The earth has no "normal" temperature. Point of fact, its temperature has been changing for the past 4,540,000,000 years (+/- a week or two) and will continue to do so for the foreseeable future.

And there's not a fucking thing we can do that will stop it.

Further, if you don't know what "normal" is, it necessarily follows that neither can you know when it isn't normal.

Anyone who tells you any different is blowing smoke up your ass.