Some observations here don't appreciate what may well happen (and nobody knows what exactly will happen, though we can have a good sodding guess) when some of the effects described are felt. Sea level rise, for example, doesn't just mean that some coastal towns fall into the ocean or that a South Sea island becomes a South Sea outcrop. It means global systems, which are stacked up and act dynamically based on how each effects the other go out of "pattern". Butterfly beats its wings and all that. Milankovich cycles wax and wane on geological timescales and, as a changing variable, are not nearly as relevant to this discussion. Sea level rise of 50cm in 50 years or whatever it is (I cba to look it all up again, sorry) is a f**k ton of change in a very short space of time.
On the physical side of things it's going to affect rainfall, ice formation, soil erosion, permafrost melt, cloud cover and albedo, warm water movement yadda yadda. I could just go on and on.
Look - the physical world systems act like a snooker table where all the balls have been slung around the table all at the same time, but somehow have miraculously fallen into nearly a repeating pattern, bouncing off each other and the sides over and over. But the nearly bit is the important bit. On their own, without any outside influence, they'll still after who knows how many cycles, go out of whack, one ball will finally have deflected enough to miss another when it always hit one before, and now the whole pattern changes. Things like Milankovich cycles are someone leaning across the table, pursing their lips and blowing, introducing the slightest deflection and bringing that moment of change forward ever so slightly.
Human begins are choosing several balls and giving them a hard, sharp jab.
Effects on human society as a result of what might be considered small changes (sea level rise is not small) can be catastrophic due to knock on effects. On a small scale, an village in, say, India can end up abandoned because the prehistoric, but non-replenishing aquifer that has provided water for thousands of years is drained in ten years for a cotton crop, and now the 1000 souls who lived there now move to the nearest big city, swelling its population. The cotton crop has also replaced the food growth that fed those 1000 people so now, as well as a displaced population with no employment or income we have a deficit of food for them as well. This is something easy to understand and measure.
You can't say the same thing for global systems. We'll be murdering each other long before extinction events are even on the horizon. The price of bread and oil shot up when Ukraine was invaded, despite there being no real damage to global production of either. We are exposed, horribly, to even the slightest ripple. A more macro physical effect is going to wreck things, hard. We can have starvation and wars just because of some economic situation in one country, what do you think's going to happen if we have 20 years of, say, crop failure in some major producing country because soil salinity changed by a few percent after a few degrees of warming and rainfall pattern change?
I find it astonishing when people just take one potential climate outcome of the next 50-100 years, say sea level rise of a metre (and that's hardly bloody peanuts, is it??), and just wave it off. That sort of thing, most sorts of things, isn't nothing, confined to a few unfortunates. It's everyone.
in the headlights, short with a swift ending. Hopefully.
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