1) Fossil fuel signature in air and coral.
2) Less heat escaping out into space.
3) The Ocean warming pattern.
4) Nights warming faster than days.
5) More heat is returning to earth.
6) Winter warming faster.
7) Cooling upper atmosphere.
Thinking about No. 4 and perhaps 5, nights warming faster than days is an indication of GHG increased warming. Many climate skeptics argue that the Sun is the cause of our increased planetary warming but surely a signature of solar warming would be the opposite and days would warm faster than nights?
Anyway, all these 'finger prints' seem well supported by empirical evidence and research and most were predicted to happen as a result of AGW BEFORE they were detected. It is also worth noting that none rely on computer modelling which seems to be a catch all reason for many to reject the science.