Method of the world's destruction: climate change, accelerated by a group of geeky mad scientists accidentally starting a war with a bunch of witches by creating a wormhole that could possibly destroy the planet.
I loved this book. It's weird and hard to classify, but that just makes it all the more interesting.
First of all, don't make the mistake of assuming it's teen fiction. It starts off like teen fiction, including centering around two very specially special talented kids, and every adult they encounter is, stereotypically, a complete a$$hole. One kid is a super-genius science geek and the other is a nerdy witch. They have a weird encounter that results in some considerable craziness, and the children are separated as one is admitted into a school for witches and the other is admitted into a math and science school, where the elite brains of modern science can keep an eye on him.
Fast-forward some twelve or fifteen years, to the children as twenty-something adults. Neither one is ruling the universe; the science geek has been employed as a significant but not lead player in a Steve Jobs style geekathon corporation with plans to create a wormhole through space to another planet if this one goes belly-up; and in the meantime, the witch has been hemmed in with a whole group of hipster witches who police her for Aggrandizement (note the capital letter) and engage in a little magical ecoterrorism. The only thing these groups have in common is their lust for lattes. And the two characters dance around each other in a very human relationship that might actually be real love, while the world falls apart around them through a combination of climate change accelerated by the witches and the mad scientists running afoul of each others' goals. The climax serving as a backdrop for the awkward romance and sexual relationship that develops between the two.
Some other reviewers found this annoying. I did not. To me, it brought to mind some Terry Pratchett or Douglas Adams style obsurdities. I liked the fact that the characters stopped to be human during disaster, because that's what humans do. I like the fact that denial was a tragic flaw that both protagonists struggled with.
It's a quirky sort of book, and it's hard to classify and it's not perfect. One thing that's a little odd is that it almost reads like two books; the teen fiction book, and the mature love story cleverly disguised as science fantasy. Another thing is that the guy that you figure is going to be the big bad villain of the book... just isn't. Really; nothing happens. I love it because it's almost Game of Thrones like in its bucking of tropes, but I can see how it might confuse some readers. But it didn't confuse me, so if you can handle a little absurdity, I highly recommend it!