Scientists detect a surprising shift in human blood as CO2 rises

Scientists have discovered unexpected alterations in human blood chemistry as carbon dioxide levels in the atmosphere continue to rise. This new research, published in Air Quality, Atmosphere and Health, suggests that rising atmospheric CO2 may be influencing human biology and could potentially impact future generations. In a study conducted over two decades, researchers analyzed data from the U.S. National Health and Nutrition Examination Survey (NHANES), focusing on blood test results from approximately 7,000 individuals tested every two years between 1999 and 2020.

They found that average serum bicarbonate levels have increased by around 7 percent, while calcium and phosphorus levels have decreased over the same period. Bicarbonate plays a crucial role in regulating the body's acid-base balance, and the researchers' findings indicate that the body might already be adjusting to the changing atmospheric composition.

If current trends persist, average bicarbonate levels could reach the upper limits of the healthy range within the next 50 years. Dr. Phil Bierwirth, a retired environmental geoscientist, noted that while the study does not establish a direct cause-and-effect relationship, the consistency of the observed changes across a large population warrants further attention.

The researchers emphasize that rising atmospheric CO2 could be considered a unique climate-related risk, distinct from more familiar threats such as heatwaves and sea-level rise. They suggest that monitoring CO2 levels alongside biological markers could help assess the long-term effects on human health as part of future climate change policy.