Do you know what would happen if all humans suddenly disappeared from the planet? After about one week, all of the lights would turn off because no one was there to man the power grids. After about two weeks, all of the house pets still trapped inside would pass away due to dehydration or starvation, while the rest took to the streets in search for food. After one month, all the nuclear power plants would become unstable, leading to nuclear meltdowns across the entire planet.

After about one year, any city not affected by nuclear fallout would be completely reclaimed by Mother Nature, and all of the satellites would start to fall back down to Earth. After 200 years, all of our largest buildings and structures would begin to collapse. Within 35,000 years, the plant cycle removes all traces of lead left from the Industrial Revolution from Earth's soil. 65,000 years after that, CO2 levels in our atmosphere return to pre-human levels.

Mount Rushmore survives for 7.2 million years before finally caving in, and the last traces of humanity will be our bronze statues and cities buried underground like some sort of techno-fossil.