , for now , our crew has to live with low gravity and exercise a lot to slow the degradation down .


The crews will probably have to rotate every few years after being stuck indoors in tight spaces without windows,

The crews will probably have to rotate every few years after being stuck indoors in tight spaces without windows ,


Like Antarctic scientists or submarine staff, they will undergo intense psychological screening to make sure they're mentally resilient enough to handle this lifestyle for several years.

Like Antarctic scientists or submarine staff , they will undergo intense psychological screening to make sure they 're mentally resilient enough to handle this lifestyle for several years .


Establishing the first real infrastructure on Mars will be extremely taxing work that only a group of very determined and competent people can do.

Establishing the first real infrastructure on Mars will be extremely taxing work that only a group of very determined and competent people can do .


Luckily, we have enough of these on Earth.

Luckily , we have enough of these on Earth .


And there you have it, a small Mars base that will survive for at least a few decades, as long as it's getting a constant supply of resources, parts, nuclear fuel, and crews from Earth.

And there you have it , a small Mars base that will survive for at least a few decades , as long as it 's getting a constant supply of resources , parts , nuclear fuel , and crews from Earth .


Unfortunately, Mars and Earth are separated by millions of kilometers and orbital periods that leave only a narrow travel window every two years.

Unfortunately , Mars and Earth are separated by millions of kilometers and orbital periods that leave only a narrow travel window every two years .


If there's an emergency in the colony, Earth wouldn't be able to help until the next travel window opens.

If there 's an emergency in the colony , Earth would n't be able to help until the next travel window opens .


Helpers may arrive on a planet filled with corpses.

Helpers may arrive on a planet filled with corpses .


Settling Mars will be the toughest challenge we have ever faced.

Settling Mars will be the toughest challenge we have ever faced .


It will be gruesome work to establish the infrastructure we need.

It will be gruesome work to establish the infrastructure we need .


But we're stubborn and we like extreme challenges.

But we 're stubborn and we like extreme challenges .


If we push through phase two of colonization, anything is possible.

If we push through phase two of colonization , anything is possible .


Going to Mars is hard, but worth it.


And if we're lucky, we might be around long enough to see it happening and cheer on the people who take on these challenges for the benefit of us all.

And if we 're lucky , we might be around long enough to see it happening and cheer on the people who take on these challenges for the benefit of us all .


Figuring out complex stuff is one of the best feelings ever, especially if you don't have to do it all by yourself.

Figuring out complex stuff is one of the best feelings ever , especially if you do n't have to do it all by yourself .


Our friends from Brilliant can help you out with that part.

Our friends from Brilliant can help you out with that part .


Brilliant is a problem-solving website with a hands-on approach.

Brilliant is a problem - solving website with a hands - on approach .


Instead of just dropping tricky concepts in front of you, they help you unravel them bit by bit and build up to an interesting conclusion.

Instead of just dropping tricky concepts in front of you , they help you unravel them bit by bit and build up to an interesting conclusion .


This way, science becomes something you actually do actively and not only hear about.

This way , science becomes something you actually do actively and not only hear about .


With Brilliant, you can bear down on dozens of interesting courses and puzzles about topics like solar energy, gravity, and astronomy.

With Brilliant , you can bear down on dozens of interesting courses and puzzles about topics like solar energy , gravity , and astronomy .


If you visit brilliant.org/nutshell or click the link in the description, you can sign up for free and learn all kinds of things.

If you visit brilliant.org/nutshell or click the link in the description , you can sign up for free and learn all kinds of things .


And as a bonus for Kurzgesagt viewers, the first 688 people will also get 20% off their annual membership.

And as a bonus for Kurzgesagt viewers , the first 688 people will also get 20 % off their annual membership .


With Brilliant, you finish your day a little bit smarter.

With Brilliant , you finish your day a little bit smarter .


And no Mars dust to deal with, we promise.

And no Mars dust to deal with , we promise .


Can't get enough of Mars?


