“New” analysis of the 1871 GBR temperature data can be found in this file https://platogbr.com/wp-content/uploads/2025/06/gbr-paper-25-june_final_1-for-web-site.pdf

Great Barrier Reef SST Study – 200‑word Overview

This study challenges prevailing claims that sea surface temperatures (SST) on the Great Barrier Reef (GBR) have risen to unprecedented levels due to climate change. By comparing high‑quality data from an 1871 scientific expedition to contemporary measurements from the Australian Institute of Marine Science (AIMS) and the Bureau of Meteorology (BoM), the authors find no material difference in SST across the 150‑year period. Both historical and modern datasets show that maximum water temperatures in the northern GBR stabilise around 29–30 °C early in summer and do not rise further despite continued solar heating.

The study proposes that this thermal ceiling is due to powerful natural feedbacks—particularly evaporative cooling and tropical convection—which act as a climate‑regulating “ocean thermostat.” Analysis of long‑term SST records at Cape Ferguson further supports the conclusion that no significant warming trend can be attributed to anthropogenic climate forcing over the past 30 years.

Overall, the findings suggest that recent alarm over GBR warming may be overstated and that natural regulatory mechanisms are more robust than often acknowledged. This calls for a rebalancing of reef policy priorities toward direct local management rather than global climate mitigation alone.