SAEDNEWS: A study of over 20 years of U.S. health data links rising atmospheric CO₂ to increased blood bicarbonate and lower calcium and phosphorus levels.
According to Saednews, A new study suggests that rising levels of carbon dioxide (CO2) in the atmosphere may already be causing gradual changes in human blood chemistry.
Published in Air Quality, Atmosphere and Health, the research analyzed blood-test data from approximately 7,000 participants in the US National Health and Nutrition Examination Survey collected between 1999 and 2020.
Researchers from The Kids Research Institute Australia, Curtin University and the Australian National University found that these changes occurred as atmospheric CO2 levels rose from around 369 parts per million (ppm) in 2000 to more than 420 ppm today.
The study found gradual shifts in several blood markers, including bicarbonate, calcium and phosphorus. Bicarbonate is essential for maintaining the body's acid-base balance, and the body may retain more of it as CO2 levels increase to help keep blood pH stable.
Associate Professor Alexander Larcombe, one of the study's authors, said the findings could indicate that the human body is already responding to changes in the composition of the atmosphere.
“What we’re seeing is a gradual shift in blood chemistry that mirrors the rise in atmospheric carbon dioxide, which is driving climate change,” Larcombe said.
Researchers warned that maintaining this adjustment over long periods could potentially have physiological consequences. Their modeling suggests that if current trends continue, average bicarbonate levels could approach the upper limit of today's accepted healthy range within the next 50 years. Calcium and phosphorus levels could also move toward the lower end of their healthy ranges later this century.
The findings may be particularly important for children and teenagers, whose bodies are still developing and who are likely to experience longer lifetime exposure to elevated atmospheric CO2 levels.
During most of human evolution, atmospheric CO2 concentrations were estimated at approximately 280 to 300 ppm. Over the past decade, however, levels have increased by an average of about 2.6 ppm per year. In 2024 alone, atmospheric CO2 rose by 3.5 ppm.
Dr Phil Bierwirth, a retired environmental geoscientist affiliated with the Australian National University, emphasized that the study does not prove that rising atmospheric CO2 directly causes the observed changes in blood chemistry.
However, he said the consistency of the findings across a large population deserves further attention.
The researchers believe that rising atmospheric CO2 could represent an additional climate-related health concern alongside more established risks such as heatwaves, extreme weather and sea-level rise.
They stressed that the findings do not mean people will suddenly become ill after atmospheric CO2 reaches a particular level. Instead, the research points to the possibility of slow, population-wide physiological changes that should be monitored over time.
The team recommended tracking atmospheric composition alongside biological markers in large populations to better understand how gradual environmental changes may affect human health over decades.
According to the researchers, reducing CO2 emissions remains essential not only for limiting global warming but potentially for protecting long-term human health as well.
