I bet it would be a few percent less and the world would be a fraction of a percent better if the first result was the rainforest.

I wonder how much they pay Google for the top spot.

Amazon does not need to pay Google for this. There is no world where Google puts an organic result about the rainforest in the top spot, because it's not what most users are looking for.

At most there might be a world where Google puts someone else's ad above the organic results.

you'll probably find a Google expense for the same value of Amazon services so that no money ever trades hands, but both companies' valuations are inflated