How do modifiers add to a sentence?

A modifier changes, clarifies, qualifies, or limits a particular word in a sentence in order to add emphasis, explanation, or detail. Modifiers tend to be descriptive words, such as adjectives and adverbs. The additional details in the sentence, by way of modifiers, engage the reader and hold their attention. 

Ithink it is 2 direct object

Ascenario where we impact the environment is when humans/ us litter outside or in the ocean which causes wild life to die or even extinct and also if we keep cutting down our trees we might not even have oxygen to live humans also keep limiting water resources wasting it s