While I doubt that Al will run as a Green, it is a delightful idea. There is one fact that adds to the plausibility of the idea. What many don't know is that Al Gore was selected by Larry Page and Sergei Brin of Google as an "advisor" right after he lost the 2000 election. They gave him an undisclosed amount of stock for his advice. This was back when they were private and when the private stock was still relatively cheap.
Here is the incredible, if under-reported, fact. Should the Goracle choose to run, he could finance much or most of the cost of his campaign right out of his own pocket. It will come out later, but he has over $100,000,000 of Google stock and he may have as much as $500,000,000. Normally anyone with such a huge stake would have to disclose it, but Google is worth so much that even 1/2 billion dollars of Google is "non-material".
He's got OXY stock, how much I don't know, but what else ?