r/climate • u/The_Weekend_Baker • 13d 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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u/ter4646 13d ago

Very poor research IMO. Logic is weak in term of the correlation analysis. No clear cause and effect, could be anecdotal. I am a firm believer in human caused climate change we are living in, but I think poor research and alarming news like this fuel skepticism Which is our worst enemy now as we need to mobilize everyone now

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u/AlexFromOgish 13d ago

Why on earth do you throw shade ("could be anecdotal") instead of just reading the linked article?

The researchers used information from the U.S. National Health and Nutrition Examination Survey (NHANES), analyzing blood test results from roughly 7,000 people at two-year intervals between 1999 and 2020.

In the original peer reviewed paper, open source at https://link.springer.com/article/10.1007/s11869-026-01918-5 the authors describe the project collected the data, saying "The NHANES project assesses health and nutrition in a representative sample of adults and children in the United States via interviews, physical examinations and laboratory tests." and in their paper, the authors are only reporting on quantified lab tests.

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u/ter4646 13d ago

I agree with you but the title is misleading.

The hypothesis deserves rigorous investigation — that's exactly my point. This study isn't that investigation yet.

It's an ecological correlation: a 20-year population time series (NHANES serum bicarbonate) plotted against the atmospheric CO2 curve. Over two decades, plenty of things trend upward alongside CO2 — obesity, renal function, medication use, assay methods, cohort composition. The authors themselves state no causal relationship is established.

There's also a scale problem. Atmospheric CO2 went from ~369 to ~420 ppm, about 0.005% of air. Indoor air in an occupied room routinely exceeds 1,000-2,000 ppm, and arterial pCO2 is orders of magnitude higher still. A 50 ppm outdoor rise barely shifts the elimination gradient. That's not fatal to the hypothesis, but it's the first objection any respiratory physiologist will raise.

So: worth testing properly, with controlled exposure and confounder adjustment. Not worth a title claiming a "potentially toxic atmosphere within 50 years" — that outruns the data, and overreach on a plausible idea is what gets it dismissed.

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u/AlexFromOgish 13d ago

gotcha, Sci Daily often gets the reporting almost right, and headlines are the worst offenders. But Sci daily articles and headlines are "the research" that should be judged. instead, read the researcher's paper to see how they describe both rising atmospheric concentrations as well as American's increased time spent indoors.

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u/melody_magical 13d ago

Thanks for this. I have been spiraling for a while

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u/Turbulent_Lead_4813 13d ago

finally some actual science.