<p>There is no such thing as a single "natural" level of <span class="math-container">$CO_2$</span>: In Earth's history, there have been levels much higher and much lower than currently, and they are all natural.</p>

<p>What we should consider instead is what levels of <span class="math-container">$CO_2$</span> are compatible with the mild and stable climate that humanity has enjoyed for the last few millennia, or conversely, which levels will upset the climatic equilibrium and send Earth into a completely new climatic regime.</p>

<p>The means to measure atmospheric <span class="math-container">$CO_2$</span> concentrations were invented during the industrial revolution, so we don't have direct records before that. However, we can reconstruct past <span class="math-container">$CO_2$</span> concentrations using proxies such as the analysis of air bubbles trapped deep within the ice in Antarctica.</p>

<p>Ice cores were drilled up to ~600 meters deep between 1987 to 1993 at <a href="https://en.wikipedia.org/wiki/Law_Dome" rel="nofollow noreferrer">Law Dome</a> (Antarctica), allowing the reconstruction of <span class="math-container">$CO_2$</span> concentrations from the last millennium, and it looks like this:</p>

<p><a href="https://i.sstatic.net/jUawO.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/jUawO.png" alt="enter image description here"></a></p>

<p>Where the darker blue at the end corresponds to the direct instrumental record (<a href="https://www.co2.earth/co2-ice-core-data" rel="nofollow noreferrer">source</a>).</p>

<p>Later, another ice core from Vostok station in Antarctica was drilled to a depth of more than 3.6 km, allowing the reconstruction of atmospheric <span class="math-container">$CO_2$</span> concentration during the last 400,000 years, and it looks like this:</p>

<p><a href="https://i.sstatic.net/7ayCs.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/7ayCs.png" alt="enter image description here"></a></p>

<p>(Figure <a href="https://www.co2.earth/co2-ice-core-data" rel="nofollow noreferrer">source</a>)</p>

<p>The data from Law Dome and that of modern records at Mauna Loa, Hawaii are also displayed on the end for comparison.</p>

<p>More ice cores have been drilled after Vostok, and all of them tell more or less the same story.</p>

<p>So we know that atmospheric <span class="math-container">$CO_2$</span> concentrations now are much higher than at any other time since we invented agriculture. And the people that think they know how the atmosphere works run models and say that current levels will significantly upset the climate as we know it. On the other hand, the people who don't know how the atmosphere works (like me), should just stop producing so much <span class="math-container">$CO_2$</span>, because we don't ourselves know what the effects could be, and at the same time, we rely on the climate to stay nice and stable to keep your flourishing society alive.</p>

<p>To address the last bit of the question, to transform 1 PPM by volume of atmospheric <span class="math-container">$CO_2$</span> into a GigaTon of Carbon you <a href="https://cdiac.ess-dive.lbl.gov/pns/convert.html#3." rel="nofollow noreferrer">just have to multiply by  2.13</a>. So the pre-industrial base level during the last millennia of 280 PPM is equivalent to ~596 GtC or 2,187 Gt of <span class="math-container">$CO_2$</span> (multiply again by 44/12, the ratio of <span class="math-container">$CO_2$</span> mass to C mass).</p>

