co2 makes you fat, page-16

Human can probably apply to a number of things. This is from a quick look at various references on the net.

If you are referring to the animal species of which all readers here are members, then it's Homo sapiens.

If you are referring to the genus Homo, then it includes other related species. Except for the sapiens species, the last of other species (floresiensis) is thought to have died out around 12,000 years ago and the species neanderthalensis is thought to have died out about 24,000 years ago. This genus is thought to be less than 2.5 million years old - so no member would have experienced CO2 levels as high as this if the research above proves to be correct.

If you are referring to the sub-family Homininae then it includes humans and some other primates, such as gorillas and chimpanzees.

If you are referring to the family Hominidae then in addition to the sub-family above it includes other primates like orangutans. Hominids probably evolved less than 15 million years ago.