Why is the CO2 problem considered only in the context of climate?

[Line_112]

TL;DR Summary

When they write about the harm of carbon dioxide, they almost always touch only on its impact on the climate. However, I have read that this gas is also harmful to humans.

The CO2 level of 600 ppm is already compared to the effect of a stuffy room. At high concentrations, a feeling of suffocation occurs, as well as headaches and even an increase in intracranial pressure. I have also read that this gas slows down mental activity and reduces the level of motivation, as well as activity. Ventilating rooms with an increase in its concentration in the atmosphere will become increasingly difficult. And the increase in photosynthesis is accompanied by a decrease in the content of useful microelements and protein in plant biomass. As a result, among other things, the efficiency of animal husbandry decreases.

The combination of these effects with climate change is especially negative, when heat and stuffiness will also be accompanied by a feeling of suffocation.

It seems to me that they should also write a lot about this, and then politicians and ordinary people will have more motivation to reduce emissions.

 

[berkeman]

I have read

Please always post links to such reading when posting in the technical PF forums. Thanks.

The CO2 level of 600 ppm is already compared to the effect of a stuffy room. At high concentrations, a feeling of suffocation occurs, as well as headaches and even an increase in intracranial pressure.

Keep in mind that $CO_2$ is denser than air, so it usually sinks to the floor in rooms that do not have good ventilation [1]. That is one reason why having an excess of $CO_2$ in a room is often not a big issue for respiration. I've worked in electronics labs for decades where we use liquid $CO_2$ for cooling in our test ovens, and we've never had an issue with accumulation to the point where it interfered with our respiration.

[1] https://en.wikipedia.org/wiki/Carbon_dioxide

 

[Baluncore]

Climate change gets the attention. Higher CO₂ in the atmosphere has many effects, apart from climate change. The problem is, that bringing in a wider range of topics, makes the discussion more complex, and confusing, to the average viewer.

 

[Hornbein]

CO2 when dissolved in water forms carbonic acid which acidifies things. I heard concern about this way back in the 1960's. My Dad was worried about it. If it gets bad enough it will kill everything in the lakes and ocean. Acid rain wouldn't be much good for plants either. That's why coming up with some scheme to block the sunlight while letting CO2 continue to climb is a bad idea.

I once got a skin condition from drinking too much carbonated water. It was pretty unpleasant. Fortunately I was able to guess the cause and stop doing that. It cleared up in a few days.

 

[DaveC426913]

I once got a skin condition from drinking too much carbonated water. It was pretty unpleasant.

I am curious what the condition was.
I drink an above average amount of carbonated bevy.

 

[berkeman]

I am curious what the condition was.
I drink an above average amount of carbonated bevy.

Sugary carbonated beverages or non-sugar selzer? From my Google search it makes a difference.

 

[DaveC426913]

Sugary carbonated beverages or non-sugar selzer? From my Google search it makes a difference.

Sugar-free, caffeine-free diet cola. At least 1600mL/day.

 

[berkeman]

I am curious what the condition was.
I drink an above average amount of carbonated bevy.

Donning my Googles () you should be fine:

https://www.google.com/search?clien...ition+from+drinking+too+much+carbonated+water

 

[Hornbein]

Then there was the lunch I had at a Chinese restaurant. An hour later my torso felt like and appeared to have fifty mosquito stings. It didn't last long though. I never went back there. Must have been the MSG.

 

[fresh_42]

Sugar-free, caffeine-free diet cola. At least 1600mL/day.

I drink only carbonated breweries: beer, and water, sometimes soft drinks. I never had any problems with any of them.

 

[russ_watters]

The CO2 level of 600 ppm is already compared to the effect of a stuffy room. At high concentrations, a feeling of suffocation occurs, as well as headaches and even an increase in intracranial pressure. I have also read that this gas slows down mental activity and reduces the level of motivation, as well as activity. Ventilating rooms with an increase in its concentration in the atmosphere will become increasingly difficult.

