Fire Starting Question

[Britney7]

Hello I have a theoretical question. I’m writing a paper and I’m dealing with a hypothetical scenario. Let’s say that the global oxygen level in the air dipped to 10% worldwide. I would assume that this would be enough to impair normal biological function for most humans. Now in this given scenario, I would like to know a few things. Firstly even though regular fires would be unable to start, would smouldering fires continue to burn? And would the glowing light from the smouldering embers be visible to people? Secondly I would like to know if a person living in this environment would be able to briefly start a fire by blowing on the embers or a material that could be ignited. Thank you, any help is appreciated. 

[Phi for All]

I don't think 10% is enough to keep mental functions operating, so whether you could understand what you were seeing is questionable. It's also doubtful you would have the strength to blow on anything, much less drag yourself to where the embers are. It wouldn't take much effort to exhaust you.

[Britney7]

Thanks for your response. I know that function would be impaired a lot but I was wondering more about the mechanics of oxygen in relation to smouldering fire. Could wood smoulder at that temperature and if it would be visible. In regards to the second question, it would be more of a what if. If you mustered enough strength in the minute or two into the ordeal would the oxygen from blowing  be enough to help get a fire going even in a low oxygen environment?

[Phi for All]

2 hours ago, Britney7 said:

Could wood smoulder at that temperature and if it would be visible.

https://www.sciencedirect.com/science/article/abs/pii/S0010218021003345

Quote

Combining the computational and experimental results, we showed that particleboard undergoes only pyrolysis in oxygen concentrations below 4%, smouldering between 4 and 15%, and flaming above 15% at a heat flux of 30 kW/m2. 

 

2 hours ago, Britney7 said:

In regards to the second question, it would be more of a what if. If you mustered enough strength in the minute or two into the ordeal would the oxygen from blowing  be enough to help get a fire going even in a low oxygen environment?

The missing bit of information is what replaced the missing bit of oxygen in the atmosphere. If the 10% oxygen was replaced by CO2, it could be a huge problem. Also, the study I linked to above states that you won't get flames until you reach 15%, at least with particleboard. I'm not sure blowing on it will increase the O2 enough.

[studiot]

8 hours ago, Britney7 said:

Hello I have a theoretical question. I’m writing a paper and I’m dealing with a hypothetical scenario. Let’s say that the global oxygen level in the air dipped to 10% worldwide. I would assume that this would be enough to impair normal biological function for most humans. Now in this given scenario, I would like to know a few things. Firstly even though regular fires would be unable to start, would smouldering fires continue to burn? And would the glowing light from the smouldering embers be visible to people? Secondly I would like to know if a person living in this environment would be able to briefly start a fire by blowing on the embers or a material that could be ignited. Thank you, any help is appreciated. 

The short answer to your question is yes, some smouldering fires would continue to 'burn' unaided.

Perhaps you remember the Monkees song 'Pleasant Valley Sunday' ?

The line 'Charcoal burners everywhere' is relevant.

charcoal is what happens when you burn oxygen in reduced oxygen.

There is a nice chart for different fuels showinf the 'Limiting Oxygen Concentration' on Wikipedia

https://en.wikipedia.org/wiki/Limiting_oxygen_concentration

 

[John Cuthber]

Here's a start.

When George awoke, he felt better than he had for days.
The next thing that struck him was how quiet it was; the hospital had always been such a busy place.
Now, the only thing he could hear was the oxygen concentrator humming away by his bedside.
He remembered the doctor saying "With luck you might not need that tomorrow morning; you had a nasty brush with death , getting poisoned like that- but your lungs are healing well."

He also remembered his wife telling the doctor that he had been a professional racing cyclist in Rwanda. - the jokes about why anyone would choose it and the answers; not much competition, and the natural "altitude training" you get from a country that starts at about 950 metres above sea level, and only goes up.
The doctor asked if his genetics had helped.
He wasn't sure if the guy know that his dad was from Bhutan and his mother Peruvian.

He knew that without those lucky strikes, the chlorine leak at the swimming pool would have killed him, like it did all others there.

The next thing he noticed was two flickering lights in his darkened hospital room.
One was a "low oxygen" warning on the machine and the other was more threatening...


 

Edited August 12, 2023 by John Cuthber

[studiot]

23 minutes ago, John Cuthber said:

Here's a start.

I thought perhaps it was for a story.

 

+1

[Chhavi421]

In response to your hypothetical question, if the level of oxygen in the air worldwide were to dip to 10% it could be expected that most humans would face serious impaired biological function.

With regard to the fire scenario, it is likely that smouldering fires would still be able to continue to burn; however the same could not be said of regular fires. Furthermore, the smoulder light would still be visible as light emitted by the embers is unaffected by the low oxygen levels.

It is possible for a person in such an environment to briefly start a fire, providing they can access either materials or embers that would enable them to ignite a larger flame to get the fire going.