When Will Antarctica’s Snow Melt? Projections: Centuries, But Coastal Loss Accelerating

No precise date exists. Antarctic ice loss is a gradual, non-linear process driven by competing forces. Current science:

1. Coastal & Peninsula Melt (Now – 2100)

• West Antarctica & Antarctic Peninsula: Rapid ice shelf collapse (Larsen A/B, Wilkins), glacier acceleration (Thwaites “Doomsday Glacier”).
• Contribution to sea-level rise: ~0.4 mm/yr now; could reach several mm/yr by 2100 (IPCC AR6).
• Marine Ice Sheet Instability (MISI): Grounding lines on retrograde beds → self-sustaining retreat.

2. Ice Sheet Mass Balance

• Net loss: ~150 Gt/yr (1992–2020 avg), accelerating.
• East Antarctica: Near balance/slight gain (increased snowfall) – but vulnerable basins (Totten, Cook) waking up.

3. Long-Term Projections (2100–2300+)

4. “Complete Melt” Timeline

• Total ice volume: ~26.5M km³ (58 m sea-level equivalent).
• Full melt: Millennia even under extreme warming – ice sheet inertia is massive.
• Irreversible commitment: Some sectors (WAIS) may already be committed to multi-meter loss over centuries.

5. Wild Cards

• Hydrofracturing (meltwater splitting ice shelves).
• Subglacial hydrology changes.
• Bedrock rebound (isostatic adjustment) – may slow or accelerate retreat.
• Geoengineering (marine cloud brightening, seabed curtains) – speculative.

Bottom Line

Coastal Antarctica is melting now. Interior ice sheet persists for centuries. The rate depends on our emissions this decade. Every 0.1°C matters.