Scientists analyzing more than two decades of U.S. health data have identified a surprising shift in human blood chemistry that appears to track rising atmospheric CO₂ levels. Researchers found that average blood bicarbonate levels increased by about 7% between 1999 and 2020, while calcium and phosphorus levels declined. Bicarbonate plays a key role in maintaining the body’s acid–base balance and is closely linked to CO₂ levels in the body. The researchers note that the study does not establish a direct cause-and-effect relationship. However, the long-term consistency of these changes raises important questions about how continued increases in atmospheric CO₂ could affect human physiology, particularly in younger generations who may experience greater lifetime exposure. The findings suggest that climate change may have implications extending beyond the environment, highlighting the importance of further research into the long-term effects of rising CO₂ on human health.
