About five years ago we published this blog called is Carbon Dioxide the new Passive Smoking?

We already know that rising levels of carbon dioxide from global warming are bad for the planet. They are ruining the climate, causing floods raising sea levels, and making fertile areas uninhabitable. But are they already starting to kill us individually?

Before global warming, the average level of CO₂ in the atmosphere fluctuated around 280 ppm (parts per million). Now it hovers around 410 ppm; by the end of the century it could be around 670 ppm or even higher.

The human body can sustain low levels of CO₂ in the atmosphere-we’ve adapted to it. High levels are normally only a problem for people like building workers, astronauts and captains of nuclear submarines. Research shows that there is no question that the sorts of levels these people can meet will do you serious harm, but most of the work is concentrated around very high CO₂ concentrations at thousands of ppm, with very short exposure times , both for obvious reasons.

But as CO₂ levels rise, what happens to all of us as we breathe in steadily rising levels day in day out, without a break? Especially in places like offices, where it tends to become more concentrated.

Now a paper from Nature Sustainability by Tyler Jacobsen, Jasdeep Kler* and their co-workers looks at this question.   Some of their findings are disquieting, to say the least. Firstly chronic CO₂ exposure does seem to have health risks. There’s a long list, but the main stand outs are on cognitive ability, kidney calcification and endothelial dysfunction. Secondly, this is a preliminary paper, as the authors admit. A very great deal of work remains to be done. And that will mean setting up research programmes, signing up scientists and re-budgeting whole departments.

There is a worrying historical parallel. When the first early papers on the effects of cigarette smoking were published, they were largely ignored. Which only gave the danger time to grow. And at least individual smokers were able to mitigate the risk by giving up. But for passive smokers the risk was everywhere. If you lived or worked or socialised with a smoker, you couldn’t help breathing the stuff in. It’s the same with carbon dioxide-there’s no getting away from it

We are aware of the dangers of crying wolf, and of course it’s perfectly possible that this may not be as serious as some of the other problems currently besetting the world. But isn’t it time we researched a little, just to make sure? (LSS 11 2 2020)

Since when very little has changed, Except perhaps that atmospheric levels of CO₂ have almost certainly risen a little. Again, we stress that we don’t know the answer, and are calling for research, not immediate action. But this this blog has a lot more readers now. We include the reference below. Do you know anyone who thinks this ought to be investigated further, by practising scientists or doctors?

Direct Health Risks of Increased Atmospheric CO2

Tyler A Jacobson, Jasdeep Kler, Michael T Herneke Rudolf K Brown, Keith C Meyer and William E Funk

Nature Sustainability Review Article Vol 2 August 2019 pp 691-701

#globalwarming #climatechange #co2levels #health risks #environmental health #passive smoking #health #medicine