We've also made a poster about it.


You can learn some more about the hardships of Mars colonization or just look at the pretty colors.

You can learn some more about the hardships of Mars colonization or just look at the pretty colors .


Your tattoos are inside your immune system, literally.

Your tattoos are inside your immune system , literally .


With each very tasteful piece of art, you kickstart a drama with millions of deaths, grand sacrifices and your immune system stepping in to protect you from yourself.

With each very tasteful piece of art , you kickstart a drama with millions of deaths , grand sacrifices and your immune system stepping in to protect you from yourself .


Let's give you a tattoo and zoom in to see what happens inside your skin.

Let 's give you a tattoo and zoom in to see what happens inside your skin .


Your skin has to solve a huge problem.


It's your largest organ and has the most direct contact with the world around you.

It 's your largest organ and has the most direct contact with the world around you .


Trillions of microbes, dirt, insects and vermin can't be allowed to get inside you.

Trillions of microbes , dirt , insects and vermin ca n't be allowed to get inside you .


But your skin is also constantly damaged by you moving through the world.

But your skin is also constantly damaged by you moving through the world .


Your body solved this by making your skin a conveyor belt of death.

Your body solved this by making your skin a conveyor belt of death .


All the skin you see is actually dead stuff.

All the skin you see is actually dead stuff .


The alive part of your skin cells begins around one millimeter deep in the skin industrial complex.

The alive part of your skin cells begins around one millimeter deep in the skin industrial complex .


Stem cells constantly clone themselves, producing new skin cells that begin a journey from the inside to the outside.

Stem cells constantly clone themselves , producing new skin cells that begin a journey from the inside to the outside .


Each new generation pushes the older ones further up.

Each new generation pushes the older ones further up .


As your skin cells mature, they interlock with each other and produce laminar bodies.

As your skin cells mature , they interlock with each other and produce laminar bodies .


And then they dry out and kill themselves, merging together into inseparable lumps.

And then they dry out and kill themselves , merging together into inseparable lumps .


This wall of dead corpses is consistently pushed upwards.

This wall of dead corpses is consistently pushed upwards .


Up to 50 layers of dead cells cover your whole body and are constantly replaced by new cells moving up.

Up to 50 layers of dead cells cover your whole body and are constantly replaced by new cells moving up .


Every hour, you shed around 200 million dead skin cells and all the dirt or bacteria that are stuck to them.

Every hour , you shed around 200 million dead skin cells and all the dirt or bacteria that are stuck to them .


Tattooing this part of your skin would be useless as nothing would stick around.

Tattooing this part of your skin would be useless as nothing would stick around .


We need to go deeper.


Below the conveyor belt of death lies the dermis.

Below the conveyor belt of death lies the dermis .


It's full of structural tissue and cells.

It 's full of structural tissue and cells .


This region and below is where your new tattoo will go.

This region and below is where your new tattoo will go .


The world explodes.


Half a dozen monoliths the size of skyscrapers slam through the 50 layers of dead cells deep into the dermis, ripping huge holes into the skin.

Half a dozen monoliths the size of skyscrapers slam through the 50 layers of dead cells deep into the dermis , ripping huge holes into the skin .


Tens of thousands of cells are violently killed right away, ripped into pieces or damaged beyond repair.

Tens of thousands of cells are violently killed right away , ripped into pieces or damaged beyond repair .


Luckily, you did your research and chose a responsible tattoo artist who properly disinfected their tools and your skin.

Luckily , you did your research and chose a responsible tattoo artist who properly disinfected their tools and your skin .


But you only ever get 99.9% of all bacteria and some of the survivors made it into your flesh.

But you only ever get 99.9 % of all bacteria and some of the survivors made it into your flesh .


To put it mildly, your immune system is not amused at all.

To put it mildly , your immune system is not amused at all .


All the death and destruction wakes up hundreds of thousands of macrophages in your dermis that rush into the open wounds to defend you.

