Yes, the climate has changed in the past. But that doesn't mean the driver of those historical changes is driving the current change. People have always died, but that doesn't mean we shouldn't require safety devices in automobiles. Second, "cycles" is just way too blithe of a summary, as if there was a clockwork mechanism driving things. The gaps between the ups and downs is irregular.
> Why doesn't this [Milankovich cycles] ever come up?
I'm 100.00% sure climatologists are well aware of it and it has been modeled and found unable to explain the trends we are seeing.
We probably should, or take other similar-scale approaches (multiple, as it wouldn't do to put all our eggs in one basket).
The lack of response shouldn't be taken as any indication that the problem isn't dire. That would be placing a truly ridiculous amount of faith in human civilization to tackle collective-action problems, which there is little evidence we are especially good at doing.
In fact, what you see in the world is exactly consistent with an extremely dire problem and a very insufficient response.
Why the response to such a dire problem is so lukewarm is left as an exercise for the reader.
So if someone keeps bringing these things up, then it's likely they're acting in bad faith or they've been duped by someone else doing likewise.
Enthusiastic nuclear support while downplaying other sensible solutions (carbon fees, renewables, insulation and efficiency) is basically the socially acceptable face of climate change denial at this point.
There is quite some debate over the issue, but we probably have 5-30ka left of warm weather.
Because it's not responsible: it's currently a tiny downward trend that is only noticeable over millennia.
Science doesn't bring up every damn thing every damn time, because life is too short. People questioning this haven't even done high-school level reading. They're not adding to the sum of human knowledge, they're just flapping their jaws.