Far-reaching effects of Tibetan warming amplification on polar sea‑ice retreat

The polar regions are projected to warm faster than the global average, known as polar amplification, which have been extensively investigated. Warming amplification is also projected at high altitudes, particularly over the Tibetan Plateau. However, little is known about the influence of Tibetan Plateau amplification on the wider climate systems, including polar sea-ice. Here, using numerical simulations, we show Tibetan Plateau amplification accounts for ~20-30% and ~10-15% of the Arctic and Antarctic sea-ice loss, respectively, projected under a high-emission scenario. Notably, the relative contribution of Tibetan Plateau amplification to projected sea-ice loss increases with the level of global warming. For the Arctic, Tibetan Plateau amplification primarily drives sea-ice loss by enhancing northward atmospheric heat transport. For the Antarctic, a two-stage ocean-atmosphere-coupled pathway is proposed: the enhanced southward oceanic heat transport warms the southern low-to-mid-latitude sea-surface temperatures, which subsequently modify the large-scale atmospheric circulation, favorable for Antarctic warming and sea-ice loss. Tibetan Plateau warming amplification is projected to drive ~20–30% of Arctic and ~10–15% of Antarctic sea-ice loss, with its influence strengthening under higher warming levels, according to model simulations coupling atmospheric, oceanic, and sea-ice components.