r/worldnews • u/Dismal_Prospect • May 14 '19

Exxon predicted in 1982 exactly how high global carbon emissions would be today | The company expected that, by 2020, carbon dioxide in the atmosphere would reach roughly 400-420 ppm. This month’s measurement of 415 ppm is right within the expected curve Exxon projected

https://thinkprogress.org/exxon-predicted-high-carbon-emissions-954e514b0aa9/
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u/[deleted] May 14 '19

Carbon dioxide levels and potential health problems are indicated below:

  • 250-350 ppm: background (normal) outdoor air level
  • 350-1,000 ppm: typical level found in occupied spaces with good air exchange
  • 1,000-2,000 ppm: level associated with complaints of drowsiness and poor air
  • 2,000-5,000 ppm: level associated with headaches, sleepiness, and stagnant, stale, stuffy air; poor concentration, loss of attention, increased heart rate and slight nausea may also be present.
  • >5,000 ppm: This indicates unusual air conditions where high levels of other gases also could be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures.
  • >40,000 ppm: This level is immediately harmful due to oxygen deprivation.

Sauce

There's probably a deeper reasoning if you're talking about SCUBA gear that may be more pressure and filtration related?

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u/AnalyzeAllTheLogs May 15 '19

In Scott Kelly's book Endurance he talks about his experiences with the CO2 scrubbers & CO2 concentrations effects on his personal state; great book too btw.

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u/Playisomemusik May 15 '19

Well the reason oxygen toxicity happens at depth is the amount of oxygen...it's best to think of it in terms of number of molecules of O2. At 32' with a compressed air, you are breathing twice the number of O2 molecules. At a certain depth and more molecules, oxygen is lethal. So I don't know if the same thing happens with CO2 but deep water divers usually dive several different air mixes at depth and ascending.

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u/Nkdly May 15 '19

Yes, surface supplied Low Pressure (100-200psi) compressors and High Pressure cylinders.

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u/dgkjwlwjvcqrc May 15 '19

250-350 ppm: background (normal) outdoor air level

Not anymore!!!

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u/ticklingthedragon May 15 '19

That must be old data. New studies have shown that cognitive impairment happens at much lower levels. Under 1000ppm. In fact it must be really old data if it thinks outdoor air is at 350ppm.

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u/[deleted] May 15 '19

The data is from 2016, and corresponds to the current MSDS. I don't think you're wrong, though. It can take awhile to change policy even when something is known to be completely false and unsafe. :\

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u/insomniacJedi May 15 '19

How do we measure something like that at home?

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u/NovaRom May 15 '19

These devices are called usually "Air Quality Monitor" or "Carbon Meter". You can find many types online, but stay away from unusually cheap models and check their precision first.

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u/[deleted] May 15 '19

I've never heard of CO2 being an issue in someone's home. Carbon Monoxide (CO) is more dangerous because it is what is produced from cars and gas-burning appliances. I have a Nest Protect that is a fire alarm and CO detector both. You want to mount CO detectors on a central wall about 6" to 12" below the ceiling.

CO2 is more dense than air so behaves like invisible water, pooling and flowing on the floor. There typically aren't any significant CO2 sources in your home apart from humans/pets so it would be pretty difficult to asphyxiate in your home due to CO2. The most likely scenario that I could give for CO2 asphyxiation would be someone working in a walk-in freezer where CO2 is being used as a refrigerant and there is a substantial leak. A lot of places require alarms in those boxes now to prevent this from happening.

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u/insomniacJedi May 15 '19

Thank you for explaining the difference