See, this is why art appreciation classes are not a waste of class time. It teaches you that artists use metaphor and symbology to refer to complicated ideas in simple images, and that political cartoons especially are rife with simplified symbology because of the limited space artists have and the complexity of many political ideas.

If you understood art and symbology, you'd recognize the treeless wasteland on the right represents the devastation of climate change, the lack of trees symbolizes environmental destruction, and nitpicking how many trees would actually be left is missing the point entirely.

But the average American has the reading comprehension of a fifth grader, so how can I expect them to comprehend a fucking artistic metaphor?

(Also: at about 116° f, leaves can no longer photosynthesize. So it doesn't matter how much CO2 is in the air - if summers get hot enough that leaves can't photosynthesize during the day, it's going to kill forests, and we are pretty close to that point in a lot of places already. But that's completely beside the point.)