What you have so far is solid and straight-to-the-point. However, I would adjust it slightly in order to be more shocking to your audience.
Here is my suggestion: "Smog pollution is affecting earth's air quality and is causing the planet's temperature to rise at a rapid rate, which can be detrimental to all of earth's species if it is not controlled soon."
I am not entirely sure what your topic is or what you intend to persuade your audience into believing, so you can change what I have written into what works best for your essay. I would recommend adding an interesting/scary fact into it in order to convince your audience of the importance of your topic.
