OUR RECOMMENDATION
Tell all the people from Los Angeles to stop polluting.

My recommendation is to stop all cars going around Grand Canyon because most pollution comes from cars, trains, and planes. Another recommendation is to stop people from burning wood or coal but that would cost five billion dollars. 

POSITIVE CONSEQUENCES
Make less pollution, and the you could see better

So the animals could live, and the horn toad can breath clean damp air.

NEGATIVE CONSEQUENCES
If some people pollutes more it will be worse, and it will cost a lot of money.

If the people that visit Grand Canyon a lot will not visit it no more, cause of the haze and the pollution that cause it.