We cut down trees. We move rocks and parts of the ground to build houses. We take away rocks to keep. We change it by walking around on it. We grow different things on it.
Bad people litter on it.
We take things from the surface to build things. We take water from it so we can drink, that makes less water. We create air pollution which changes the surface of the earth. We create ground pollution in our water and soil. We throw away recyclables which make landfills bigger.