Now, there are very real concerns about a ‘tipping point’ with the Amazon. But it’s not a concern about oxygen. The Amazon doesn’t provide 20% of the world’s oxygen. On balance, it contributes almost none of it. The Amazon does produce huge amounts of oxygen. During photosynthesis, it sucks up carbon dioxide and emits O2. The estimate of 20% is too high, though: it is closer to 6 to 9%.