All the death and destruction wakes up hundreds of thousands of macrophages in your dermis that rush into the open wounds to defend you .


Immediately, they start killing bacteria, release chemicals that call for reinforcements, and order your blood vessels to open up and make your dermis swell up with fluid.

Immediately , they start killing bacteria , release chemicals that call for reinforcements , and order your blood vessels to open up and make your dermis swell up with fluid .


But worse than the hundreds of wounds and a few invaders is the tidal wave of chemicals that floods your tissue.

But worse than the hundreds of wounds and a few invaders is the tidal wave of chemicals that floods your tissue .


Tattoo ink can be made from hundreds of substances.

Tattoo ink can be made from hundreds of substances .


Some may even be toxic or carcinogenic.

Some may even be toxic or carcinogenic .


Most are from heavy metals like lead, nickel, or chromium dissolved in distilled water.

Most are from heavy metals like lead , nickel , or chromium dissolved in distilled water .


The battlefield is now a wild mix of dead cell parts, a few panicked bacteria, blood and bodily fluids, platelet cells trying to close wounds, more and more fresh immune cells, and the flood of tattoo ink.

The battlefield is now a wild mix of dead cell parts , a few panicked bacteria , blood and bodily fluids , platelet cells trying to close wounds , more and more fresh immune cells , and the flood of tattoo ink .


On the scale of your cells, clumps of ink particles are huge.

On the scale of your cells , clumps of ink particles are huge .


If you were the size of a cell, they'd range from big dogs to small office buildings.

If you were the size of a cell , they 'd range from big dogs to small office buildings .


Your immune system has one main job.


Identify what is not you and smash it until it's dead.

Identify what is not you and smash it until it 's dead .


The macrophages are desperately trying to do that.

The macrophages are desperately trying to do that .


Like tiny octopuses, they extend arm-like structures and begin pulling the ink particles inside.

Like tiny octopuses , they extend arm - like structures and begin pulling the ink particles inside .


Usually, when a macrophage has eaten an enemy, it showers it in acid to dissolve it.

Usually , when a macrophage has eaten an enemy , it showers it in acid to dissolve it .


But this doesn't work with the ink.


They try and try, but nothing works.


The particles don't react in any way.


And this is just the particles small enough to be devoured.

And this is just the particles small enough to be devoured .


By now, the larger chunks are surrounded by thousands of your structural skin cells and macrophages that are nomming on them, bathing them in acid and attack chemicals, trying to destroy and kill them.

By now , the larger chunks are surrounded by thousands of your structural skin cells and macrophages that are nomming on them , bathing them in acid and attack chemicals , trying to destroy and kill them .


But they're not moving even a tiny bit.

But they 're not moving even a tiny bit .


Nothing works.


Finally, your immune system has to concede.

Finally , your immune system has to concede .


It will not win this fight, so it does the next best thing, not lose.

It will not win this fight , so it does the next best thing , not lose .


Your cells don't know how dangerous these metals and chemicals are, but they can at least not let them spread around.

Your cells do n't know how dangerous these metals and chemicals are , but they can at least not let them spread around .


So they just stay in place.


They vacuum all the particles they can fit into their bodies, and surround the larger ones, trapping them in the only prison they can build, themselves.

They vacuum all the particles they can fit into their bodies , and surround the larger ones , trapping them in the only prison they can build , themselves .


Bit by bit, the ink inside thousands of tiny wounds moves inside millions of immune cells that freeze in place forever.

Bit by bit , the ink inside thousands of tiny wounds moves inside millions of immune cells that freeze in place forever .


On the outside, you don't notice any of this.

On the outside , you do n't notice any of this .


Your new tattoo is fresh and the colors are vibrant.

Your new tattoo is fresh and the colors are vibrant .


Your skin hurts and is irritated and swollen.

Your skin hurts and is irritated and swollen .


But wounds heal, tiny holes close, dead cells are replaced.

But wounds heal , tiny holes close , dead cells are replaced .


