Question

Why does the southern hemisphere have lower concentrations of CO2?

Answer 1

Here are a couple of reasons:

1. The rate of photosynthesis during spring in the Southern hemisphere is high in locations with large forested areas (more `CO_2` consumed and `O_2` released).
2. Human activities have also impact. People are changing the natural balance by adding more CO2 to the atmosphere by burning fossil fuels (such as coal, oil, and natural gas)—whether it's to drive our cars, use electricity, or make products.

Explanation:

It is rather complicated on top of the photosynthesis effect it was shown that human activities not only are they causing the overall increase in `CO_2` levels over time, but through the effect on global temperatures, people are also controlling `CO_2` fluctuation from season to season.