Co2 is just a BS excuse
Although most people think that it is the Amazon, I'm sure I heard that it is in fact a huge coniferous forest which goes around the globe near the North Pole, through Russia, Canada, Scandinavia etc. just below the tundra line. At least, I think it is.
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Its called the Boreal forest or Taiga Forest (pronounced Tiger) and composes 1/3 of all the trees in the world, its trees start growing above the artic circle where they take more than 50yrs to grow bigger than a sapling because they only recieve sun for 1 month per year.
The Taiga generates enough oxygen on its own to regenerate all the oxygen for the entire planet.