We hear a lot about waste, these days, in part because we are generating a lot of it. Everywhere you look, landfills are being filled up, stuff that was previously “recyclable” is no longer accepted (because China no longer wants to generate pollution from burning it), and the garbage patch in the ocean is growing.

The average American produces approximately 1,700 pounds of garbage per year. Most of that garbage cannot be recycled — or rather, it won’t be recycled because it isn’t cost effective to do so. Most of that plastic that you bother to sort will all end up in a landfill anyway.

Why don’t we just throw it all into a volcano?

Yes, the idea seems like the sort of thing that would be suggested by an eight-year-old on a sugar-fueled rampage. (Which, by the way, might just be a convenient excuse.)

But why not do it? Could it work? Could we “pave over” our garbage by putting it into a volcano, out of sight and gone for millions of years beneath the Earth’s crust?

Unfortunately, there are some issues, both with this and with some other suggested-by-eight-year-olds disposal ideas.

Lava (like this idea) is kinda dense

The first big issue with chucking stuff into a volcano? Density.

Namely, it’s the fact that lava is molten rock. Liquid rock is very hot and it sloshes and flows around, yes, but it is still rock. And rocks are dense.

When we drop some garbage, such as an unwanted toaster, into water, it sinks. The toaster is denser than the water, so it falls through the liquid water to end up at the bottom of the tub, ocean, lake, wherever.

Your kitchen toaster, however, is not denser than rock. So if you were to toss the toaster into a volcano, it wouldn’t sink below the surface of the lava like the Terminator sinking into a vat of molten metal. Instead, it would stay on top, like a boat on a very, very hot lake.

It would still burn, but now we just have burning garbage, with all of the fumes and smoke rising up from our pile of trash-on-lava. In other words, throwing trash into a volcano is a lot more effort, for the same outcome as burning it in an incinerator…

Volcanos have no filter

…except that isn’t even correct! Most industrial incinerators have two features that are missing from volcanos:

1. When trash is burned in an incinerator, it typically generates electrical power for the community. No electricity from the volcano.
2. Incinerators are fitted with scrubbers, designed to remove most of the pollutants from the air before it is released. A volcano has no system to remove pollutants.

So when you throw trash into a volcano, you’re burning it, without the benefit of generating power, and putting out more pollutants than if it was burned in an industrial incinerator.

All those pollutants would introduce a pretty serious safety risk for any residents living near the volcano, breathing that air. The fumes could be carried long distances, putting others downwind at risk as well, and dangerous compounds that are released into the air could contribute further to man-made climate change.

Of course, even up close, there’s some real danger of throwing any old trash willy-nilly into molten rock.

Volcanoes are not the safest place to chill

Even if, despite the concerns above, we decided to go ahead with our chuck-all-our-garbage-into-the-volcano approach, we’d have some safety challenges.

First, an actively erupting volcano is not an easy place to access. You’re going to have to haul your garbage a long ways from civilization — which makes sense; most people don’t want to live right near an active, erupting volcano. You’d have to either construct roads, which would be in danger from the eruption(s), or you’d need to fly in the garbage, which would be prohibitively expensive for heavy, large amounts of waste.

Second, depending on what gets thrown into the lava, there can be some pretty severe reactions. Here’s what happens when about 30 kg (66 lbs) of organic waste, containing a fair amount of liquid, was chucked into a volcano:

Even from a small amount of liquid, the lava reacts violently, as the liquid is converted to steam and massively expands. When water turns to steam, it expands to approximately 1,700 times its original size. That can lead to a pretty significant eruption/explosion, which would definitely not be safe for any nearby workers.

Finally, most volcanoes are not constantly erupting. Some, like those on Hawaii, do produce steady, constant lava flows that could be a target for trash. Most volcanoes, however, are pressure chambers. When you see lava from most volcanoes, it is actively exploding out under high pressure, and you cannot simply walk up and sedately chuck in your garbage bag.

What about nuclear waste?

Okay, okay, volcanoes aren’t going to replace landfills any time soon for our general purpose trash. But what about some of the nasty stuff, like spent nuclear fuel rods or other radioactive waste? Could we put that into a volcano?

Unfortunately, once again, not a good idea. In this instance, the lava isn’t hot enough to make it worthwhile! Lava is typically around 2,400 degrees Fahrenheit (1,200–1,300 degrees Celsius), which is pretty hot — but not hot enough. The casings on nuclear fuel rods are made of zirconium, which melts at about 3,370 degrees Fahrenheit. The uranium itself doesn’t melt until 5,189 degrees Fahrenheit — more than twice as hot as the lava.

If you chuck some fuel rods into a semi-dormant volcano, you’ll just end up with radioactive fuel rods sitting in the newly formed rock, and probably still pretty close to the surface.

Things would get even worse if you threw the spent uranium waste into a volcano that was actively erupting. You’d end up with radioactive bits and pieces scattered all over the eruption zone. Even worse, some portion of radioactive material may be carried in the ash and gas that is released, spreading it over thousands of miles.