I've been working from home today and have had the History Channel marathon of the show Life After People on in the background. This show definitely makes you think about the impact that man has had on this planet and how long will that mark last. The premise is that all of human life disappears in the blink of an eye. People didn't suddenly die so there aren't billions of bodies lying around decaying. However, there are cars left in the middle of highways or roads and everything that is automated just keeps running...until power dies.
The show starts off counting down 1 hour, 3 hour, 1 day, 1 week, etc. and takes the viewer around the world and shows what will happen to buildings, infrastructure, etc. without humans around to maintain them. It also talks about flora and fauna and what human's impact (or lack) has had on their environments.
The shows also take a look at some areas that have been abandoned so that we can see what the impact would be. And it gives an insight into our past and what the planet's future could be.
I highly recommend this series, if you ever get the chance to catch it.
This will come as a shock to you, though, the thing that makes me saddest is when they talk about domesticated pets, and dogs in particular, and how they will be trapped in their houses and may not be able to get out and if they do manage to escape, they are not trained to survive on their own and that as humans we have caused this....of course, all I can think of is what would happen to my sweet baby if I just didn't come home one day.