> probably due to overfishing for sandeels, their main prey
It's interesting that you point to an evolutionary fix (longevity to compensate for frequent breeding failures) for a problem caused by humans (overfishing). To me it seems more likely that if the population was at relative equilibrium for the past 100k years (seems like a reasonable assumption), then any steady increase in the number of breeding failures is a huge problem. Population dynamics are complex though, I'm not claiming to be an expert.
The actual cause is secondary to my point, be it overfishing, anthropomorphic global warming, plastic pollution, etc.
The article literally says this event will become more common due to warming and that 50-70% of the species will die off by the end of the century.
That might not be as obvious as you think. There are studies demonstrating that the parts of the brain that demonstrate consciousness in mammals, evolved before mammal and avian evolution split. With other features co-evolving later on as well.
Some birds are considered sentient now, and as more studies are performed, more and more animals are added to that list. First it was just humans, then all apes, oh and dogs, plus pigs, turns out dolphins too, and parrots, and corvids, etc. etc. etc.
At this point I'd be more surprised if they weren't conscious.
Pretty much what happens in humans when there's no contraception and therefore a new kid every ~year and less food than needed to feed everybody.
Which describes most of humanity's history. Particular care for children and the concepts of childhood and parenting are a rather new phenomenon.
Emperor penguins have an expected lifespan of 20 years, with some birds living as long as 50 years. Breeding starts when the birds are 4-5 years old. Losing one breeding attempt is not that big a deal - despite all the apparent "OMG, think of the penguins". If this event becomes more common as a result of climate change then that is another matter.