
Antarctica is a continent, bigger than Europe, North America or Australia, and as such it doesn’t just have one climate zone, but several of which 100% is frozen year round.
The contribution to global weather is actually very small, Antarctic weather keeps itself to itself most of the time, there is a much greater influence from ocean currents than from atmospheric effects. This contributes to Antarctica being so cold, as the weather goes round and round the continent rather than spilling over to lower latitudes as the arctic weather systems do.
No sea-level influence at all in other words