Anyone thinking 2012 has been the absolutely worst, may be dropping their jaws this summer.
Given just the preconditioning last summer & especially this winter and all the unprecedently high, relentless dmi temp anomalies things are set up for possible worst case scenario.
One, that has none regard whatsoever for U.S. elections, individual future carreer plans etc...
I think this year will beat 2012, mostly because I look more at feedback effects - beating records now has albedo effects that only help build momentum, etc. (Though I think you meant 2016 in your first line).
I don't have a way to quantify it, though; how much extra heat does this lesser extent allow the arctic to absorb from insolation, and on what scale is that compared to say, extra atmospheric heat pumped by the dipole anomaly, or heat pumped from currents, or the Mackenzie/Ob/etc?
My main concern with this year and the "general climate impact" has been... what happens when the ice is (mostly) gone? So far the arctic and to a lesser extent the world ocean is like a glass of ice water. Putting a hot torch on it melts more of the ice, but it still stays at its triple point of roughly 0C... as long as there's some ice. Whether the ice is 10 cm or 10m thick, it's the same temperature for the overall system... until it all melts.
If that happens though, I think there would suddenly be a lot of very noticeable knock-on effects. For instance an arctic entering the freezing season at 4C with no ice would freeze a lot less new ice and have much less brine rejection (since it has to cool to below 0 C before it can start making new ice). The extra heat would relentlessly pound the greenland ice cap (which is otherwise stuck at 0C). The atmosphere would absorb a lot more moisture from the ocean surface directly. Thermohaline circulation as we now know it wouldn't be a little different; it'd go haywire. Could we get lake effect snows from the Hudson Bay? What does that moisture mean downstream?
None of those things can happen in the current regime; whether we have an extent minimum of 4Mkm^2 or 8Mkm^2, the amount of freezing in the winter has been (historically, though not this pyear) about the same, and even greater than usual in some years (like 2012).
That could change - and we could have a substantial discontinuity in effects for northern hemisphere climate