It is reported that the northern hemisphere is relatively densely populated, and human activities such as burning fossil fuels continue to push up carbon emissions. 
the carbon dioxide concentration in the atmosphere of the northern hemisphere has reached the benchmark level of 400 ppm in 2013. Relatively speaking, there are few human activities in the southern hemisphere, and Antarctica is sparsely populated, but even so, the carbon dioxide concentration in Antarctica reached the benchmark value of 400 ppm in June 2017.
The concentration of carbon dioxide in Antarctica will not fall below 400ppm