I don't think weed will become extinct. Hydroponic cultivation of it has increased its potency amillionfold and has caused it, through human intervention, to become one of the most hardy and flourishing species of plant in the world.

Still somehow I feel uncomfortable with wasting it, I guess mostly because I don't wanna spend more money than I have to, other people can do what they want to I suppose.

And of course we can run out of the world's natural resources, especially the example you mentioned. The way we are handling oil is horrendous, and causes so much unneccessary conflict and death because we're RUNNING OUT and desperate for more of it from other parts of the world, wherever we can get it.

I wonder whether there could be similar social consequences to not conserving weed, affecting the lives of people who are somehow related to the drug trade. Whatever the effects, I'm sure they're not quite as extreme, but that's still why I'm uneasy with wasting it, because I DON'T KNOW what it does.