is this a question where you have to pick one because i think that all of them are true. the polar ice caps are melting in both hemispheres because of global warming and ocean temperatures rising, i don’t know whether polar caps are switching directions, carbon dioxide does increase plant life because increased carbon dioxide causes an increase in photosynthesis causing spurring plant growth and finally, people are obviously concerned about the amazon rainforest because it provides around 20% of the earths oxygen and we clearly need oxygen to live. i hope that helps