imagine a muggleborn enchanting a bath bomb so it works like normal but it works instantly and never dissolves so it can be re-used over and over again but then they’re showing it to their friend on the deck of a cruise ship and they drop it overboard into the ocean and because all the oceans on earth are connected it only takes a few hours for all the water in the world to be contaminated by the bath bomb and because the water cycle is broken the only potable water left on earth is the stuff that was already bottled but that runs out quickly and all the plants die, destroying the food chain and rendering Earth uninhabitable. Within a few years, earth is completely lifeless, although fragrant, and from space it is a brilliant sparkly pink.