Rising CO2 may already be showing up in human blood - a potentially toxic atmosphere in 50 years

For most of human evolution, the air held about 300 parts per million of carbon dioxide. It has now surpassed 420 and is climbing by more than 2 ppm per year. A new open-access study in Air Quality, Atmosphere & Health argues that shift may already be showing up in our blood.

Alexander Larcombe and Phil Bierwirth mined U.S. health-survey data covering about 7,000 people per round from 1999 to 2020. Average blood bicarbonate - the compound that carries CO2 out of the body - rose about 7%, closely tracking atmospheric CO2. Calcium and phosphorus, minerals bound up in the same acid-buffering chemistry, both fell. Extend the trendlines and bicarbonate reaches the edge of the healthy range by 2076, with calcium and phosphorus following by 2100.

The authors stress that the link is only correlational; measurement methods varied from cycle to cycle. But they argue the match is close enough to take seriously, because human physiology evolved under a stable ~300 ppm and is not equipped to handle this much extra CO2.

Previously:

• In 1986, a Cameroonian lake released a CO2 cloud that killed 1,746 people overnight

• This air quality monitor is a cute bird that dies when you need to air out your home

The post Rising CO2 may already be showing up in human blood - a "potentially toxic atmosphere in 50 years" appeared first on Boing Boing.