At what concentration does CO2 become toxic to humans?
Written by Dr. Darko Butina
Or, What is the difference between the engine that runs the human body and the combustion engine? None!
The molecule carbon dioxide (CO2), a trace gas in our atmosphere is just about reaching concentration of 400 parts per million or 0.04%, as measured at the Mauna Loa Observatory, better known as MLO. The current public view of CO2 is that of a villain causing practically everything that is wrong on our planet, from prostitution to tsunamis, from schizophrenia to earthquakes, from overheating to overcooling, from floods to droughts and so on.
Since well over one thousand peer reviewed papers say so, since all of the major television and newspapers outlets say so, since lot of national academies say so, surely it must be so? Surely, to accuse someone of mass murder and even genocide one would expect overwhelming evidence against the CO2 molecule; not by thousands of unreliable witnesses that never met or saw the murderer, but by the hard forensic data, in this case experimental data.
Since the standard definition of excellence in the climate sciences is ‘the less you know about CO2 and the calibrated thermometer, the more eminent scientist you are’, I will humbly present to you some basic facts about CO2 that all those “ignorant specialist” in respiratory mechanisms and carbon chemistry are using in their daily jobs of pushing the frontiers of science forward, not backwards.
This report is about toxicity of CO2 and I will answer that infamous $64,000 question, or the way that the things are going at the moment, $64 trillion question: At what concentration does CO2 become toxic to humans?
So let me start with the first question raised in the title of this report. You see, there is no difference between the engine that runs the human body and the combustion engine – they both run on the molecules that are based on the element called carbon with the symbol C, they both need the O2 molecules to break the fuel down to smaller chunks, or rather oxidise the fuel/food that is needed for the engine to run, and they both produce CO2 as a product of that oxidation process. For every single carbon that enters that engine (human body or combustion engine) one molecule of CO2 comes out.
Let us now turn to the medical sciences and our knowledge of the respiratory mechanism that is the key to our survival. For a long time scientists working in the field of human physiology have wandered why evolutionary forces made humans breathe out and assign the function of breathing in and out to the brain?Whether you are awake or asleep, every breath in is followed by the breath out – why is that?
We could easily understand breathing in – the human body cannot function without oxygen and therefore we should be OK by just breathing in. The answer became obvious once we realised that all life is based on the carbon atom with the molecules of DNA and proteins being the two main engines of that life. Since everything that supports life is based on carbon, it follows that the major fuel which runs the human engine needs to be based on carbon. For clarity, whether you eat meat or are vegetarian, you are consuming carbon! And then the knowledge of chemistry comes in – oxygen function is to ‘oxidise’ and since all the food is based on carbon, the result is CO2: C + O2 = CO2. It therefore follows that inside your body lots of CO2 has been produced as a by-product which needs to be taken out of the body – hence breathing out. As any textbook on respiration will tell you:
“The primary function of the lungs is to obtain oxygen for use by the body’s cells and eliminate the carbon dioxide that cells produce”.
The figure at the top of the page below shows the general principle of the exchanges of different gases that occur between the lungs and the blood stream:
Let me now bring in Dalton and the gas law named after him which is formulated in the following way:
p = p1 + p2 + p3 + …
where p is the total or measured pressure and p1, p2, … are the partial pressures of the individual gases.
For air, an appropriate form of Dalton’s law would be:
p(air) = p(N2) + p(O2) + p(CO2) + …
Let me slightly digress here and explain to non-scientists what the scientific laws are about. Unlike any law in everyday life which is formulated and defined by the committee of experts and politicians ( i.e. criminal law, and varies from one country to another country), the scientific laws are ‘extracted’ from the experimental data and the observations and then formulated by scientists. In case of Dalton, he made those observations back in 1800 but he had nothing to do with them being called after him, since it took another hundred years of observations by hundreds of other scientists – all observing the same thing for those observations to become scientific law. All the scientific laws have one thing in common – there is NOT a single observation in the published literature that fails the scientific law, because if there is one that fails it and it can be reproduced then the law is no longer a law and it is withdrawn from our knowledge database.
In the last 3 years, since I began trying to understand the mystic ways that the climate community is conducting their science, I came up with a very simple way to compare their climate science with real science – real science works on the principle that the science laws are absolute, that the physico-chemical properties of molecules are absolute and that the only way to measure the temperature of molecules is by using a calibrated thermometer. Meanwhile, it appears, the climate sciences stay away from all approved instruments as if they are infected by plague. They ignore scientific laws and use bits of (or none at all) of the physico-chemical properties of molecules, depending what the outcome of a particular computational simulation is needed. And they definitely do NOT measure things since the instrumental data has this habit of falsifying everything that their computers are producing.
But, back to the real science. In medical sciences 1 atmosphere, i.e. the pressure of the air at the sea level is expressed as 760 millimetres of mercury, 760 mm Hg. So, if we assume that the air consist of 78% N2, 21% of O2 and 0.04% of CO2 then each of the three molecules exerts the following pressure:
N2: (78/100)*760 = 593 mm Hg
O2: (21/100)*760 = 160 mm Hg
CO2: (0.04/100)*760 = 0.3 mm Hg
Now we need to make connection between the partial pressure of CO2 in the air and in the blood, before breathing in and after breathing out. For the gas molecule to cross from the lungs to the blood it needs to have the higher partial pressure in the lungs than in the blood, and obviously, the opposite is true – if the partial pressure of the gas molecule is higher in the blood than in the lungs, it will cross from the blood to the lungs. When it comes to CO2, its concentration in the blood, after the blood has collected all the CO2 generated by the bio-chemical process keeping the cells alive reaches the pressure of 45 mm Hg, while the pressure inside the lungs after we breathe in the air is 0.3 mm Hg.
Therefore, as long as the partial pressure of CO2 in the air that we breathe in is less than 45 mmHg, the human body will be able to clear out the cell-produced CO2. By the way, when people suffer serious brain damage which affects breathing, the function of those machines that maintain the life is to bring in the oxygen and make sure that all the CO2 is cleared from the blood stream.
The number to watch for is 45 mm Hg of CO2 in the air, or 6% or 60,000 PPM – that is the concentration of CO2 that needs to be reached for the humankind to become extinct. If my math is serving me right, if we divide 60,000 PPM with 400 PPM we get the ‘kill factor’ for CO2: 150.
In other words, the concentration of CO2 needs to increase 150-fold for the CO2 to become toxic.
Bearing in mind that all those mathematicians and paleo-something scientists do not have a clue about the real capacity of the CO2 sinks, like the water and the biomass (more about it in the next report) I reckon that we are perfectly safe for a long, long time and should celebrate CO2 as a gas of life. If it was not for CO2, we would not be discussing it today.
The reports to come:
How does the CO2 molecule travel from LA to MLO which is over 4000 km away and at altitude of 4km?
How can we survive the Christmas meal in a deadly atmosphere of the CO2 concentrations reaching massive 3000 PPM?
Did you know that every time you cut the grass in your garden you generate over 10,000 PPM of CO2!!!
Stay tuned. More from Dr. Butina at his blog http://l4patterns.com/