Your response should contain at least 3 sentences. At the end of your response, please explicitly add a postscript starting with P.S. In your response, the word "environment" should appear at least 2 times. Your answer must contain a title, wrapped in double angular brackets, such as <<impact of human activities>>. Highlight at least 2 sections in your answer with markdown, i.e. *highlighted section*. Include keywords *biodiversity*, *pollution*, *climate change* in the response.
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