Ocean heat and different observation years in one report

Source publication: 2026-03-23

WMO’s 2025 climate summary reports record ocean heat content for 2025 and greenhouse-gas concentrations for 2024. A single report can contain indicators whose most recent observation years differ.

Ocean heat content describes accumulated energy. It is not interchangeable with a surface temperature or a single air-temperature reading.

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What would be wrong with labelling every number in this report “2025 data”?

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The summary gives greenhouse-gas concentrations for 2024 and ocean heat for 2025. Each indicator needs its own observation period. Publication in 2026 does not change either measurement year.

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