Go read this: https://en.wikipedia.org/wiki/Anoxic_event
I don't think any amount of alarm could possibly be enough.
That is fucking miles away. At the other end, C3 plant life goes extinct if CO2 falls below 250ppm or so? So why don't you alarmists get your knickers in a twist about that "tipping point"?? If we hadn't dug up and put some fossilized carbon back into the carbon cycle (where it bloody well came from in the first place) then we'd be facing that extinction scenario instead.
Erm no. Exhaling it is just part of the carbon cycle, it doesn't make the net level in circulation go up or down, it isn't a sink or a source... the carbon you breathe out doesn't get magicked out of thin air. It comes from the sugars, fats and protein you eat which is then burnt by your body for energy, exhaled, photosynthesized by plants, consumed by animals, and moves on up the food chain where you eat it and we start again. Round and round. That's why they call it a cycle.
Without our intervention the net amount of carbon in the cycle would continue to fall due to weathering of rocks and sequestration beneath the Earth, eventually leading to the extinction of all trees and most (non C4) plant life. Luckily, we're digging it up to restore the carbon cycle to its former glory. I think about 800ppm should be our target.
In other words, low CO2 is uphill from where we are, whereas high CO2 is downhill. And the slope is steep due to the laws of thermodynamics and chemistry.
That is fucking miles away. At the other end, C3 plant life goes extinct if CO2 falls below 250ppm or so? So why don't you alarmists get your knickers in a twist about that "tipping point"?? If we hadn't dug up and put some fossilized carbon back into the carbon cycle (where it bloody well came from in the first place) then we'd be facing that extinction scenario instead.