<p>First of all, earth doesn't have the same atmosphere it had, back when dinosaurs walked the earth, when most of current carbon-deposits formed. Some atmospheres earth had would even be toxic to humans. So, you're right, changing the atmosphere at the speed we're doing it is the problem, not the change in general.</p>

<hr>

<p>Second, yes, earth is a rather closed system (with minor leaks, but anyway). Still, the timescale is important.</p>

<p>Let's go with a simple allegory:</p>

<p>Say, your friend had a pickup-truck (sorry, in my mind deniers all drive SUV or pickup^^). He uses it to transport a lot of material, e.g. paving stones. He knows, his truck is able to transport the total amount of stones (because he tried in the past, or because the specifications say so, or because someone told him, doesn't matter - like we know that earth's atmosphere held a lot more CO2 back in the day).</p>

<p>Is he going to just dump the whole load at once from 2 m height into the back of his truck? I doubt so, because that would at least put some dents in the truck, or might even break the springs or an axle.</p>

<p>He'd pack the stones there manually and use enough padding to make sure nothing gets damaged or slips during the transport.</p>

<p>Currently we're dumping the stones all at once - and we'll surely break the vehicle, if we really continue. Earth, like the truck, needs to adapt to changes. And, as we know, geological timescales are a lot longer than we can truly observe - thus the current changes, though stretching over several generations, are way too fast for earth to really adapt.</p>

<hr>

<p>Third: While earth is a closed system, states within a closed system may change. Say, you have a terrarium with some mice and a lot of wood. Then you burn the wood. The mice might survive the fire, but in the end will suffocate, since there is a lot more CO2 in their atmosphere now.</p>

<p>So, yes, releasing trapped carbon from fossile fuels and whatnot to the atmosphere doesn't change the overall mass of system earth. But it changes the state of the system - and we are depending on the current state of the system.</p>

<hr>

<p>Also - I know, this is not scientifically - say we are wrong when it comes to greenhouse gasses, and he is right. What if we undertook a lot of effort to not to produce them, to clean our environment, to create less waste? We'd wake up one morning and be "Dang, we made our planet worth living on again, how could we?!" - Or, as one of my professors put it: "Would you get on a plane when there is a 10 % chance, the plane is going to crash?"</p>

CC BY-SA 4.0
2022-05-25T14:29:49.397Z
Playing with your pick up analogy. Your friend is contracted to deliver paving stones from the quarry to a building site.  Each year the quarry increases production. Now he can load his truck up a bit more, drive a bit faster, but eventually he can't keep up and the pile of stones at the quarry starts to grow. The amount of stone in the world hasn't changed, but the pile of paving stones is getting bigger and bigger.
Andy M
CC BY-SA 4.0
2019-04-26T07:56:05.783Z
2019-04-26T07:56:05.783Z
Erik
<p>The total amount of carbon is constant, the total amount of CO2 rises, mainly due to the burning of fossil fuels. </p>

CC BY-SA 4.0
2019-05-01T20:38:06.177Z
2019-05-01T20:38:06.177Z
Basileios
<p><strong>If you put a blanket around yourself, you warm up.</strong></p>

<p>Sounds a bit silly, but this is the physics of GHG warming in a nutshell.
The atmosphere is transparent to optical radiation which provides nearly all the energy to be trapped.<br>
Therefore, when computing a GHG model, you can put the source of the heating actually onto the surface of Earth. The energy is then reprocessed into infrared radiation and tries to escape.</p>

<p>In this situation, both your body and the Earths atmosphere try to radiate in the infrared, but with a blanket that heat cannot escape anymore.
No matter if the blanket was laying around somewhere else for thousands of years, in that moment it gets warm.</p>

<p>This is of course a flawed <strong>analogy</strong>, the better one is the one of the greenhouse: Visible light can enter, providing heat, but cannot escape in the infrared, because the glass is intransparent to infrared.
The more <span class="math-container">$\rm CO_2$</span> there is in the atmosphere, the more 'glass'. No matter if this glass was buried underground for ages, at this very moment it causes temperatures to rise enormously.<br>
Same story with why a car heats up into a death trap in summer, while the exterior of the car at the same moment doesn't.</p>

<p>Your friend (and probably other climate denialists) confuse the Earth's mass balance with its energy balance. One doesn't have much to do with the other.</p>

