Yes it is "normal"

Look into the history of the planets climate and the evidence of the warming and cooling cycles through history.

I still do not believe that man has much if anything to do with "global warming" as that still smacks of hubris coupled with chicken little syndrome two things that man as a species seems to have in abundance.

Of course man effects the climate because everything does so I guess we could always blame the dinosaurs for their warm cycle swing as well.

Now the only thing AA is right about and it is quite small and WELL known is that the sun plays a part in the cycle.