I think my biggest mistake of my life was driving my diesel truck around the fertile crescent of the middle east, in which the whole area eventually became a desert over 1000s of years.
That or the antarctic a little earlier....those poor mammoths!
I remember going to a family get together back in the 1980's. . .in January. . .because there was no snow and it was warm. My parents told me about a couple of time when they were young (1940s-1950s) that it snowed. . .in June.