CC BY-SA 4.0
2019-05-01T21:27:18.290Z
2019-05-01T21:35:57.990Z
2019-05-01T21:35:57.990Z
AtmosphericPrisonEscape
<p>Something else to consider: the amount of energy we get from the sun is slowly increasing over the billions of years as the sun goes through its lifecycle, so when you go back to ancient atmospheres and find what we would consider very high concentrations of GHG like CO2, it was necessary at that time to keep the planet warm. You can't simply look at the atmosphere from half a billion years ago and compare it with the present without considering the solar output.</p>

CC BY-SA 4.0
2019-05-03T07:23:50.013Z
2019-05-03T07:23:50.013Z
rchuso
<p>I've got a friend who is a climate change sceptic.</p>
<p>He argues that because all the CO<sub>2</sub> in fossil fuels originally came from the earth's atmosphere. Then there can't be a problem releasing the CO<sub>2</sub> back into the same atmosphere.</p>
<p>Intuitively it seems obvious to me that the quantities CO<sub>2</sub> was stored up over a long time and now is being released back into the atmosphere in just a few short decades, which is causing problems, but his counter is that the earth is a closed system and so the total amount of carbon CO<sub>2</sub> is constant. This part I'm less sure on but I have a feeling he must be wrong on that too.</p>
<p>Can someone please explain where the flaw is his logic is? I want to debunk this in as scientifically accurate as way as possible.</p>

CC BY-SA 4.0
2019-04-26T10:08:58.740Z
It sounds to me like you've been lured into a debate about the details of the Earth science without agreeing what constitutes "a problem".  No amount of evidence can counter-argue or convince someone from a position they haven't defined.  Your friend probably hasn't even decided their position internally, and will just define and redefine it to remain not explained by your evidence.  This is a rhetorical tactic rather than a logical flaw: the implicit straw man.
Deditos
CC BY-SA 4.0
2019-04-26T10:59:58.817Z
The answer below is detailed. However is not true that all the CO2 sequestered by fossil was once there all together, if we consider this world.   Tell you friend that the world we are currently inhabiting was formed right by CO2 sequestration, which likely started by marine microorganisms and before plants. Putting the reasoning in the right mass and time scale should evidence that is argument is very poor, at least poorer than what the answer by @Erik suggests (answer that I up vote, by the way). At best your friend is right that the entire process might restart (but not given).
Alchimista
CC BY-SA 4.0
2019-04-29T21:36:49.283Z
The total amount of carbon is constant but obviously when you dig up coal and burn it you increase the CO2.
Keith McClary
CC BY-SA 4.0
2022-05-25T21:11:08.827Z
there were also jungle temperatures in Antarctica when that coal went into the ground.
John
<climate-change><co2>
Total CO$_2$ is not constant?
user16756
# Total CO$_2$ is not constant?

(Asked by: username_0 on 2019-04-25)

I've got a friend who is a climate change sceptic.

He argues that because all the CO2 in fossil fuels originally came from the earth's atmosphere. Then there can't be a problem releasing the CO2 back into the same atmosphere.

Intuitively it seems obvious to me that the quantities CO2 was stored up over a long time and now is being released back into the atmosphere in just a few short decades, which is causing problems, but his counter is that the earth is a closed system and so the total amount of carbon CO2 is constant. This part I'm less sure on but I have a feeling he must be wrong on that too.

Can someone please explain where the flaw is his logic is? I want to debunk this in as scientifically accurate as way as possible.

**Tags:** climate-change, co2

> **Comments:**
> **username_1**: It sounds to me like you've been lured into a debate about the details of the Earth science without agreeing what constitutes "a problem".  No amount of evidence can counter-argue or convince someone from a position they haven't defined.  Your friend probably hasn't even decided their position internally, and will just define and redefine it to remain not explained by your evidence.  This is a rhetorical tactic rather than a logical flaw: the implicit straw man.  
> **username_2**: The answer below is detailed. However is not true that all the CO2 sequestered by fossil was once there all together, if we consider this world.   Tell you friend that the world we are currently inhabiting was formed right by CO2 sequestration, which likely started by marine microorganisms and before plants. Putting the reasoning in the right mass and time scale should evidence that is argument is very poor, at least poorer than what the answer by @username_5 suggests (answer that I up vote, by the way). At best your friend is right that the entire process might restart (but not given).  
> **username_3**: The total amount of carbon is constant but obviously when you dig up coal and burn it you increase the CO2.  
> **username_4**: there were also jungle temperatures in Antarctica when that coal went into the ground.  

