Of course it matters to Mother Earth. Deeply. Haven't you heard of extinction? Not to mention all the suffering (and I'm not talking about just H. sapiens suffering)...
Species got extinct all the time on mother earth. I meant "mother earth" more as a general place for organisms to be able to live on, and we had that since a couple of hundred million years now, where the earth saw all kinds of different climates and species. Of course, many species died out during this, and others evolved. But for that system in general, climate change will not matter (as something will live somewhere, even if it warmed 10 degrees).
But our human species could not preserve the same standard of living, when such changes are too fast and to severe. Because we have big cities where they are now, we have our country-borders, our agricultural areas, areas with ethnic groups etc. If half of Europe or North America would be covered by glaciers again, and that would happen in 100-200 years, that would be catastrophic in the same way as warming. Because you have only a few decades to rebuild whole countries elsewhere, that costs huge amounts of money. And at that elsewhere there are already people living, probably not so happy, to share their land with foreign people from elsewhere leading to all sorts of ethnic and societal conflicts up to wars, which will further make it more different to deal with that situation (one has only to look at the refugee crisis or other things now, which are on a way smaller scale).
So, that was now totally off topic with regards to the 2017 melting season.
But to get back at least in the direction of the topic:
All that I wanted to say is: The past doesnt matter so much as the present. We live now and we have to deal now with climate change. And the development of sea ice plays a huge role in that, alone because of the albedo effects that an ice-free arctic in summer would have. And how 2017 will turn out, is IMO not clear at all. I would neither rule out the possibility, that the melting will slow down and we end up like 2016, or that melting will continue at a high level and we will end up lower than 2012. There are hints and arguments for both of that scenarios, and I am not confident at all, which of the paths it will take.