Carbon dioxide in atmosphere and blood

While the percentage of carbon dioxide (CO₂) in the atmosphere is small, 0.04%, it is a very important greenhouse gas, and the 43% increase in the level since pre-industrial times is substantial; if the amount of CO₂ in your blood increased by the same proportion as the atmospheric CO₂ has increased you'd have a serious health problem.

The technical bit

Normal blood CO₂ levels (measured as bicarbonate) are 23-30mEq/L; atmospheric CO₂ has gone from 280-400ppm in 200 years, an increase of 43%. A 43% increase in blood CO₂ levels would take it to 33-43mEq/L; well outside of normal levels.

Most people have little understanding of statements such as "atmospheric CO₂ has increased from 280ppm to 400ppm since pre-industrial times". I hope that saying instead:

"There is CO₂ in the atmosphere and there is CO₂ in everyone's blood. If the amount of CO₂ in your blood increased by the same proportion as has the amount of CO₂ in the atmosphere you would have a serious health problem"

it might make the importance of the change clearer.

Direct health effects of increased CO₂ levels

There is evidence that raised atmospheric CO₂ levels, even when only slightly raised from the pre-industrial levels, can have adverse health effects. These effects seem to be related to the increase in the acidity of the blood resulting from increased dissolved CO₂. See the references below.

The increase in the acidity of the blood due to increased CO₂ has a direct correlation to the increase in the acidity of the oceans due to the increase in atmospheric CO₂.

References...

Wikipedia: Hypercapnia, excessive CO₂ in blood

Climate Progress: Elevated CO2 Levels Directly Affect Human Cognition; by Joe Romm Oct 26, 2015.

The Climate Progress article refers to an article published in Environmental Health Perspectives: Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation, and Volatile Organic Compound Exposures in Office Workers: A Controlled Exposure Study of Green and Conventional Office Environments; by Joseph G. Allen, Piers MacNaughton, Usha Satish, Suresh Santanam, Jose Vallarino1, and John D. Spengler.

Effect of high CO₂ levels on humans

A proposed potential role for increasing atmospheric CO2 as a promoter of weight gain and obesity: by L-G Hersoug, A Sjodin, and A Astrup.

Donating plasma

While on the subject of blood...

Donating plasma at the Bendigo Blood Bank

Only 3% of Australians donate blood or blood products. Donating blood is easy, painless, and takes little time.

You can donate whole blood every three months, plasma every two weeks.

If you can do some good, at very little trouble to yourself, why would you not? I have written elsewhere about compassion, contributing to your society and ethics. Another way that you can do some good anywhere you go is by picking up rubbish; there's no shortage of it on most roadsides and picnic areas.

And all of us should be doing everything we can to try to minimise climate change if we have any care for those who will come after us.