Nature is always in balance, but humans thrive in a particular range of climates. 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.
We can make smart decisions when we understand the basics. For example, carbon mixed with water is carbonic acid, so it is very important for our oceans that the carbon cycle is in balance. Ocean acidification, desertification, deforestation, depletion are all tipping the carbon cycle out of our favor.
Luckily, Mother Nature gave humans the tools (like intelligence and compost) to clean up our own mess.
Here are helpful diagrams of the carbon cycle for land and water: