Perhaps, but it is a strange coïncidence then that they've been going up since the Industrial Revolution, which also happens to be when humans started releasing a whole bunch of carbon (a greenhouse gas) into the atmosphere.
It took a while for us to develop the science of climatology and then start noticing natural climatic cycles as well as then noticing anthropomorphic climate change (ACC):
* https://en.wikipedia.org/wiki/Climate_change#Terminology
Natural cyclic oscillations are known and have been taken into account:
* https://en.wikipedia.org/wiki/Pacific_decadal_oscillation * https://en.wikipedia.org/wiki/Atlantic_multidecadal_oscillat...
The possibility of being wrong is there, but here's the thing: if we're wrong about ACC being real, then the worse that will happen is that we move towards more efficient and renewal infrastructure (which isn't a bad thing in itself). If we're right about ACC being real, and do something about it, then we (may) save human civilization.
There's not much long-term downside to assuming ACC is real and doing something about it.