Negative ways humans can spoil the environment is 1.using too much carbon like in cars,power plants, and green house. 2. littering and dumping trash or oil in the waters or land. 3. over fishing or some times over hunting and even poching. positive effect is 1. they have try to clean the waters and land.2. there are patrols to watch people from over fishing or hunting 3. they are trying to reduce the amount of carbon used in the air.