A Japanese scientist put together this montage showing every verified nuclear explosion, by country, set off since 1948. If you don't have the full 7 minutes available, fast forward to 1962 when things really get scary. Over 2,000 nukes exploded since 1945--more than half by the US. Just sorta makes me feel proud, yup.
Or, as a friend of mine said, "Now you know why any aliens lurking in orbit have never decided to land."
Watch it all. Really.