Belém90% of excess planetary heat enters the ocean.
The UNFCCC has no ocean metrics in national reports and no systematic integration into Global Stocktake assessments — a structural gap, not a knowledge one, researchers argue.
Embedding ocean indicators before COP31 is the minimum needed for climate plans to track cascading marine risks.
Sources: Nature
WHERE THE HEAT GOES
The ocean has absorbed roughly 90% of the excess heat trapped by greenhouse gases since 1970. The atmosphere gets the headlines, but it holds barely 1% of the imbalance — water has a thousand times the heat capacity of air per unit volume.
HOW WE KNOW
Two independent measurement systems converge on the same number: CERES satellites measure the radiation imbalance at the top of the atmosphere, and the Argo float array — about 4,000 autonomous probes — measures ocean heat content from below. When both agree, confidence is high.
THE UNFCCC ARCHITECTURE
The 1992 Framework Convention built reporting around national emissions inventories: each state tallies its CO2, methane, and land-use fluxes. Ocean heat content, marine heatwave days, and sea-level rise sit outside this accounting because they aren't national — they belong to a shared fluid that ignores borders.
THE GLOBAL STOCKTAKE
Paris replaced binding targets with a five-yearly Global Stocktake — a collective audit of whether national pledges add up to 1.5°C. The Stocktake's inputs are the metrics states report. Anything not in the reporting template is invisible to the audit by design.
WHY OCEANS GOT LEFT OUT
At Rio in 1992, ocean science was thinner: Argo didn't deploy until 2000, and marine heatwaves weren't formally defined as a category until 2016. The UNFCCC architecture froze around the metrics that existed at signing — adding new ones requires consensus from 198 parties, which is why structural gaps persist for decades.
WHAT MARINE HEATWAVES DO
A marine heatwave is five or more consecutive days above the 90th percentile of local sea-surface temperature. The 2013-16 'Blob' in the northeast Pacific killed a million seabirds, collapsed cod stocks, and shut down Dungeness crab fisheries. These events are doubling in frequency per decade.