Our predicament is crucially different from, say, being ten minutes after the launch of mutually assured nuclear destruction, where human society really has only minutes or hours left and hugging loved ones is almost the only expression of humanity left. Instead, we are in the (in some ways worse) situation of having a disaster (or series of interlocking crises) that will unfold across decades and even centuries and millennia (the effects of our injection of CO2 into the atmosphere will be felt for hundreds of thousands of years, species extinctions are forever and could well lead to ecosystems that are radically different - and for a very long time much simpler). What this means is while some shocks could be quite sudden (as we saw in 2008, banks can (almost) collapse within 24 hours if conditions are right, or rather, wrong), industrial civilisation will not go down in an afternoon (barring global nuclear exchange). Such an outcome is likely to take decades and a whole series of crises.
Many "catastrophe porn" films like 2012 (which I haven't seen) only further corrupt our moral imaginations by asking us to imagine ourselves in pure survival mode, which is a form of ethical laziness, since it is much more likely the real crises will bring moral challenges considerably more complex than "will I resort to cannibalism to stay alive?" (The Road). Neither Mad Max or Star Trek are particularly likely in the coming decades, but I expect something more in the ballpark of (the background scenes of) Children of Men.
In our contemporary situation, there are still plenty of good ends to pursue, even if it is increasingly unlikely that our actions are going to "save" civilisation as we know it. Whether we conceive ourselves as offering societal palliative care or building arks for the coming storm, there are more options than trying to plug the hole in the Titanic as it goes down (to mix three metaphors in as many lines). If we are offering palliative care for industrial society as a terminal patient, then perhaps that patient is a pregnant woman and our care may yet save the baby. That is, the choices we collectively make now will significantly influence the basic conditions under which any future society will exist, including (through the climate, health of biodiversity, soils, oceanic chemistry and so on) the carrying capacity of the planet and its regions. So it may actually now be impossible to keep things going as we've known them for the last few decades (let alone with continued growth) for too much longer, but it is certainly possible for us to bequeath a better or worse world to our children.
The perception of being "too late" will only increase in the next few years and this could well lead to all kinds of hopeless responses (nihilistic hedonism ("eat, drink and be merry..."); populist quick techno-fixes; authoritarian paternalism; scapegoating of outsiders). Our concern is not to say ahead of time what ought to be done (though many of the things that ought to be done now are more or less clear), but to focus on the formation of human beings who will not respond to such perceptions out of fear, guilt or impotence, but from faith, hope and love.
I took the title of this post from this helpful article. Other good posts on a similar theme include this reflection on the motives on doomers from one who has experienced them and this piece on collapse porn.