Scientists are raising new concerns about the health impacts of climate change, warning that increasing levels of atmospheric carbon dioxide could gradually weaken human bones. A recent study published in the Air Quality, Atmosphere & Health indicates that rising carbon pollution may already be influencing changes in human physiology.
Researchers Alexander Larcombe from The Kids Research Institute Australia and Phil Bierwirth of Australian National University analyzed health data from adults in the United States between 1999 and 2020. Their findings suggest that rising atmospheric carbon dioxide is linked to measurable changes in blood chemistry and bone-related minerals.
Researchers focused on levels of bicarbonate (HCO3) in human blood, a compound produced as the body processes carbon dioxide. Over the two-decade study period, they found that bicarbonate levels in the blood of American adults increased by about seven percent, reflecting a similar rise in atmospheric CO2 levels.
At the same time, the researchers observed a gradual decline in calcium and phosphorus levels two minerals essential for maintaining strong bones.
Scientists believe the changes are connected to the body’s natural response to excess carbon dioxide. When carbon levels in the blood rise, the body attempts to maintain chemical balance by releasing calcium and phosphorus from bones. These minerals help neutralize the excess carbon compounds circulating in the bloodstream.
Under normal conditions, bones are able to replenish these minerals within weeks. However, the researchers warn that if higher carbon dioxide exposure becomes a long-term environmental condition, the body may struggle to fully restore the lost minerals. Over time, this imbalance could lead to a gradual weakening of bones.
The study suggests that the trend may become more significant in the coming decades. If atmospheric carbon dioxide continues rising at current rates, researchers estimate that carbon-related changes in blood chemistry could approach the upper limit of the healthy range within about 50 years. Meanwhile, calcium and phosphorus levels could fall toward the lower limits considered healthy.
Scientists emphasize that humans evolved for most of their history under relatively stable atmospheric conditions. The rapid rise in carbon pollution over the last century has introduced environmental conditions that the human body has not historically experienced.
According to the researchers, the data indicates that human physiology has already begun adapting to these environmental changes over the past few decades. However, the long-term consequences remain uncertain and require further investigation.
Experts say the findings highlight an often-overlooked connection between climate change and human health. While climate change is widely associated with extreme weather, sea-level rise, and environmental disruption, its potential influence on biological systems may also have far-reaching implications for public health in the future.