Great article, and glad you brought this up. Just want to expand on the "decay/death" since it's referred to in 2 different ways in the article: 1) The decay/

Great article, and glad you brought this up. Just want to expand on the "decay/death" since it's referred to in 2 different ways in the article: 1) The decay/death of photosynthesizing organisms feed carbon to non-photosynthesizing organisms (ex: humans) and essentially neutralizes any net gain in atmospheric O2. Therefore the typical lifecycle of trees/phytoplankton doesn't add more O2 to the atmosphere than the current level. 2) In the rare instance that the decay/death of phytoplankton is quickly buried underground (ex: deep-sea mud), there is a net gain in atmospheric O2. Over the course of millions years, this process has led to ~21% atmospheric O2. So, everyday decay/death of life doesn't "produce" O2 in the way photosynthesis does, but it does when photosynthesizing organisms get buried underground.