CC BY-SA 4.0
2019-02-14T23:51:35.737Z
This graph looks suspiciously like a HOCKEY stick Camilo!
stormy
CC BY-SA 4.0
2019-02-15T03:25:53.723Z
@stormy And what that is supposed to mean? I don't get it.
Camilo Rada
CC BY-SA 4.0
2019-02-15T07:34:02.610Z
The famous 'hockey stick' graph Mr. Mann literally made up about CO2.
stormy
CC BY-SA 4.0
2019-02-15T21:53:02.183Z
The best source is John L. Casey plus 3 and 4 other scientists, their books are; Cold Sun, Dark Winter and the latest is Upheaval!  I can't believe such intelligent people on this site can be hoodwinked by the media and the popular 'stance'.  Scary.
stormy
CC BY-SA 4.0
2019-02-15T22:05:36.050Z
@stormy I'm a Chilean glaciologist that doesn't work for any government. The data I showed here have been extracted by colleagues from Antarctic ice cores, I know some of them personally. Answers like the one you posted should be backed with references: big proofs for big claims.
As me, there thousands of scientist that devote all their time to questions like this and that have found outstanding evidence to show that most of what you said in your answer is wrong, as well as many of John Casey claims. If you rather believing that all of us are conspiring against you, there is nothing I can do.
Camilo Rada
CC BY-SA 4.0
2019-02-15T22:12:39.330Z
Forget me worrying about YOU GUYS conspiring against me!  Grins!  I am waiting for the day you GUYS are able to see whatever you believe and are standing upon is fast dissolving.  I know I am smart and very well educated but never imagined myself going up against such intelligent people, and why the heck would I DO that?  I very clearly see that what I am saying, at least 90 percent is correct.  I am looking around the room to see if anyone else understands what I am saying.  I try to stay out of your site but gee, people are asking questions of you and you are dismissing those ?? immediately.
stormy
CC BY-SA 4.0
2019-02-18T22:55:25.083Z
Have you read or seen a bit of Upheaval the book written by 4 scientists?  Or Cold Sun or Dark Winter?  I would love to hear your comments on some real stuff.  I thought that John L. Casey which to me was very very credible would be a great reference.  I added references, I always add references...no one likes them because they don't even look at them because they don't want their flimsy view of reality to be disturbed.  Sure would like to hear some real science that makes sense for global warming and guess what?  I have not FOUND any science to defend or support warming!
stormy
CC BY-SA 4.0
2019-02-18T23:51:12.713Z
@Camilorada...I've got to give you the name of this incredible geologist up here in the Pacific Northwest.  I just know you will love his lectures!  Free on the internet!  Even non geologists LOVE learning from him!  A real, black board teacher. He has nothing to do with warming, just geology!  The PNW is such an amazing, geologically vigorous area with a powerful historic past. Look up Nick Zentner from Central Washington University.  You will LOVE his lectures!  Another super duper dude for human biology is Robert Sapolsky of Stanford University!  Incredible FREE lectures!
stormy
CC BY-SA 4.0
2019-02-20T02:16:23.567Z
The question was pre industrial CO2 levels.  I answered that. We are just now coming out of the last ice age, seriously.  Cold sequestrates CO2.  Warmth releases CO2 from sequestration to be used by plants.  So whatever data we have on troposphere CO2 counts is only indicative of coming out of an ice age.  I have been going on about the lowest level of CO2 where all plants DIE.  150 ppm.  400 ppm is too close to this lower level! Are these numbers agreeable with you?  Name one John Casey claim that you think is wrong, please.  And how does .04 percent CO2 become a problem?  So tiny!
stormy
CC BY-SA 4.0
2019-02-20T02:26:37.943Z
And I have been taught that ice calving shows glaciers advancing, not retreating or melting, right?  Glaciation is an incredible science...Glaciers are powerful forces we humans are unable to understand within the short time we see stuff on this planet.  You will love Nick Zentner!  Stones that were transported hundreds of miles, not by water, but by being encased in ice that floats, melts and deposits the 2 story high boulder of granite on top of glacial loess...or basalt extruded from rifts not volcanoes...
stormy
CC BY-SA 4.0
2019-03-12T13:21:43.980Z
@CamiloRada this is an ongoing project right now https://www.beyondepica.eu/about/ it should provide good data about the last one and a half million years.
trond hansen
CC BY-SA 4.0
2019-02-09T01:29:07.963Z
2019-02-12T00:50:13.613Z
2019-02-12T00:50:13.613Z
Camilo Rada
<p>Are the levels of natural (before the industrial revolution) levels of CO2 and ppm known? Also as a related question, should the "natural" levels be considered before the industrial revolution or before the start of the deforestation 8000 years ago?</p>

