This might be the neatest experimental Minecraft mod that I’ve seen: AMEE mod, essentially carbon emissions in Minecraft. The mod tracks what you burn and then contacts AMEE to figure out how much carbon to toss into the atmosphere.
This might be a good way to teach about ecosystems and Earth’s atmosphere.
Of course, it’s not just wood. Loads of things burn, and not just in furnaces. The hack supports combustion of almost anything in minecraft; wood, planks, coal, tree saplings, and so on. I even put in some calculations for setting fire to cows (as any Minecraft player knows, an effective way to quickly get cooked beef). Even the hostile mobs like creepers have their emissions mapped (mostly to generic biomass calculations). I also added redstone (like electricity) emissions using AMEE’s realtime UK national grid data.