Bit by bit, the conveyor belt of death does its job, shedding dead cells ripe in color, replacing them with fresh and clean ones.

Bit by bit , the conveyor belt of death does its job , shedding dead cells ripe in color , replacing them with fresh and clean ones .


Your tattoo becomes a little less vibrant, now the ink is no longer on your skin, but inside it.

Your tattoo becomes a little less vibrant , now the ink is no longer on your skin , but inside it .


But what you're really seeing is millions of your macrophages sitting in your dermis, patiently holding the ink in place, protecting your body from poison.

But what you 're really seeing is millions of your macrophages sitting in your dermis , patiently holding the ink in place , protecting your body from poison .


Your immune system is why your tattoo is forever.

Your immune system is why your tattoo is forever .


Actually, nothing is forever.


Over time, your macrophages get old and die, and new ones come in to gobble up the ink and keep it in place.

Over time , your macrophages get old and die , and new ones come in to gobble up the ink and keep it in place .


But sometimes, a tiny bit of ink escapes.

But sometimes , a tiny bit of ink escapes .


Most of it is recaptured and locked in place, but not always the exact same place.

Most of it is recaptured and locked in place , but not always the exact same place .


You notice that as your tattoo fades out a bit and turns less sharp and crisp at its edges.

You notice that as your tattoo fades out a bit and turns less sharp and crisp at its edges .


Some of the ink escapes the tattoo entirely.

Some of the ink escapes the tattoo entirely .


It rides fluids flowing from your tissue and spreads around your body, another reason why tattoo ink should ideally not be poison.

It rides fluids flowing from your tissue and spreads around your body , another reason why tattoo ink should ideally not be poison .


Your immune system also kind of doesn't want you to remove tattoos.

Your immune system also kind of does n't want you to remove tattoos .


To do that, usually the ink is shot at with lasers, which heats up the particles until they break into smaller chunks, cooking your brave macrophages in the process.

To do that , usually the ink is shot at with lasers , which heats up the particles until they break into smaller chunks , cooking your brave macrophages in the process .


With every round of lasering, more of your tattoo is broken down and carried away by fluids.

With every round of lasering , more of your tattoo is broken down and carried away by fluids .


But also, every time, new macrophages rush into the tattoo to lock the ink in place.

But also , every time , new macrophages rush into the tattoo to lock the ink in place .


So like, hmm, maybe think about it carefully before you get the name of your new bae tattooed.

So like , hmm , maybe think about it carefully before you get the name of your new bae tattooed .


But you do you.


But if you got one, you can directly see your immune system protecting you.

But if you got one , you can directly see your immune system protecting you .


This is how much your body loves you, which is kind of sweet.

This is how much your body loves you , which is kind of sweet .


you now know about the struggle going on inside your skin and the sacrifice of your macrophage buddies, only for you to have that art forever.

you now know about the struggle going on inside your skin and the sacrifice of your macrophage buddies , only for you to have that art forever .


To appreciate your amazing immune system, you have to know about it first.

To appreciate your amazing immune system , you have to know about it first .


And the same goes for anything going on in our universe.

And the same goes for anything going on in our universe .


To help you with that, we've created a series of lessons to take your scientific knowledge to the next level.

To help you with that , we 've created a series of lessons to take your scientific knowledge to the next level .


Made in collaboration with our friends at Brilliant.org, these lessons let you further explore the topics in our most popular videos, from rabies and mammalian metabolism to climate science and supernovae.

Made in collaboration with our friends at Brilliant.org , these lessons let you further explore the topics in our most popular videos , from rabies and mammalian metabolism to climate science and supernovae .


Brilliant has thousands of lessons to explore, and each one is interactive, like a one-on-one version of a Kurzgesagt video.

Brilliant has thousands of lessons to explore , and each one is interactive , like a one - on - one version of a Kurzgesagt video .


Brilliant's latest course, How LLMs Work, takes you under the hood of real language models.

