How Climate Change Is Messing With Your Blood Chemistry

Your blood is quietly shifting to handle the extra carbon dioxide in the air.

Story Snapshot

U.S. health data show a population rise in blood bicarbonate since 1999.
Average bicarbonate reached about 25.3 mEq/L in 2019–2020, up roughly 7%.
Blood calcium and phosphorus trended down over the same period.
The pattern tracks the steady climb in atmospheric carbon dioxide.

Researchers linked long-running blood trends to rising carbon dioxide

Researchers examined more than twenty years of laboratory results from a national U.S. survey. They reported that average serum bicarbonate, a key acid-base buffer, climbed about 7% from 1999 to 2020, landing near 25.3 milliequivalents per liter in the 2019–2020 cycle. The same analysis found declines in average calcium and phosphorus, minerals that interact with acid-base balance. The trends move in step with rising atmospheric carbon dioxide over the same window, according to the authors’ comparisons.

These findings sit within known human physiology. Carbon dioxide enters blood from the air we breathe. In red blood cells, it reacts with water and forms carbonic acid, which then splits into hydrogen and bicarbonate. Bicarbonate carries most carbon dioxide in the blood and helps control pH. When inhaled carbon dioxide rises, the body often holds more bicarbonate to keep pH steady. That is the measured shift the study highlights, at a population level.

What the numbers mean for everyday health

Average adult bicarbonate generally falls within about 22 to 29 millimoles per liter. The reported national average remains inside that range. A small move can still matter if it continues for decades, especially for people with lung or kidney disease who already ride the edge of normal. The report warns that, if trends keep pace with the atmosphere, average bicarbonate could approach the top of normal within about fifty years, while calcium and phosphorus slide toward lower bounds later this century.

Public health agencies treat bicarbonate as a standard marker for acid-base status in clinical testing. Doctors use it with pH to detect respiratory and metabolic problems. A slow rise across a population signals a background shift in the acid load the body must buffer each day. That extra load can stress vulnerable systems first. A body that spends years compensating has less room to cope when flu hits, wildfire smoke rolls in, or a heat wave pushes breathing and circulation to the limit.

Mechanisms line up with basic physiology

Carbon dioxide is not just a number on a climate graph. It is a regulator of blood vessels in the brain and elsewhere. Higher carbon dioxide levels raise cerebral blood flow and can nudge blood pressure. That response is normal, but it reflects how tightly the body tracks carbon dioxide and pH every minute. Laboratory work shows that very high carbon dioxide in low oxygen can amp up inflammatory signals in blood, which hints at pathways for stress if exposures climb, though those experiments use levels far above today’s air.

This study shows that, due to climate change, our blood chemistry has shifted 7% since 1999 and will make us sick in appx. 50 years. It's called metabolic alkalosis. https://t.co/EaJxZen9Q7

— Karen Piper (@PiperK) August 18, 2026

The study reports clear, measured shifts in common lab values across many years. The mechanism that links inhaled carbon dioxide to bicarbonate is textbook physiology. The cost of ignoring an early system signal could show up first in hospital wards and in missed work across communities.

How to act now while science refines details

Leaders can cut indoor carbon dioxide with simple ventilation checks in schools, offices, and senior centers. Better air turnover often lowers illness spread and improves alertness, which pays off fast. Health systems can watch bicarbonate, calcium, and phosphorus trends in routine panels and flag outliers sooner. Households can use portable monitors to spot stale air and open windows or run fans when levels climb. These low-cost moves respect budgets and protect health while the research advances.