CC BY-SA 4.0
2019-02-08T13:14:24.707Z
for the last 500000 years the CO2 level have been from 180-280 ppm we are at 410 ppm now i do not think this is safe.
trond hansen
CC BY-SA 4.0
2019-02-08T13:37:16.577Z
The absolute level is only one side of the coin, you also have to look at how fast the change happens, if the ecosphere as a whole can adapt to the changes
Erik
CC BY-SA 4.0
2019-02-20T03:01:05.557Z
400 ppm CO2 is truly too low.  CO2 in no way jose can possibly warm this planet!  Mars has 95% CO2 atmosphere and that percentage is not helping Mar's atmosphere to warm.  Yet Venus?  97% CO2...both planets lost the life and their oceans and the lighter gases got ripped off to be replaced by the CO2 that couldn't stay in sequestration because life and oceans were gone...thus almost 100 percent CO2.  On both planets, one cold and one hot.  Mankind is not MAKING more CO2 we are releasing CO2 from sequestration or storage a bit earlier. There is no global warming happening!!  We are in a GSM...
stormy
<climate-change><climate><paleoclimatology><co2><deforestation>
What are the ranges of natural (or pre-industrial era) levels of CO2 in the atmosphere in ppm and tons?
Pablo
# What are the ranges of natural (or pre-industrial era) levels of CO2 in the atmosphere in ppm and tons?

(Asked by: username_0 on 2019-02-08)

Are the levels of natural (before the industrial revolution) levels of CO2 and ppm known? Also as a related question, should the "natural" levels be considered before the industrial revolution or before the start of the deforestation 8000 years ago?

**Tags:** climate-change, climate, paleoclimatology, co2, deforestation

> **Comments:**
> **username_1**: for the last 500000 years the CO2 level have been from 180-280 ppm we are at 410 ppm now i do not think this is safe.  
> **username_2**: The absolute level is only one side of the coin, you also have to look at how fast the change happens, if the ecosphere as a whole can adapt to the changes  
> **username_3**: 400 ppm CO2 is truly too low.  CO2 in no way jose can possibly warm this planet!  Mars has 95% CO2 atmosphere and that percentage is not helping Mar's atmosphere to warm.  Yet Venus?  97% CO2...both planets lost the life and their oceans and the lighter gases got ripped off to be replaced by the CO2 that couldn't stay in sequestration because life and oceans were gone...thus almost 100 percent CO2.  On both planets, one cold and one hot.  Mankind is not MAKING more CO2 we are releasing CO2 from sequestration or storage a bit earlier. There is no global warming happening!!  We are in a GSM...  

---

## 1 answers

### Answer by username_4 on 2019-02-09. Score: 7 | Accepted answer

There is no such thing as a single "natural" level of $CO\_2$: In Earth's history, there have been levels much higher and much lower than currently, and they are all natural.

What we should consider instead is what levels of $CO\_2$ are compatible with the mild and stable climate that humanity has enjoyed for the last few millennia, or conversely, which levels will upset the climatic equilibrium and send Earth into a completely new climatic regime.

The means to measure atmospheric $CO\_2$ concentrations were invented during the industrial revolution, so we don't have direct records before that. However, we can reconstruct past $CO\_2$ concentrations using proxies such as the analysis of air bubbles trapped deep within the ice in Antarctica.

Ice cores were drilled up to ~600 meters deep between 1987 to 1993 at [Law Dome](https://en.wikipedia.org/wiki/Law_Dome) (Antarctica), allowing the reconstruction of $CO\_2$ concentrations from the last millennium, and it looks like this:

[![enter image description here](https://i.sstatic.net/jUawO.png)](https://i.sstatic.net/jUawO.png)

Where the darker blue at the end corresponds to the direct instrumental record ([source](https://www.co2.earth/co2-ice-core-data)).

Later, another ice core from Vostok station in Antarctica was drilled to a depth of more than 3.6 km, allowing the reconstruction of atmospheric $CO\_2$ concentration during the last 400,000 years, and it looks like this:

[![enter image description here](https://i.sstatic.net/7ayCs.png)](https://i.sstatic.net/7ayCs.png)

(Figure [source](https://www.co2.earth/co2-ice-core-data))

The data from Law Dome and that of modern records at Mauna Loa, Hawaii are also displayed on the end for comparison.

More ice cores have been drilled after Vostok, and all of them tell more or less the same story.

So we know that atmospheric $CO\_2$ concentrations now are much higher than at any other time since we invented agriculture. And the people that think they know how the atmosphere works run models and say that current levels will significantly upset the climate as we know it. On the other hand, the people who don't know how the atmosphere works (like me), should just stop producing so much $CO\_2$, because we don't ourselves know what the effects could be, and at the same time, we rely on the climate to stay nice and stable to keep your flourishing society alive.