Brilliant 's latest course , How LLMs Work , takes you under the hood of real language models .


It demystifies technologies like ChatGPT with interactive lessons on everything from how models build vocabulary to how they choose their next word.

It demystifies technologies like ChatGPT with interactive lessons on everything from how models build vocabulary to how they choose their next word .


You'll learn how to tune LLMs to produce output with exactly your desired tonality, whether it's poetry or a cover letter.

You 'll learn how to tune LLMs to produce output with exactly your desired tonality , whether it 's poetry or a cover letter .


And you'll understand why training is really everything by comparing models trained on Taylor Swift lyrics and legal speech of Big Tech's Terms and Conditions.

And you 'll understand why training is really everything by comparing models trained on Taylor Swift lyrics and legal speech of Big Tech 's Terms and Conditions .


This isn't just another course, it's an immersive AI workshop, allowing you to experience and harness the mechanics of today's most advanced tool.

This is n't just another course , it 's an immersive AI workshop , allowing you to experience and harness the mechanics of today 's most advanced tool .


To get hands-on with Kurzgesagt lessons and explore everything Brilliant has to offer, you can start your free 30-day trial by signing up at brilliant.org/nutshell.

To get hands - on with Kurzgesagt lessons and explore everything Brilliant has to offer , you can start your free 30 - day trial by signing up at brilliant.org/nutshell .


There's even an extra perk for Kurzgesagt viewers.

There 's even an extra perk for Kurzgesagt viewers .


The first 200 people to use the link get 20% off an annual membership once their trial ends.

The first 200 people to use the link get 20 % off an annual membership once their trial ends .


We love seeing how the gears interlock with our research.

We love seeing how the gears interlock with our research .


Brilliant gives you the tools to understand how everything fits together.

Brilliant gives you the tools to understand how everything fits together .


Never before in human history have we been richer, more advanced, more powerful.

Never before in human history have we been richer , more advanced , more powerful .


And yet, we feel overwhelmed in the face of rapid climate change.

And yet , we feel overwhelmed in the face of rapid climate change .


It seems simple on the surface.


Greenhouse gases trap energy from the sun and transfer it to our atmosphere.

Greenhouse gases trap energy from the sun and transfer it to our atmosphere .


This leads to warmer winters, harsher summers.

This leads to warmer winters , harsher summers .


Dry places become drier and wet places wetter.

Dry places become drier and wet places wetter .


Countless ecosystems will die while the rising oceans swallow coasts and the cities we build on them.

Countless ecosystems will die while the rising oceans swallow coasts and the cities we build on them .


Well, it's complicated.


The public debate about stopping rapid climate change often focuses on a few key features, like coal plants, cars or burping cows.

The public debate about stopping rapid climate change often focuses on a few key features , like coal plants , cars or burping cows .


And so the solutions are often simplistic.

And so the solutions are often simplistic .


And a huge talking point is personal responsibility.

And a huge talking point is personal responsibility .


How you should change your lifestyle to prevent rapid climate change, which we'll find out together in the next few minutes.

How you should change your lifestyle to prevent rapid climate change , which we 'll find out together in the next few minutes .


This is one of those videos where we want to encourage you to watch to the end,

This is one of those videos where we want to encourage you to watch to the end ,


because to discuss real doable solutions, we first need to understand the problem.

because to discuss real doable solutions , we first need to understand the problem .


Modern industrial society as we constructed it in the last 150 years is inherently destructive to the planet.

Modern industrial society as we constructed it in the last 150 years is inherently destructive to the planet .


Basically, everything we do to make our lives easier, safer and more comfortable is making things worse for the biosphere.

Basically , everything we do to make our lives easier , safer and more comfortable is making things worse for the biosphere .


While most people know about the serious impact of energy, beef, cars and planes, many major polluters are barely ever talked about.

While most people know about the serious impact of energy , beef , cars and planes , many major polluters are barely ever talked about .


The emissions leaking out of landfills are as significant as the emissions of all the jets in the air.

