Respuesta :
Answer:The last time levels of atmospheric carbon dioxide were this high came during the Pliocene Epoch, which extended from about 5.3 million to 2.6 million years ago
The amount of nutrients present in the tropic level is called the living state.
The accurate answer is very complicated as the amount of carbon dioxide is changes gradually every day. Therefore the exact date to the same ratio of carbon dioxide is difficult to tell.
In my opinion, the amount of carbon dioxide is high as it if for today is 20 years ago when ozone later starts depleting.
Hence, the correct answer is 20 years ago.
For more information, refer to the link:-
https://brainly.com/question/19524691
