The present study aims to analyze the sources involved in the distortion of the environment: global warming, human and animal migration as presented in Gun Island (2019) by Amitav Ghosh through the lens of postcolonial ecocriticism. The study examines and explores the colonial effects on nature, native land and indigenous people and animals, using the notions propounded by Huggan and Tiffin in their book Postcolonial Ecocriticism: Literature, Animals and Environment published in 2010. Blending the elements of myth, culture and history with fiction, the novel draws upon a relationship between humans and animals with ecological crisis. Findings of the study reveal that these ecological crises cause global warming and climate change which ultimately give rise to the displacement of both humans and non-humans. The study further unveils the hidden agenda behind the myth of development with intended annihilation of native land, economy and horticulture. The study becomes significant in realizing the fact that postcolonial ecocriticism is not limited to certain geographic regions but it has become a universal concern.