There is a new paper that chronicles the effects of the gradually earlier arrival of spring in the arctic to one of it's spring/summer inhabitants; the Red Knot (Calidris canutus). What happens in the arctic does not stay in the arctic.
It's easy to forget that what we're watching has already had significant impacts -- pushing some species to the edge of extinction.
Easy indeed. But for entirely different reason, for some people (myself included) than the one you presented.
Sure, species will extinct. Sure, it's sad. Sure, it's very important per se, species extinct is a big-time tragedy on its own, it took millions of years for them to evolve, and now they are disappearing pretty much forever in human civilization terms. Arctic ecosystems' damage and potential collapse, biodiversity loss, medicine potential wasted, ethical reasons - all true.
But this is just... _insignificant_ in compare to real big consequence of blue ocean Arctic - which is disastrous (for modern civilization) global climate change. Which is why it is indeed easy to forget about some particular species going extinct - because it's insignificant in compare to other things involved.
Should Arctic go blue, whole planet gets BIG time problems, humans included. I'd say that mentioning particular species loss without mentioning havoc to world-wide climate - can even be seen as an attempt to distract people from this "real" - much more important in terms of human existance, - consequence of the melt. This is one psychological method of presenting relatively non-important consequence - to try make the "cause" to look relatively non-important too.
There are many papers and articles on the subject, like
this one for starters. But, i think i can sum up the problem off the top of my head and expand on what (probably) is said in that one, too. Quickly. Loss of summer sea ice in the arctic, by itself, will result in at least the following, afaik:
- warmer oceans worldwide, with new monstrous El-Nino-like regularly devastating big parts of Earth after few decades of summer-ice-free Arctic;
- warmer athmosphere worldwide and especially in higher latitudes of Northern Hemisphere, with direct consequences like many times more forest fires - this is already ongoing trend, yep - in boreal forests belt of Earth, causing massive further emission of greenhouse gases and directly destroying mankind's remaining wood supply, lots of biodiversity, and much infrastructure;
- hundreds-gigatons-scale (at very least) geologically extremely rapid release of methane from Arctic land permafrosts and from methane hydrate deposits within large shallow shelves of Arctic ocean, thus massively accelerating warming worldwide (and thus further worldwide species loss, agriculture problems, desertification increase, many big ecosystems worldwide going nuts, etc);
- complete melt of Greenland ice sheet (may well happen much sooner than most people think - all the thick sheet won't sit on its bottom and melt steadily, nope, it will fracture and slide), the point is, though, that sooner or later, that's some +6...7 meters to sea level worldwide from Greenland ice alone, which means ALL the fertile river deltas in the world will be lost to agriculture, lots of real estate, infrastructure, lots of big cities and some small states - all will be for all intents and purposes destroyed by ocean water.
I hope this tiny humble review of Arctic sea ice importance for the planet as a whole and for us humans in particular - would remind everyone here that what we discuss is way, WAY more important than some issue of "oh, some polar bears and alike will go extinct! It's terrible!".
P.S. And of course, once Arctic summer ice is mostly gone, it will take currently _NOT_ available technical means, - akin to industrial-scale, profitable thermo-nuclear reactors powering up most of mankind and able to provide lots of power on top of that, in order to "freeze back" the Arctic. It is currently unknown whether such technical means would ever actually be available, too. So losing summer sea ice is kind of great indicator, too: it is MUCH easier (and safer!) to prevent the loss than to get back to normal sea ice cover once it's nearly summer ice-free. So, if much easier part won't be done, then why exactly could we expect much harder way to ever succeed?
P.P.S. The most important elementary physics fact to understand when considering summer-ice-free Arctic ocean - is the fact that it takes ~83 times more energy to melt 1 kg of ice than to increase temperature of 1 kg of water by 1 degree Celcius. Once summer ice is nearly gone, that fact alone will change summer temperature in the Arctic dramatically - big-time extra heat which so far mostly goes into melting sea ice will instead start to increase temperatures of ocean waters and adjacent athmosphere, with above mentioned consequences.