Apparently you don't understand the difference between seasonal sea ice and the vast continental ice sheets that are the dominant form of Antarctic ice. The evidence of accelerating Antarctic ice melt is in the graph right in front of you. Instead of continuing to misrepresent the facts, read the paper I linked. There are many others.
Maybe some basic factual exposition would be conducive to a better understanding of the subject matter here.
Fact #1: Antarctic sea ice is unimportant either as a bellweather of climate change (or of sea level rise, obviously), because the sea ice is almost entirely seasonal -- it forms in the winter and floats off northward and pretty much all melts every summer. The Antarctic is a continent surrounded by ocean where the sea ice is extremely mobile. This is the exact opposite of the Arctic which is largely ocean surrounded by land.
The important indicator of Antarctic trends is the massive continental ice sheets which are losing mass at a huge and accelerating rate. The Antarctic is also more insulated from overall planetary warming and less sensitive to climate change but that's beside the point. The Antarctic overall is losing ice mass, period. And losing it fast, at rates that are quite well quantified. Any other claim reflects either lack of knowledge or intentional deception.
Fact #2: Whether the HTM was warmer than today or not is an irrelevant red herring. If you take the average of eight major 12Ky reconstructions, it wasn't, but if you pick one you like better, you can show otherwise, with no greater or less credibility. It's ultimately completely irrelevant because the causes were completely unrelated to anything going on today and mainly based on orbitally-induced insolation changes. It also mainly affected high latitudes and had a much different distribution than contemporary warming being driven by GHG's. Some info on that here
. In fact bringing up the HTM at all is just about as pointless as bringing up the Medieval Warm Period, another denialist favourite.
When articles like the one in the OP talk about Arctic devastation from global warming being "unprecedented", I think the term could be fairly interpreted to mean "unprecedented in recorded history", and that something that happened 10,000 years ago for entirely different reasons doesn't change the validity of the statement.
Fact #3: Local and regional climate is not global climate. The fact that high-latitude insolation caused some point in Siberia to be 4 deg. warmer than today during the HTM (other Arctic areas were even warmer) or that some isolated site had a rapid temperature increase says nothing at all about the global climate. The importance of the fact that the present temperature increase is both extremely rapid and globally synchronous cannot be understated. That, and its relation to the unprecedented increases in post-industrial atmospheric CO2 is what this is all about.
Fact #4: The risks posed by anthropogenic global warming are entirely related to the stresses imposed by the extremely rapid rate of change, and little to do with long-term equilibrium points. First there are ecosystem stresses. Everything living today is adapted to its local climate, and the destabilization of ecosystem balances and adaptations can have catastrophic results and even lead to ecosystem tipping points. Second there are physical climate system stresses. Rapid changes in atmosphere and ocean circulation systems lead to weather extremes, powerful storms, long-term changes to regional climate, and general destabilization. And there, too, there is strong evidence that the earth's climate systems operate in terms of tipping points that create sudden and severe changes to large geographic areas.--
"Everyone is entitled to their own opinion, but not their own facts."
Daniel Patrick Moynihan