Well... plants breathe CO2, so. :) I actually wonder if, in 100 years, how the oxygen content will increase if this greening continues? It'd be wild to consid

Well... plants breathe CO2, so. :) I actually wonder if, in 100 years, how the oxygen content will increase if this greening continues? It'd be wild to consider a 27% oxygen environment on Earth in the year 2100. Which would also cause problems of its own, as I imagine you might have a higher risk of fires, since you have more available oxygen.