History records a mini ice age in the 1400s (I believe) that had many rivers in Europe frozen that had never been frozen before. Which internal combustion engines were responsible for the subsequent warming? The earth goes through periods of cooling and warming which does not mean that mankind is responsible for it.
I personally doubt the cause is man but it definately warmer today in NE in the winter than it was in the 50's. I don't need temperature records for that.
London used to hold markets on the frozen Thames river in those days as well. When was the last time the Thames froze over enough to hold a market on it in the City of London?