I was recently asked by a fairly small and young human why we don't just throw a lot of our waste into volcanoes – specifically, into the ones that have lava lakes, like Hawaii's Kilauea or the Democratic Republic of Congo's Nyiragongo. It's a surprisingly good question; after all, we already burn trash, so why don't we let nature take care of it for us? Better incinerated in a hellish pond ban floating around waiting to be inadvertently eaten by fish, right?
It's certainly a question that deserves an answer. Well, sadly, that answer probably isn’t the one you’re hoping for. As I've explained in a previous Forbes piece, lava lakes are complex things. They're extremely hot, and can melt plenty of things, that's for sure. However, they can't melt everything, and humanity has invented plenty of materials that would simply float atop the surface.
Secondly, lava lakes aren't infinitely deep. All that melted trash has to go somewhere, and although some would disappear in plumes of smoke and vapour – the type that would be incredibly harmful to breathe in – much would be subsumed within the lava lake. The rubbish wouldn't simply sink into an infinite oblivion; as frightening as lava lakes are, they still have a finite volume, and it’s often on the move up and out of the vent. This means that the polluting remnants would erupt out into the surrounding landscape, which would contaminate the soil, or they would be jettisoned skywards in a fire fountain, meaning the hazardous lava droplets that scatter and splatter everywhere would now be not only scorching hot, but toxic.
Worst of all, lava lakes are often incredibly unstable. If you suddenly pierce the surface – especially with something that's wet – you can trigger an immediate chain reaction of explosions involving highly pressurized and acidic steam, as well as lava blebs and bombs. Suffice to say, dumping trash into lava lakes would never be a job you could get health insurance for.
Lastly, lava lakes are rare. Most volcanoes don't have them, and right now, only a handful exist around the world. It's unlikely that somewhere like Hawaii would be happy to take on billions of tonnes of the planet's rubbish every year, especially considering it's not a great way of disposing of trash in the first place. Even if it did, the shipping distance would increase the carbon footprint of the waste disposal by magnitudes - so not only would we be massively polluting the local environment, we'd be giving climate change a huge helping hand too.
Sorry to burst your bubble, but using volcanoes to destroy our waste is simply a rubbish idea.
