Love this! I suppose this is easy enough to do with satellite imagery.

Next up, I would love a noise pollution map. And every time I think about it, I think it just needs to be an opt-in, kind of SETI@home type global network of people wanting to submit decibel levels from their smart devices or any kind of device really into a global database.

Then people could be careful about where they rent a house or an apartment by maybe a busy place that they don't hear the sound pollution at the time they visited it, but can look later after they leave the tour and say, oh, it's actually really noisy there at 10:00 at night and I'm not going to sleep very well.