Yeah, please post sources, because as an HVAC engineer, I'm reasonably certain that isn't true (while I note you only listed a concentration with the first one). The lowest I've ever heard of any impact is thin/anecdotal at 2,000 ppm and the industry standard maximum for indoors is 1,000 ppm.

[Late edit] And note, the 1,000 ppm isn't based on CO2 exposure health concerns, it's because CO2 is used as a generic proxy for indoor air quality.

 

[Line_112]

Please always post links to such reading when posting in the technical PF forums. Thanks.


Keep in mind that $CO_2$ is denser than air, so it usually sinks to the floor in rooms that do not have good ventilation [1]. That is one reason why having an excess of $CO_2$ in a room is often not a big issue for respiration. I've worked in electronics labs for decades where we use liquid $CO_2$ for cooling in our test ovens, and we've never had an issue with accumulation to the point where it interfered with our respiration.

[1] https://en.wikipedia.org/wiki/Carbon_dioxide

When we sleep, we are close to the floor, which means the quality of sleep may deteriorate.

 

[Line_112]

Yeah, please post sources, because as an HVAC engineer, I'm reasonably certain that isn't true (while I note you only listed a concentration with the first one). The lowest I've ever heard of any impact is thin/anecdotal at 2,000 ppm and the industry standard maximum for indoors is 1,000 ppm.

It could have been a frivolous source. I just remembered everything I had read about it before. Of course, I don't remember the sources anymore.

 

[russ_watters]

Ok, well, sources are important to being able to respond meaningfully to a specific claim, which is why we insist on them as a matter of policy. In general, you should learn to do some of your own research and in particular, vet your sources. But I'll give a summary since this is my area:

Since CO2 is an industrial gas used in a variety of applications, it is a common hazard in industrial workplaces. My area is HVAC for pharmacuticals, and it is common in a lot of applications there. In the US, the Occupational Health and Safety Administration (OSHA) dictates standards regarding safe exposure limits in the workplace:

https://www.osha.gov/chemicaldata/183
https://www.osha.gov/publications/hib19960605

The current OSHA standard 8-hour (workday length) average exposure limit is 5,000 ppm.

Just in case you didn't see my edit in the prior post, I cited the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) limit of 1,000 ppm. It is important to recognize that CO2 is just used as a convenient proxy for ventilation effectiveness and indoor air quality (originally/before AC it was intended as a proxy to determine ventilation to dilute body odor), so that 1,000 ppm limit does not imply a health hazard from CO2 itself at that level:

https://www.ashrae.org/file library/about/position documents/pd_indoorcarbondioxide_2022.pdf

That article is a very good overview of the history and research regarding CO2 exposure indoors, and includes discussion of the low-level impacts -- or rather, the poorly substantiated research on it. The general conclusion is that for lower levels the cognitive impact becomes so minimal it is impossible to tell at what level cognitive impact starts. A notable excerpt:

"Indoor concentrations of CO2 greater than 1000 ppmv have been associated with increases
in self-reported, nonspecific symptoms commonly referred to as sick building syndrome (SBS)
symptoms. However, these observations were not controlled for other contaminants or environmental parameters; therefore, elevated CO2 concentrations likely served as indicators of
inadequate ventilation that increased the concentrations of all contaminants with indoor
sources. More recently, several groups have explored the cognitive effects of short-term exposure (2 to 8 h) to pure CO2 at concentrations between 600 and 5000 ppmv. Some of these studies demonstrated concentration-dependent impairment, an indicator of a causal effect, but
other studies did not show any effects on cognition. These inconsistencies require further investigation, including study of the mechanisms involved. This research is a priority due to the ubiquity of indoor concentrations of CO2 in excess of 1000 ppmv."

Also, a historical and movie buff note: The Apollo 13 astronauts were breathing about 19,600 ppm (14.9 mm hg) prior to fixing their CO2 scrubbers. Acute health effects are well established at that level after several hours of exposure.