The World Meteorological Organization's State of the Climate in the South-West Pacific 2026 report, released earlier this year, contains the data that anchors much of the Pacific climate-mobility story. The numbers warrant a brief, dedicated piece because they establish the baseline that other regional reporting rests on.
Sea level in the South-West Pacific is rising at approximately 4.52 millimetres per year, measured across the WMO's network of regional tide gauges and verified against satellite altimetry. The global average for the same period is approximately 3.4 millimetres per year. The Pacific is therefore rising at roughly 33% above the global mean — and within the Pacific the variation is significant, with some sub-regions measuring closer to 5 millimetres per year.
Sea-surface temperatures in the same region have risen at approximately three times the global average rate since 1980. Marine heatwaves in the South-West Pacific have approximately doubled in frequency since the same baseline year, and their average duration has lengthened. The combination of higher mean temperatures and more frequent heatwaves is the mechanism producing the coral bleaching reported in Edition 001 — the fourth global bleaching event, which entered the Pacific in 2024 and remains active.
The reason these numbers matter is that the Pacific climate-mobility story — the Tuvalu policy launch, the Vanuatu UN resolution, the Marshall Islands adaptation work, the regional discussions of relocation frameworks — rests on the assumption that the rates of change in the region are real and continuing. The WMO data establishes that they are. The 4.52-millimetre rate is not a projection. It is a measurement.