It has come to my attention that this world ultimately revolves around money. Sadly that is how it will be for a long time, or at least until there is enough resources for everyone that money won't matter, and that brings me to my short, resources. Natural gas is going to run out eventually, and making it is expensive. (and yes it can be made the same way diamonds are, intense pressure and intense heat, just not cost effectively).

 

So that brings me to my short. Petroleum reserves will still be here but not forever. So when reserves run dry and all that equipment they have is worthless, that company will be worthless. I will be waiting for that day :3, maybe by then I'll have a billion dollars to short XD. Just a play to keep in mind. Keep that play in your head for 50 years or so, assuming you are young. 

A good long in my opinion would be Tesla, hydrogen is the next best thing after natural gas. Edison may make a come back too. This may not be your strategy, but keep this in mind on the side. :P Renewable energy is better, but cheaper, and least not right now.