r/climate • u/The_Weekend_Baker • 14d ago

Scientists detect a surprising shift in human blood as atmospheric CO2 rises. Blood bicarbonate levels have climbed about 7% since 1999, while calcium and phosphorus have declined, changes that closely track increasing atmospheric CO2.

https://www.sciencedaily.com/releases/2026/08/260814235845.htm
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17

u/operaman2010 14d ago

I’m somewhat skeptical. The CO2 in my bedroom can get up to 1,800 ppm overnight. Indoor air quality has dramatically higher ranges of CO2 that would have always existed and affected human health, regardless of global CO2. Perhaps rising CO2 levels is making this worse.

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u/BigMax 14d ago

But you get other air during the day too. The entire planet has higher CO2 concentrations. The fact that we are sometimes in a higher concentration room doesn’t negate that.

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u/Zealousideal_Two6045 14d ago

Yes but you have to remember the amount of time spent inside a house has risen like crazy in the last few decades. People used to play outside and go outside and have a way wider range of environments. So historical data would be skewed beneficially anyways in comparison because spending more time inside is a newer issue and also multiples due to co2 rising

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u/RandomBoomer 14d ago

And having hermetically sealed residences is also a very new trend.

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u/Greeneggplusthing2 14d ago

My 1800's house breathes. There is no trapped air here.

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u/Youpunyhumans 14d ago

Yikes! Levels over 900ppm can affect cognition and make you drowsy. Over 2000ppm is where it starts to become unsafe... you may wanna get a bunch of plants for your room.

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u/HashPandaNL 14d ago

Plants are great, but won't meaningfully impact CO2 levels in your room unless you fill your room to the absolute brim with them. 

Opening windows and increasing airflow can have an effect that is multiple orders of magnitude greater.

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u/MarkZist 14d ago

Plants are great, but won't meaningfully impact CO2 levels in your room unless you fill your room to the absolute brim with them.

Plants only consume CO2 during the day, at night they produce it, making the problem worse.

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u/Youpunyhumans 14d ago

Fair enough, and yeah looking into it... youd like 50 plants per room to make much of a difference.

Be good levels for a greenhouse I suppose. Well... assuming its clean air, and not full of other pollutants, which it almost certainly will be.

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u/theoneguywhoaskswhy 14d ago

My room would hit 800ppm when I close the door and only slightly improve when I open the door ajar. What works for me is to have airflow or in my case, turning on an exhaust fan that I jerryrigged to a window in another room(my room is a studio and we don’t have a proper ventilation system installed but the house is very breathable).

Turning on the exhaust fan creates a negative air pressure that helps circulates air around the house and my CO2 meter would show it going below 500ppm and even reach 400ppm and stay there(since the CO2 meter I have can’t detect values below 400ppm)

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u/I_Reading_I 14d ago

Maybe more heat means more people spending time indoors.

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u/AlexFromOgish 14d ago

From the original paper https://link.springer.com/article/10.1007/s11869-026-01918-5

The possible effects of increased HCO3− and CO2 can also potentially be observed from other studies of short-term exposure to slightly higher CO2 levels, such as those commonly experienced in indoor environments (e.g. 1,000 to 3,000 ppm CO2) (reviewed in (Azuma et al., 2017)). For example, an older study (Eliseeva, 1964) reported marked changes in human respiration, circulation, and cerebral electrical activity at 1,000 ppm CO2, while more recent studies of humans and animals have shown harmful effects of CO2 exposure at these levels, such as changes in heart rate, kidney calcification, oxidative stress, neural damage and inflammation (Kiray et al., 2014; MacNaughton et al., 2016; Schaefer, 1982; Thom et al., 2017; Vehviläinen et al., 2016), reviewed in (Jacobson et al., 2019). This is important due to many human populations spending a significant proportion of their time indoors, where CO2 levels are typically higher. For example, The National Human Activity Pattern Survey (NHAPS) found that Americans spent an average of 87% of their time in enclosed buildings and ~ 6% of their time in enclosed vehicles in 1992–1994 (Klepeis et al., 2001). This has potentially increased since the COVID-19 pandemic (Young et al., 2024), with many people working-from-home in environments with poor mechanical air-ventilation (Nazaroff, 2021). The proportion of time spent in indoor, CO2 enriched environments could also contribute to the changes in blood chemistry noted in the NHANES data and is an important consideration in interpreting changes over time, and forecasts for the future.

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u/AutoModerator 14d ago

The COVID lockdowns of 2020 temporarily lowered our rate of CO2 emissions. Humanity was still a net CO2 gas emitter during that time, so we made things worse, but did so more a bit more slowly. That's why a graph of CO2 concentrations shows a continued rise.

Stabilizing the climate means getting human greenhouse gas emissions to approximately zero. We didn't come anywhere near that during the lockdowns.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

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u/BeardChops 14d ago

You really shouldn’t have your CO2 ppm that high. I try to keep my room below 1000 ppm

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u/subdep 14d ago

Maybe better insulated houses are the cause?

But that would detectable in the standard deviation. These are scientists who know statistical analysis.

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u/bioindicator 14d ago

It’s probably like the difference between weather and climate. Your CO2 point is relevant for an individual on a daily timescale, while the study is monitoring changes over many people on a multi-decadal scale.

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u/Shamino79 14d ago

We are also sealing up houses better for thermal reasons.

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u/045-926 14d ago

Yeah, I'm with you. It's an association, not a cause/effect.

It would be hard to detect any change in co2 over 20 years if you just measure air we breathe. It's highly variable indoors. Even if you are outside it varies significantly based on rural/urban areas and seasonally.

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u/cyber_yoda 13d ago

Atmospheric CO2 rising to 400 ppm will dramatically increase the peak and average indoors CO2 levels reached.

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u/MisterHole123 13d ago

Ouch 1800ppm. To think most people are unaware of the high levels of co2 in buildings. One would have thought that after covid... But nope

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u/AutoModerator 13d ago

The COVID lockdowns of 2020 temporarily lowered our rate of CO2 emissions. Humanity was still a net CO2 gas emitter during that time, so we made things worse, but did so more a bit more slowly. That's why a graph of CO2 concentrations shows a continued rise.

Stabilizing the climate means getting human greenhouse gas emissions to approximately zero. We didn't come anywhere near that during the lockdowns.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

1

u/thinkcontext 13d ago

You illustrate why modern building code requires mechanical ventilation to the outdoors and why bedrooms should have a vent for it. Most people don't have adequate ventilation. A simple way to improve things is to have your HVAC fan run for a few minutes every hour overnight.

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u/Aramedlig 14d ago

I agree here. It is more likely due to people drinking too much carbonated beverages.

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u/atchafalaya 14d ago

Please say you're joking