Temperatures are constantly rising and falling (every winter
normally)
The question is, if there is a long term development (meaning decades and centuries), and more interestingly:
How high is the human influence on that really.

Until the end of the 19th century there was a cold-period for example
(littly ice age). Wich was deviating from the average.
So when its warmer than 100 years ago, its not clear
that this is a global warming, or simply temperatures
revolving back to the long term average.

But since we measure exact temperaturs only starting at that time, if course there was warming.

Here some medium teem temperature graph over milennia.
I cant veryfy these datas, but it looks like we had a lot
of terrible terrible global warmings before.