---

## 4 answers

### Answer by username_5 on 2019-04-26. Score: 5

First of all, earth doesn't have the same atmosphere it had, back when dinosaurs walked the earth, when most of current carbon-deposits formed. Some atmospheres earth had would even be toxic to humans. So, you're right, changing the atmosphere at the speed we're doing it is the problem, not the change in general.

---

Second, yes, earth is a rather closed system (with minor leaks, but anyway). Still, the timescale is important.

Let's go with a simple allegory:

Say, your friend had a pickup-truck (sorry, in my mind deniers all drive SUV or pickup^^). He uses it to transport a lot of material, e.g. paving stones. He knows, his truck is able to transport the total amount of stones (because he tried in the past, or because the specifications say so, or because someone told him, doesn't matter - like we know that earth's atmosphere held a lot more CO2 back in the day).

Is he going to just dump the whole load at once from 2 m height into the back of his truck? I doubt so, because that would at least put some dents in the truck, or might even break the springs or an axle.

He'd pack the stones there manually and use enough padding to make sure nothing gets damaged or slips during the transport.

Currently we're dumping the stones all at once - and we'll surely break the vehicle, if we really continue. Earth, like the truck, needs to adapt to changes. And, as we know, geological timescales are a lot longer than we can truly observe - thus the current changes, though stretching over several generations, are way too fast for earth to really adapt.

---

Third: While earth is a closed system, states within a closed system may change. Say, you have a terrarium with some mice and a lot of wood. Then you burn the wood. The mice might survive the fire, but in the end will suffocate, since there is a lot more CO2 in their atmosphere now.

So, yes, releasing trapped carbon from fossile fuels and whatnot to the atmosphere doesn't change the overall mass of system earth. But it changes the state of the system - and we are depending on the current state of the system.

---

Also - I know, this is not scientifically - say we are wrong when it comes to greenhouse gasses, and he is right. What if we undertook a lot of effort to not to produce them, to clean our environment, to create less waste? We'd wake up one morning and be "Dang, we made our planet worth living on again, how could we?!" - Or, as one of my professors put it: "Would you get on a plane when there is a 10 % chance, the plane is going to crash?"

> **Comments:**
> **username_6**: Playing with your pick up analogy. Your friend is contracted to deliver paving stones from the quarry to a building site.  Each year the quarry increases production. Now he can load his truck up a bit more, drive a bit faster, but eventually he can't keep up and the pile of stones at the quarry starts to grow. The amount of stone in the world hasn't changed, but the pile of paving stones is getting bigger and bigger.  

---

### Answer by username_7 on 2019-05-01. Score: 5

The total amount of carbon is constant, the total amount of CO2 rises, mainly due to the burning of fossil fuels.


---

### Answer by username_8 on 2019-05-01. Score: 2

**If you put a blanket around yourself, you warm up.**

Sounds a bit silly, but this is the physics of GHG warming in a nutshell.
The atmosphere is transparent to optical radiation which provides nearly all the energy to be trapped.  
Therefore, when computing a GHG model, you can put the source of the heating actually onto the surface of Earth. The energy is then reprocessed into infrared radiation and tries to escape.

In this situation, both your body and the Earths atmosphere try to radiate in the infrared, but with a blanket that heat cannot escape anymore.
No matter if the blanket was laying around somewhere else for thousands of years, in that moment it gets warm.

This is of course a flawed **analogy**, the better one is the one of the greenhouse: Visible light can enter, providing heat, but cannot escape in the infrared, because the glass is intransparent to infrared.
The more $\rm CO\_2$ there is in the atmosphere, the more 'glass'. No matter if this glass was buried underground for ages, at this very moment it causes temperatures to rise enormously.  
Same story with why a car heats up into a death trap in summer, while the exterior of the car at the same moment doesn't.

Your friend (and probably other climate denialists) confuse the Earth's mass balance with its energy balance. One doesn't have much to do with the other.


---

### Answer by username_9 on 2019-05-03. Score: 1

Something else to consider: the amount of energy we get from the sun is slowly increasing over the billions of years as the sun goes through its lifecycle, so when you go back to ancient atmospheres and find what we would consider very high concentrations of GHG like CO2, it was necessary at that time to keep the planet warm. You can't simply look at the atmosphere from half a billion years ago and compare it with the present without considering the solar output.


---

