Simply not true though. Humans emit 28 billion tons of co2 per year. That's 28 billion tons extra than was being emitted 200 years ago. Taht extra is enough to kick the carbon cycle out of balance. That is enough to be causing co2 to be rising in the atmosphere at 15 billion tons per year

Without man's extra 28 billion tons co2 per year, how could co2 be rising at about 15 billion tons per year?