Things that Human Beings could have lived without

The things I wish human beings never invented that would have made the planet a better place.

1. Plastic - While the short term utility of it seems significant and we don't seem to think we can live without it, I wish it was never invented. It is creating a mess of this planet
   
   
2. Oil - another thing we can't imagine life without, it is polluting the whole planet like nothing else and you need to dig down the crust of the earth to get it.
   
   
3. Gold - I don't understand the value of it to be mining it out of the earth. Just for for ornamental value and it is expensive too! For that matter mining in general would have been something that would have made the environment far better.
   
   
4. Concrete - it is being used instead of environment friendly materials for building, may be we couldn't have built the multistorey buildings that quickly, but another bad thing on planet earth
   
   
5. Diary - how the hell can one drink another animal's milk and create a multi-billion industry ? We are stuck to it forever it appears.
   

What's on your list ?