Again, something so easy. And again, it is just free marks. The Carbon cycle starts when , well i don't know when it starts it is an endless cycle. It begins when you breath in, oxygen goes into your body and carbon dioxide is released. This carbon enters the atmosphere, which then is absorbed by plants. they contain the carbon until night time, when they respire. The Carbon dioxide is then absorbed by the ocean, and turned into carbolic acid. But only 30% of carbon is absorbed by the ocean, some Carbon is trapped in plankton, and after millions of years, due to heating and compression, it becomes oil, which is excavated by humanity and burnt, becoming CO2 once again.
