Yes, you also pointed out this fact up above in the comment chain as well. And as @strainer pointed out, it leaves us with more questions than answers. Specifically: how could he have participated in the study but publish a blog post that contradicts the primary conclusions of the study?
> how could he have participated in the study but publish a blog post that contradicts the primary conclusions of the study?
Short answer: Because the article doesn't contradict the study at all.
1) The rainforest is a carbon sink: It holds carbon that would otherwise be present in the atmosphere as CO2.
2) The rainforest is currently a net carbon sink: As an ecosystem it takes in more CO2 than it releases.
3) The rainforest (like most ecosystems) operates fairly close to equilibrium: The amounts of CO2/O2 consumed and produced tend to be pretty close.
4) Major ecological net carbon sinks depend less on the amount of photosynthesis in the ecosystem than they do on the sequestration of bio-matter into the ground.
5) There is ~500x more O2 than CO2 in the atmosphere. This means that the effects of the carbon cycle on atmospheric O2 are far less pronounced than on CO2.
6) net oxygen production of the amazon is effectively 0 (millions of years before a significant impact) because of 5) and 3)
In what way do any of these points contradict eachother?
The major reason (carbon cycle related, excluding biodiversity & global weather patterns & cooling etc) to care about about the amazon is to avoid releasing the CO2 already there. Purely in terms of net carbon sinking ecosystems, we should be paying more attention to our oceans as they do a much better job of sequestering that carbon into the ground.
Oxygen in the atmosphere is simply not an issue because we have so much of it.
