[Blueflag]

Author should study the carbon cycle and botany a little better. Rapidly growing grasses are by far net producers of oxygen versus CO2. At night they are net emitters of CO2 as the cells continue respiration, but overall they are one of the best planetary sources of O2 Plants fix atmospheric CO2 into hydrocarbons during photosynthesis. So yes they 'clean' the air. But ... When plant material rots a good bit of methane is produced which is far more active greenhouse gas than CO2. Only water VAPOR (not clouds) is a greater net contributor to the greenhouse effect (which by the way does not manifest at the surface but rather much higher in the atmosphere) From a botanical standpoint an old growth forest produces an order of magnitude more methane (decay and termites) and CO2 than any manicured grass lawn. I won't contest the bit about what poorly maintained Indian gas lawn mowers do ✌️

[Paladin2]

For oxygen sustainability, everyone needs to live on an acre or more of their own. City dwellers need to go away.

[PIF]

You got it wrong ... they don’t care about the oxygen supply - totally irrelevant to the situation of a dying planet baking under the enormous strain of man-caused heat death.

If fewer people have less oxygen, then there will be fewer people, which is a good thing since the planet is way overpopulated and too many are suffering, while others like the Americans are glutinous hogs. And so forth ... you follow the logic ...