Anthropogenic activities are increasing the amount of carbon dioxide (CO2) in the atmosphere. There is mounting experimental evidence that lifetime exposur
A counterpoint and something to take into account:
all those studies don’t take lifetime exposure (as in “from conception to death”) into account, which might show much more pronounced effects
and the thing that isn’t directly connected: the increased CO2 levels are already causing issues for marine organisms which cannot fixate calcium for shells etc. good enough in the rapidly dropping pH levels in the oceans. I would say this is by far the larger immediate threat to humanity, because if the pH of the oceans drops too far, we will see a mass extinction that is not even comparable to the shit going on right now.
A counterpoint and something to take into account:
And thwse dissolving phytoplankton in our increasingly acidic oceans also produce something like 60 to 80 percent of the oxygen in our atmosphere.