Scientists detect a surprising shift in human blood as CO2 rises

Recent research reveals a potential link between rising atmospheric carbon dioxide levels and alterations in human blood chemistry. A study published in Air Quality, Atmosphere and Health found persistent changes in blood markers that aligned with the increase in atmospheric CO2 over a 20-year period. The Kids Research Institute Australia, Curtin University, and The Australian National University analyzed data from the U.S. National Health and Nutrition Examination Survey, examining the blood test results of around 7,000 individuals at two-year intervals between 1999 and 2020.

Scientists discovered that average serum bicarbonate levels, which are closely tied to CO2 in the body, rose by approximately 7 percent during this time. At the same time, levels of calcium and phosphorus decreased. Associate Professor Alexander Larcombe, the study's author, noted that the findings suggest the body may be adjusting to the changing atmospheric composition.

Bicarbonate plays a crucial role in maintaining the body's acid-base balance. As CO2 increases, the body can retain more bicarbonate to stabilize blood pH. However, if current trends persist, modeling predicts that average bicarbonate levels could reach the upper limit of the healthy range within 50 years. Similarly, calcium and phosphorus levels could drop to the lower end of their healthy range later this century.

While the study does not establish a direct cause-and-effect relationship, researchers emphasize that the consistency of these changes across a large population warrants attention. They caution that rising atmospheric CO2, a phenomenon never experienced by humans before, may have physiological effects on the body. The researchers argue that monitoring rising CO2 levels alongside biological markers in populations should be considered as part of future climate change policy, alongside its well-documented environmental consequences.