Is the human species a keystone species? Explain. If humans were to become extinct

Is the human species a keystone species? Explain. If humans were to become extinct, what are three species that might also become extinct and three species whose populations would probably grow?

I do not think that human is a keystone species. During the human history, because humans are intelligent compared to other species, they believe that the world might exist because of them but I do not agree to this notion because humans have not been on the planet for all of the planet’s life and appeared really recently if you look at the billions of years of the existence of earth. 

If humans were to extinct, I think that some of the microorganisms like viruses and bacteria that are specific to humans would also extinct. Human extinction would help many other life forms like trees, many animals and sea life because humans are causing global warming which is dangerous for these life forms.