So the carbon dioxide that humans and other animals exhale is simply returning the carbon dioxide that was briefly sequestered in plants to the atmosphere.
(the carbon dioxide; humans; ) (the carbon dioxide that humans and other animals exhale; is simply returning; the carbon dioxide that was briefly sequestered in plants to the atmosphere) (the carbon dioxide; was sequestered; L:in plants; T:briefly)
the carbon dioxide the carbon dioxide that humans and other animals exhale the carbon dioxide
humans is simply returning was sequestered
the carbon dioxide that was briefly sequestered in plants to the atmosphere
L:in plants T:briefly