The emissions leaking out of landfills are as significant as the emissions of all the jets in the air .


More CO2 is released to run our homes than from all cars combined.

More CO2 is released to run our homes than from all cars combined .


And the emissions produced when making a new car is equivalent to building just two meters of road.

And the emissions produced when making a new car is equivalent to building just two meters of road .


So it is nice to switch to electric cars, but they won't solve anything if we keep building roads the same way.

So it is nice to switch to electric cars , but they wo n't solve anything if we keep building roads the same way .


Fixing one small part of the industrial system is not enough.

Fixing one small part of the industrial system is not enough .


Each of the many different parts needs its own solution and many of them aren't straightforward.

Each of the many different parts needs its own solution and many of them are n't straightforward .


But even where we know what to do, just because a solution exists, doesn't mean we're able or willing to implement it.

But even where we know what to do , just because a solution exists , does n't mean we 're able or willing to implement it .


There are many grey areas in the fight against rapid climate change.

There are many grey areas in the fight against rapid climate change .


The most prominent one is the divide between rich and poor.

The most prominent one is the divide between rich and poor .


There is a clear connection between the prosperity of a nation and its carbon emissions.

There is a clear connection between the prosperity of a nation and its carbon emissions .


In other words, richer people tend to cause more emissions.

In other words , richer people tend to cause more emissions .


While this would help, it wouldn't make the problem go away.

While this would help , it would n't make the problem go away .


This is because 63% of global emissions come from low to middle-income countries.

This is because 63 % of global emissions come from low to middle - income countries .


The unfortunate reality is that currently, escaping poverty and becoming middle class creates unavoidable emissions.

The unfortunate reality is that currently , escaping poverty and becoming middle class creates unavoidable emissions .


So asking developing countries to cut emissions just looks like an attempt to keep them down.

So asking developing countries to cut emissions just looks like an attempt to keep them down .


It's very hard to argue that a region should protect their primeval forests and spend money on soda panels instead of burning wood

It 's very hard to argue that a region should protect their primeval forests and spend money on soda panels instead of burning wood


But cutting back is not a popular demand, especially if the countries making these demands got rich by causing environmental damage in the past.

But cutting back is not a popular demand , especially if the countries making these demands got rich by causing environmental damage in the past .


So for billions of people, more emissions are a good thing, personally.

So for billions of people , more emissions are a good thing , personally .


When we forget about this, we tend to propose unworkable solutions.

When we forget about this , we tend to propose unworkable solutions .


Take concrete.


8% of CO2 emissions are released by the concrete manufacturing industry.

8 % of CO2 emissions are released by the concrete manufacturing industry .


But right now, concrete is also a cheap and easy way for growing populations in developing countries to build affordable housing.

But right now , concrete is also a cheap and easy way for growing populations in developing countries to build affordable housing .


And there are many examples like that.


Even rich countries aren't immune from disagreeing about rapid climate change solutions,

Even rich countries are n't immune from disagreeing about rapid climate change solutions ,


Citizens can be strictly against nuclear power, but also oppose wind or solar infrastructure in their backyards.

Citizens can be strictly against nuclear power , but also oppose wind or solar infrastructure in their backyards .


In principle, all of these issues can be overcome, but there are things we don't currently know how to overcome.

In principle , all of these issues can be overcome , but there are things we do n't currently know how to overcome .


The most problematic one is food.


Emit or die.


We will soon need to feed 10 billion people, and we don't know how to do that without emitting greenhouse gases.

We will soon need to feed 10 billion people , and we do n't know how to do that without emitting greenhouse gases .


Because of the nature of modern food production that requires fertilizers or manure, it's impossible to have zero emissions food.

Because of the nature of modern food production that requires fertilizers or manure , it 's impossible to have zero emissions food .


Rice alone emits so much methane each year that it practically equals the emissions of all the air traffic in the world.

Rice alone emits so much methane each year that it practically equals the emissions of all the air traffic in the world .


