The Heat
Ocean Heat Records
| Metric | Value | Context |
|---|---|---|
| Heat absorbed (2025) | 23 zettajoules | 39× total human energy production |
| Record streak | 9 consecutive years | Highest ocean heat content |
| SST 2024 | 15.10°C global average | 0.12°C above 2023 record |
| 2023–2024 SST jump | +0.25°C | 1-in-512-year extreme |
| Deep ocean warming | 36 terawatts | Irreversible on human timescales |
4th Global Coral Bleaching Event (2024)
| Metric | Value |
|---|---|
| Reefs impacted | 84% worldwide |
| Ocean species dependent on reefs | 25% |
| Reef ecosystem services | $375 billion/year |
| Recovery time if lost | Thousands of years |
Marine Heatwaves
In 2023, 96% of the world’s oceans experienced at least one marine heatwave. Average duration has quadrupled to
120 days. The North Atlantic heatwave persisted for 525 days at 3°C above normal — reshaping ecosystems and fisheries across the basin.
AMOC Warning
The Atlantic Meridional Overturning Circulation has been declining since the 1990s. 44 climate scientists published an open letter warning that collapse risk is “greatly underestimated.” A shutdown would devastate Nordic climate, disrupt monsoon systems, and alter weather patterns worldwide.
Ocean Carbon Sink Failing
The ocean’s ability to absorb our emissions is weakening — a
15% decrease in uptake sensitivity over 20 years. More than 70 scientists from 21 countries confirm the trend: the very buffer that has shielded us from the full force of climate change is failing.
Sources
- WMO — 2025 Was One of Warmest Years
- Eos — 2025 Ocean Heat Content Record
- NOAA Coral Reef Watch
- Science — Record Marine Heatwaves 2023
- Nature — Record SST Jump 2023–2024
- Nature — AMOC Warning of Collapse
- Science Advances — AMOC Tipping Course
- Columbia — Ocean Carbon Sink Ailing
- NOAA Climate.gov — Ocean Heat Content