Road sign confusion

ZZR1100 causes global warming catastrophe, prior to this picture the hills were covered in snow

This just came in from one of our readers in the states, Bill Clawson.

Bill gave us this comment: "This sign was posted yesterday in the scorching California Desert near Palm Springs by the local road department. High temp was 41c. Don't know what they were thinking!"

Maybe the sign was put up by this guy?