What's worse is that the foods we like the most emit the most.

What 's worse is that the foods we like the most emit the most .


57% of food emissions come from animal-based foods, although they make up only 18% of the world's calories and 37% of its protein.

57 % of food emissions come from animal - based foods , although they make up only 18 % of the world 's calories and 37 % of its protein .


And as people across the world grow richer, they want more meat.

And as people across the world grow richer , they want more meat .


Traditional diets in most cultures were primarily plant-based with a little meat on top.

Traditional diets in most cultures were primarily plant - based with a little meat on top .


But with the rise of industrial-style meat production and factory farming, meat has become a staple food.

But with the rise of industrial - style meat production and factory farming , meat has become a staple food .


Today, about 40% of the world's habitable land is used for meat production in some form or another, the size of North and South America combined.

Today , about 40 % of the world 's habitable land is used for meat production in some form or another , the size of North and South America combined .


This is land we could otherwise allow native ecosystems to regrow, like forests in the Amazon, and suck carbon out of the atmosphere.

This is land we could otherwise allow native ecosystems to regrow , like forests in the Amazon , and suck carbon out of the atmosphere .


But instead, most of it is used to feed animals.

But instead , most of it is used to feed animals .


The available solutions are uniquely able to make everybody on the political spectrum, rich or poor, unhappy.

The available solutions are uniquely able to make everybody on the political spectrum , rich or poor , unhappy .


Meat is highly emotional and there are a lot of what-aboutism arguments floating around, like comparing it to the worst sources of emissions.

Meat is highly emotional and there are a lot of what - aboutism arguments floating around , like comparing it to the worst sources of emissions .


In the end, it's pretty simple.


Eating less meat alone won't stop climate change, but we also can't stop climate change without eating less meat.

Eating less meat alone wo n't stop climate change , but we also ca n't stop climate change without eating less meat .


The same holds true for other things that are less crucial to our survival, but frankly not realistic to make go away.

The same holds true for other things that are less crucial to our survival , but frankly not realistic to make go away .


So what does this mean?


Do we need to give up our way of life and can the poor never achieve it?

Do we need to give up our way of life and can the poor never achieve it ?


Can't some technology save us so we can continue to drive our big cars and eat meat every day?

Ca n't some technology save us so we can continue to drive our big cars and eat meat every day ?


In principle, this technology already exists.

In principle , this technology already exists .


Direct air capture of CO2 draws carbon dioxide from the air so that it can be stored underground or transformed into products.

Direct air capture of CO2 draws carbon dioxide from the air so that it can be stored underground or transformed into products .


So why aren't we implementing it in every industry everywhere?

So why are n't we implementing it in every industry everywhere ?


Because with the technology we have right now, this would cost some 10 trillion dollars per year or half the United States GDP.

Because with the technology we have right now , this would cost some 10 trillion dollars per year or half the United States GDP .


This money has to come from somewhere and currently no one is offering it.

This money has to come from somewhere and currently no one is offering it .


Just dumping these costs on massive polluters like steel mills and coal power stations would double the cost of their products


and so these industries that operate on very tight profit margins would go bankrupt.

and so these industries that operate on very tight profit margins would go bankrupt .


Getting the government to pay for it seems logical, but a lot of state resources are actually tied up doing the opposite like subsidizing oil and gas,

Getting the government to pay for it seems logical , but a lot of state resources are actually tied up doing the opposite like subsidizing oil and gas ,


By artificially keeping fuel prices low, shipping and everyday goods are kept artificially cheap too,

By artificially keeping fuel prices low , shipping and everyday goods are kept artificially cheap too ,


That creates political lobbies and incentives that perpetuate a cycle that makes it so hard to stop fossil fuel production.

That creates political lobbies and incentives that perpetuate a cycle that makes it so hard to stop fossil fuel production .


Meanwhile, very costly solutions for a far-off problem like carbon capture seem like they can wait as technically nobody benefits from it right now.

