take the large number of things that you think that "effects of humans" may signify, which are all effects of humans, which is all effects to this planet wether it be economical or meteorological or physical (being "changes to the actual face of the planet, different than what nature has created"), which have only become truth in the time that humans have existed and procreated on this earth, and you will have the answer. im not ambiguous. thats an easy assumption from my statements.