To address the last bit of the question, to transform 1 PPM by volume of atmospheric $CO\_2$ into a GigaTon of Carbon you [just have to multiply by 2.13](https://cdiac.ess-dive.lbl.gov/pns/convert.html#3.). So the pre-industrial base level during the last millennia of 280 PPM is equivalent to ~596 GtC or 2,187 Gt of $CO\_2$ (multiply again by 44/12, the ratio of $CO\_2$ mass to C mass).

> **Comments:**
> **username_3**: This graph looks suspiciously like a HOCKEY stick username_4!  
> **username_4**: @username_3 And what that is supposed to mean? I don't get it.  
> **username_3**: The famous 'hockey stick' graph Mr. Mann literally made up about CO2.  
> **username_3**: The best source is John L. Casey plus 3 and 4 other scientists, their books are; Cold Sun, Dark Winter and the latest is Upheaval!  I can't believe such intelligent people on this site can be hoodwinked by the media and the popular 'stance'.  Scary.  
> **username_4**: @username_3 I'm a Chilean glaciologist that doesn't work for any government. The data I showed here have been extracted by colleagues from Antarctic ice cores, I know some of them personally. Answers like the one you posted should be backed with references: big proofs for big claims. As me, there thousands of scientist that devote all their time to questions like this and that have found outstanding evidence to show that most of what you said in your answer is wrong, as well as many of John Casey claims. If you rather believing that all of us are conspiring against you, there is nothing I can do.  
> **username_3**: Forget me worrying about YOU GUYS conspiring against me!  Grins!  I am waiting for the day you GUYS are able to see whatever you believe and are standing upon is fast dissolving.  I know I am smart and very well educated but never imagined myself going up against such intelligent people, and why the heck would I DO that?  I very clearly see that what I am saying, at least 90 percent is correct.  I am looking around the room to see if anyone else understands what I am saying.  I try to stay out of your site but gee, people are asking questions of you and you are dismissing those ?? immediately.  
> **username_3**: Have you read or seen a bit of Upheaval the book written by 4 scientists?  Or Cold Sun or Dark Winter?  I would love to hear your comments on some real stuff.  I thought that John L. Casey which to me was very very credible would be a great reference.  I added references, I always add references...no one likes them because they don't even look at them because they don't want their flimsy view of reality to be disturbed.  Sure would like to hear some real science that makes sense for global warming and guess what?  I have not FOUND any science to defend or support warming!  
> **username_3**: @Camilorada...I've got to give you the name of this incredible geologist up here in the Pacific Northwest.  I just know you will love his lectures!  Free on the internet!  Even non geologists LOVE learning from him!  A real, black board teacher. He has nothing to do with warming, just geology!  The PNW is such an amazing, geologically vigorous area with a powerful historic past. Look up Nick Zentner from Central Washington University.  You will LOVE his lectures!  Another super duper dude for human biology is Robert Sapolsky of Stanford University!  Incredible FREE lectures!  
> **username_3**: The question was pre industrial CO2 levels.  I answered that. We are just now coming out of the last ice age, seriously.  Cold sequestrates CO2.  Warmth releases CO2 from sequestration to be used by plants.  So whatever data we have on troposphere CO2 counts is only indicative of coming out of an ice age.  I have been going on about the lowest level of CO2 where all plants DIE.  150 ppm.  400 ppm is too close to this lower level! Are these numbers agreeable with you?  Name one John Casey claim that you think is wrong, please.  And how does .04 percent CO2 become a problem?  So tiny!  
> **username_3**: And I have been taught that ice calving shows glaciers advancing, not retreating or melting, right?  Glaciation is an incredible science...Glaciers are powerful forces we humans are unable to understand within the short time we see stuff on this planet.  You will love Nick Zentner!  Stones that were transported hundreds of miles, not by water, but by being encased in ice that floats, melts and deposits the 2 story high boulder of granite on top of glacial loess...or basalt extruded from rifts not volcanoes...  
> **username_1**: @username_4 this is an ongoing project right now https://www.beyondepica.eu/about/ it should provide good data about the last one and a half million years.  

---

