You humans have no respect for your planet. Do you know what acid rain is, Ben?
No, Thanos, what are you talking about?
Wow, Thanos, that is terrible! Is there anything we can do to fix this?
When you humans carelessly burn fossil fuels and coal, the waste gases, sulfur and nitrogen oxides, makes the precipitation acidic. This has VERY negative effects to aquatic life, forests and other vegetation you fool!