Another good one is when they will trot out some statistic, say, 30M years ago the CO2 levels were at 4000ppm and we are doing just fine. What they seem to fail to recognize is that the only reason they have that knowledge is due to climate researchers. Somehow the deniers will accept climate research if they think it supports their position, but then will decry the researches as ignorant, as if the climatologists weren't aware of the very facts they have amassed.
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.
The latter is probably for the best, as is one of the most tedious and long fetched pro anthropogenic climate change argument (and at best a tiny contribution). We could talk about the meat industry in toto instead which is 10x worse than cow flatulence.
But is it a problem?
It's also scientific fact that ice ages happen. If the climate cycle has entered a cooling period. Wouldn't it be beneficial if we can prevent or soften it?
What exactly is the ideal gas composition for earth considering carbon based life forms?
Perhaps we can agree on "the best composition for humans"? In which case I humbly submit the answer is "the one we (and every animal we care about) evolved with".
Is science asking this question? And does science offer a clear answer here?
CO2 levels has been higher than current levels before, like back in the Triassic. Incidentally, very few humans would like to live in such a climate. It's also worth mentioning that the Triassic was preceeded by one of the worst extinction events that ever affected the planet. An extinction event caused by very high temperatures and increases in CO2 levels.
Sure, life will survive. Probably humans as a species too. The planet won't be the same as now though.
I try to research the available science but have trouble finding clear answers. The most accurate data seems to comes from the ice samples. But that only dates back 800.000 years.
You mention the Triassic period. Co2 levels were 2000ppm during that time. That sounds like a dramatic increase (from 0.04% to 0.2%). But then I also read we already often experience such levels at home or at work. For office workspace 1000ppm is considered acceptable and official limits are set at 5000ppm (as 8-hour TWA). I also read plants will grow ~5 times as fast. More faster reforestation?
We know there will be a change. But how accurately are we able to predict what that change will look like? Is there a strong consensus about it?
Offsetting something that will happen as far in the future as all of recorded history sounds a lot like looking at the horizon and ignoring the pitfall at your feet.