Rising atmospheric carbon dioxide may pose long-term health risks, expert warns

Increasing levels of atmospheric carbon dioxide could pose long-term risks to human health by altering blood chemistry and potentially disrupting metabolic balance, a public health expert said.

Speaking to Anadolu, Nazmi Bilir, a specialist in internal medicine and public health, warned that even modest increases in carbon dioxide (CO2) may have physiological effects, though serious health problems remain rare under current conditions.

“Environments with slightly elevated carbon dioxide levels may lead to breathing difficulties, heart palpitations and irregular heart rhythms,” Bilir said. “However, such cases are extremely rare because CO2 concentrations do not typically reach levels that would cause severe harm in humans.”

His comments followed a study published in the Springer Nature journal suggesting that rising atmospheric CO2 could, over time, lead to measurable changes in human blood markers. The study analyzed data from the US National Health and Nutrition Examination Survey (NHANES) between 1999 and 2020, focusing on indirect indicators of CO2 exposure, including serum bicarbonate, calcium and phosphorus levels.

Researchers found that serum bicarbonate levels increased by about 7% over the two-decade period, paralleling the rise in atmospheric CO2, while calcium and phosphorus levels showed a gradual decline.

If these trends continue, the study suggests that bicarbonate levels could approach the upper limits of the healthy range within 50 years, while calcium and phosphorus levels may fall to the lower bounds by the end of the century.

Bilir said carbon dioxide can affect the body by forming carbonic acid in the blood, potentially altering its pH balance. Healthy blood pH typically ranges between 7.3 and 7.4, and even small shifts toward acidity can interfere with metabolic processes.

“pH is an extremely sensitive indicator of the body’s acid-base balance,” he said adding “A shift toward more acidic conditions may lead to metabolic problems.”

Despite these concerns, Bilir emphasized that current atmospheric CO2 levels are unlikely to directly cause widespread health issues, though prolonged exposure to elevated levels could contribute to conditions such as bone disorders over time.

Carbon dioxide is a naturally occurring component of the atmosphere, making up a small fraction alongside nitrogen and oxygen. It plays a crucial role in maintaining Earth’s temperature by trapping heat, but its concentration has increased due to human activities such as fossil fuel combustion, industrial production and transportation.

Bilir called for urgent measures to reduce emissions, including limiting fossil fuel use, expanding renewable energy sources such as solar power, and increasing green spaces through reforestation.

“There are sources that produce carbon dioxide and systems that absorb it. This balance needs to be shifted by reducing the producing side and increasing the consuming side. For example, it is extremely important to reduce traffic, industrial facilities and heating sources that rely on fossil fuels, and to make greater use of solar energy, which has been gaining more attention recently. At the same time, consumption must be increased,” he said.

“In other words, the side that consumes carbon dioxide — plants — should be expanded, or at least the decline on that side should be prevented. Increasing afforestation efforts, preventing forest fires, and ensuring early and effective intervention when fires occur are of great importance,” he added.

Safer energy sources should replace fossil fuels in buildings and urban heating systems, as part of broader policy recommendations Bilir said adding that such measures could be reinforced through formal legislation, covering heating and transportation.

“Climate laws and environmental protection regulations are now on the agenda. Expanding and supporting them will be important,” he said.