You could write about the effect that us humans are having on the atmosphere You could go in depth about the ozone hole that was created in the 1970’s and the affect it has on the polar ice caps You could describe the problems that the animals are having because they’re homes are melting or becoming unbearable due to the heat You could talk about the dramatic changes in the weather due to climate change As well you might want to list some ways that people could better their actions and stop pollution
These are only some suggestions, you don’t have to do these if you don’t want to but hopefully they give you an idea on what to write about.