How does pollution affect carbon cycle?
There are extra carbon it has to process through
Burning of wood, coal, fossil fuels, combustions, etc. All produce carbon dioxide, other reactions produce carbon-related molecules, such as methane. All this carbon has to go somewhere, however, there is simply not enough plants to convert all of them into oxygen.
Therefore, the extra carbon is left unprocessed, which is bad for life on Earth. And they keep on cumulating year after year and they will still be unprocessed.