Virtually everything has been consistent with preparing for the worst case climate disaster. You might think that if we knew it was unavoidable it might comprise protecting populations in cities and so-forth by building huge coastal works, or moving populations, or other such huge projects, but were you to do something so overt you would instill mass panic and bring about a preemptive disaster. No. You would play a very subtle hand.
You would tighten border security, and normalise surveillance and the idea of searches, scans, and armed police.
You would instill a fear of refugees and migrants - this makes it far easier down the line when we hear how many hundreds of millions are in "temporary accommodation". They're far off. They're different to us. Callousness is a survival attribute, if the suddenly popular zombie horror and post apocalyptic genres tell us anything.
You'd saturate popular media with programmes in favour of securitised states, and which deal with unmanageable mindless hordes that need mowing down for the greater good.
You'd engage in wars which build a security apparatus and provide a distraction, while simultaneously feeding your black budgets for the preservation of the, hm, economically and socially valuable sectors of society and technology.
You hold hope around the idea of escape to another world to keep those whom might act problematically mollified until it's too late.
In your end game you start moving your population. Again, you don't want it done in chaotic panic, so you do it piecemeal. A move to the political right, you send your liberal elite scarpering to new climes, and while they're at it they pick places that they think will be mitigated against climate change because they think it might be a problem in their lives. A bit of civil unrest, more leave. Start a war. People flee. People die. Those without the means to flee get left behind - remember that desensitisation bit, and the whole concentrating upwards of wealth - if you wanted to design a system that would leave the majority of humanity unempowered and in the lurch if it all gets climatic, but give the "economically productive elite" a fire escape, you'd build it like what we have today.
I don't actually believe this either (although it would almost be comforting to, as it provides an explanation of sorts for the world), but I do wonder what home truths made Obama want to jump after his security briefings eight years ago - and that DoD report from a while back about the defence (civil and national) implications of climate change revealed a sobering level of thought has already gone into some rather dire possibilities.
It's a fairly crap hypothesis as one can't readily prove or disprove it.