The year 2025 was the warmest on record for the heat content of the world’s oceans. Ocean heat content (OHC) increased by around 500 zettajoules – billion trillion joules – since the 1940s.

Extreme heat, droughts, storms and deadly floods challenged resilience not only in Australia, but across the globe.

This level of warming will increase climate risks, especially for vulnerable societies. Although the average temperature over the next five years is likely to exceed 1.5°C above pre-industrial levels ...