> Saying the Amazon rain forest is the Earth's lungs has lots of metaphorical applicability. It speaks to people's intuition about how forests cycle water aroun

> Saying the Amazon rain forest is the Earth's lungs has lots of metaphorical applicability. It speaks to people's intuition about how forests cycle water around the planet as a quasi-respiration organs, very much like gas- and water-exchanging lungs. And with similar importance to the “organism” of Earth's biosphere. I've always heard the metaphor accompanied tightly by the claim that it's a significant fraction of the Earth's oxygen production, and denying the metaphor seemed to me to imply nothing further than the refutation of this fact, particularly in light of the first paragraph's strong claims that avoiding deforestation is important. I just don't see why it's critical that he emphasize that point in the firm of holding up the existing metaphor. I read the article (and I think the author intended it) as a pretty classic popular-science case of "here's a common misconception", and as shallow as that may be, it has value. At any rate, it ounds like we're on roughly the same page overall, and our remaining differences are starting to inch towards pedantry. Thanks for the conversation!