To start, I want to say that this thread is about the Avatar film by director James Cameron and not about the animated series that is called Avatar as well. In the movie, there is this huge, Earth-size moon called Pandora that orbits a Gas Giant planet. Pandora was discovered by Earth's first Interstellar mission in the early 22nd Century, and it has fascinated humanity because it is a very surprising and wonderful world. The only problem with Pandora is that humans cannot survive more than a few minutes there, because the atmosphere contains 18% of Carbon Dioxide. That kills Earth lifeforms in a few minutes even though there is enough Oxygen, because it interferes with our blood chemistry and respiration system fatally. Now, I wonder... What would happen to the Na'vi species (and other Pandoran lifeforms as well) if they traveled to Earth and were exposed to our atmosphere, which contains only traces of Carbon Dioxide? Would they survive? My theory is that the Na'vi in Earth would suffer dramatic changes in their blood chemistry because of the lack of all that Carbon Dioxide, and they would soon die in our atmosphere just like humans die in Pandora. What do you think?