As everybody knows, Earth is hit by space rocks on a fairly regular basis. And a big ol’ meteor is supposed to slam into us any day now. But, it turns out, the movies lied to us about what’ll happen. If a giant meteor does slam into Earth, we won’t all die in a massive blast ala Deep Impact. Instead we’ll probably be stuck in Waterworld. Hooray?
Here’s the issue, as worked out by Los Alamos National Laboratory: The Earth, as we all know, is 70% ocean, which gives the meteor a pretty good chance of striking nowhere near any human habitation. Some whales are probably screwed, but in terms of immediate loss of life, no humans will die right away. Nor will there be any tsunamis, because it’s a lot of force focused on one point, and those waves lose power rapidly. But, this is a giant, screamingly hot rock slamming into a giant body of water, and that’s going to dump a ton of water vapor into the atmosphere.
The problem? Water vapor, when it gets high enough, is a greenhouse gas. Dumping a ton of it in the lower atmosphere is bad enough, in the sense that it will precipitate out, i.e. brace for a ton of hurricanes and floods. But in the troposphere, it’ll speed up climate change, which is already moving at a pretty dangerous clip. Essentially, if 2016 really does end with a meteor hitting Earth, it might be time to invest in real estate away from a coast.