The answer is (1) because the carbon in the trees is released when it burns and this is the cause of global warming (in part)
It is not (2) because, I don't really know but it's not.
It is not (3) because it is exposing more sunlight and even that hardly affects it
And it is not (4) because biodiversity is the variety of species living in the forest so cutting them all down would just destroy their habitat and they would have to leave.
In order to higher the population fishing efforts should be lowered, in order to lower the population fishing efforts should be higher.
It's called chemical reaction.
(I'm not real sure)