Meanwhile , very costly solutions for a far - off problem like carbon capture seem like they can wait as technically nobody benefits from it right now .


Some argue that a move away from capitalism is the only solution to this mess,

Some argue that a move away from capitalism is the only solution to this mess ,


others insist that markets should be even freer without any interventions like subsidies,

others insist that markets should be even freer without any interventions like subsidies ,


and some suggest that we need what's referred to as degrowth and to cut back as a species overall.

and some suggest that we need what 's referred to as degrowth and to cut back as a species overall .


But the truth is, at least as of now, no political system is doing an impressive job at becoming truly sustainable and none have really done so in the past.

But the truth is , at least as of now , no political system is doing an impressive job at becoming truly sustainable and none have really done so in the past .


We also don't have the time to figure this out and do a lot of experiments.

We also do n't have the time to figure this out and do a lot of experiments .


We must implement solutions now, not just to halt the release of all possible greenhouse gases, but also to start reducing the amount of CO2 in the air.

We must implement solutions now , not just to halt the release of all possible greenhouse gases , but also to start reducing the amount of CO2 in the air .


It's too late to just mend our ways, we have to actively correct our past mistakes.

It 's too late to just mend our ways , we have to actively correct our past mistakes .


With every year we waste, more extreme changes will be unavoidable.

With every year we waste , more extreme changes will be unavoidable .


Okay, let's take a deep breath.


Rapid climate change and the world we live in are complicated, so here is where you, dear viewer, come in again.

Rapid climate change and the world we live in are complicated , so here is where you , dear viewer , come in again .


A narrative of our time is that we are all responsible for rapid climate change, that everyone needs to play their part.

A narrative of our time is that we are all responsible for rapid climate change , that everyone needs to play their part .


Why don't you buy a new electric car?


Why don't you replace your gas stove with an electric one?

Why do n't you replace your gas stove with an electric one ?


How about you double-glaze your windows, stop eating meat and switch off your lights?

How about you double - glaze your windows , stop eating meat and switch off your lights ?


Shifting responsibility from the largest carbon emitters to the average person, you, is much easier to do than solving problems.

Shifting responsibility from the largest carbon emitters to the average person , you , is much easier to do than solving problems .


There's an extra bonus if solving rapid climate change sells a new product.

There 's an extra bonus if solving rapid climate change sells a new product .


If you don't have the money or time for these things, you should feel bad.

If you do n't have the money or time for these things , you should feel bad .


It's an effective message because it's true.

It 's an effective message because it 's true .


The quickest way to cut CO2 emissions would be if all rich populations on Earth drastically changed their lifestyles


If you're able to watch this video, that includes you.

If you 're able to watch this video , that includes you .


But we've just witnessed a global experiment in staying at home, not using transport and consuming less during the coronavirus pandemic.

But we 've just witnessed a global experiment in staying at home , not using transport and consuming less during the coronavirus pandemic .


And all it did was reduce CO2 emissions by 7% for 2020.

And all it did was reduce CO2 emissions by 7 % for 2020 .


Asking average people to solve rapid climate change breaks down when we look at the scale of the problem.

Asking average people to solve rapid climate change breaks down when we look at the scale of the problem .


Personal contributions towards reducing greenhouse gas emissions are nice, but they are dwarfed by the systemic reality of global emissions.

Personal contributions towards reducing greenhouse gas emissions are nice , but they are dwarfed by the systemic reality of global emissions .


The concept of your personal carbon footprint was popularised by the oil producer BP in a 2005 ad campaign.

The concept of your personal carbon footprint was popularised by the oil producer BP in a 2005 ad campaign .


If you eliminated 100% of your emissions for the rest of your life, you would save one second's worth of emissions from the global energy sector.

If you eliminated 100 % of your emissions for the rest of your life , you would save one second 's worth of emissions from the global energy sector .


Even the most motivated person can't even make a tiny dent.

Even the most motivated person ca n't even make a tiny dent .