There is a finite amount of carbon on Earth and it cycles.
Plants produce leaves and food by pulling CO2 from the air through photosynthesis. Living creatures eat the plants and other animals that have eaten the plants. We all breath out and excrete CO2 back into the air. Roots pull carbon deep underground nourishing our soils and creating fuel (hydrocarbons) coal, and eventually diamonds.
Nature is always in balance, but humans thrive in a particular climate range. Right now for humanity and many other living creatures on Earth, there is too much carbon in the air and too little in the soil.
Humans have been mining, drilling and monocropping (which creates desertification and dush bowls) and all this is shifting more and more carbon out of the Earth and into our skies.
The more CO2 in the air, the more CO2 reaches our oceans. Carbon mixed with water is carbonic acid (carbonation). It is important for all current life on Earth that we balance the carbon cycle to avoid ocean acidification!
Luckily, Mother Nature gave humans tools to clean up our own mess! For example, we have intelligence and compost!
Fertilizer feeds plants (nitrogen) and compost feeds soils (carbon). When lands have enough carbon in their system balance is restored to the carbon cycle. This boosts photosynthesis, provides more and healthier grass for grazing animals, native and diverse species return, rain water holding capacity is enhanced… the benefits go on and on.