ecological vs environmental

ecological

adj
  • Relating to ecology, the interrelationships of organisms and their environment. 

  • Not harmful to the environment. 

environmental

adj
  • Pertaining to the environment. 

noun
  • Any factor relating to the physical environment in which hardware is operated, such as the room temperature or the number of racks used to hold equipment. 

How often have the words ecological and environmental occurred in a corpus of books? (source: Google Ngram Viewer )