> probably the best approach involves reusing existing plant or algae species. and simply harvesting them to bury in such a way that they won't be uncovered for

> probably the best approach involves reusing existing plant or algae species. and simply harvesting them to bury in such a way that they won't be uncovered for a couple hundred million years. As a bonus, you're helping out a future civilization by seeding their oil reserves. Talk about paying it forward...