What will happen if humans extinct?

Human construction & expansion had began many many thousands of years ago. Some of which has been underwater. We have created huge holes in our ozone layer & melted IceCaps. We destroyed one fifth of the world's forest. Additionally, industrial activities damaged rivers & underground supplies. Today if earth's future is not taken into an account, humans can destroy this planet. However, this planet is a resilient place. In it's 4.5 billions of lifespan, earth has endured bombards of cosmic rays & meteoroids, earthquakes, volcano, frigid ice age. In all these catastrophic damages, earth can recover itself caused by human actions. If humans don't exist, the wildlife will reclaim it's place.

Litter & leaves would accumulate & it would one Chace of lightning strike to burn down all structure. The steel foundation bridges n buildings will go down. Without humans many threatened fauna will take it's righteous claim on the planet. Plants will rip apart sidewalks & concrete jungles. Within 500 years all damages to rivers, land, ozone etc will be recovered. It has happened before with Mayan civilization. Guatemala survived for 2000 years but was swallowed up by jungle at its end. Dwaraka was too underwater. So was Mohanjo daro. Several times in the history, the earth has swept clean by giant sheets of ice. The legacy of humans will be wiped by the humongous power of earth. But out of all that... What about plastic?

Plastic is a synthesized material that does not occur in wild. It will absorbed by earth with its natural erosion. Glass & concrete will turn into sand, metals will be rusted away. Plastic will be recycled with earth's natural ecosystem. Some scientists believe that plastic molecules eventually gets destroyed. There is always a possibility that microbes and bacterias will consume the plastic. Let's not create a mess on this planet. Eventually earth will play its role. Be responsible & respectful to nature.