Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: Jannine Novak on 07/03/2009 12:30:02
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Jannine Novak asked the Naked Scientists:
Dear Naked Scientists,
I love your program (http://"http://www.thenakedscientists.com/podcast") and listen to it everyday in the car, on my way to university with my Mum. A little while ago, we came up with this question we wanted to ask you:
Since the CO2 levels in the atmosphere have been rising, how is this affecting human physiology? I know we can adjust to different conditions, but that doesn't make it optimal for our bodies (and brains) to function.
Thank you,
Jannine
What do you think?
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Hello Jannine
The answer is that people could be affected by elevated CO2, but only if the level rose considerably and very fast ie. in minutes. This is because we can metabolically compensate for elevated CO2 in the body.
Take, for example, people with lung diseases. In individuals with fibrotic / restrictive lung diseases where gas exchange is impaired the CO2 level in these people can climb to very high levels. But the body adapts to the chronically elevated CO2, which is an acid anhydride (of carbonic acid) by excreting hydrogen ions via urine. Urine therefore becomes acidic, and the levels of bicarbonate in blood therefore rise to offset the acidifying effect of the CO2. Thus the affected person runs a higher CO2 but with normal blood pH.
Because atmospheric CO2 owing to climate change would alter only very slowly there would be plenty of time for people to compensate metabolically for this effect and therefore most people would be fine.
It's more likely that the world would have been plunged into some other sort of catastrophe triggered by the high atmospheric CO2 before humans died from it....which is reassuring in some ways, but not in others...
Chris