_____1. The presence of harmful substances in the environment
_____2. deterioration of the environment though depletion of resources
______3. energy source that cannot be depleted and are able to supply a continuous source of the energy
______4. permanent removal of trees to make room for something besides forest. this can include clearing the land for agriculture or grazing,or using the timber for fuel, construction or manufacturing.
______5. the global warming that has been going on for the past 50 years due to human activities
