Ocean Carbon Blind Spot May Skew Climate Forecasts

New report reveals critical lack of understanding about how the ocean absorbs and stores carbon, threatening climate predictions.

Published on Feb. 26, 2026

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A new report by the Intergovernmental Oceanographic Commission (IOC) of UNESCO reveals a critical lack of understanding of how the ocean absorbs and stores carbon. This uncertainty threatens to skew current climate predictions and hamper the development of effective mitigation and adaptation strategies. The report lays out a roadmap to bolster international cooperation, strengthen ocean carbon monitoring, and update climate models accordingly.

Why it matters

The ocean is a major carbon sink, absorbing around 25% of global CO₂ emissions. However, scientific models differ widely in estimating the ocean's carbon uptake, with discrepancies of 10-20% globally and even greater in certain regions. This means climate decisions are being made without a full understanding of how the ocean will respond to climate change, which could have major implications for emissions targets and adaptation planning.

The details

The Integrated Ocean Carbon Research Report finds that the limited availability of long-term data and gaps in understanding how key processes respond to climate change are the main sources of these uncertainties. This includes quantifying how changes in ocean warming and circulation affect carbon uptake, how shifts in plankton and microbial life influence long-term storage, and how coastal and polar regions exchange carbon with the atmosphere. Industrial activities and potential climate engineering efforts may also alter the ocean's natural carbon absorption.

  • The Integrated Ocean Carbon Research Report was published on February 26, 2026.

The players

Intergovernmental Oceanographic Commission (IOC) of UNESCO

An organization that coordinates international cooperation and research to better understand the ocean.

Khaled El-Enany

The UNESCO Director-General.

Jamie Shutler

A professor from the University of Exeter and a lead author on the new roadmap.

Ute Schuster

A lead author on the new roadmap from the University of Exeter.

Andy Watson

A professor from the University of Exeter and a lead author on the new roadmap.

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What they’re saying

“The ocean is one of our strongest climate allies, absorbing a large share of the carbon we emit. Yet we still lack a full understanding of how this natural defence functions - or how long it can endure.”

— Khaled El-Enany, UNESCO Director-General (Mirage News)

“The amount of carbon absorbed by the ocean each year is one of only two key observational constraints on global carbon assessments. Essentially, if we don't know how much carbon is going into the ocean, we can't guide governments in how to limit global heating, and we can't predict how carbon is degrading marine life which is an important source of food.”

— Jamie Shutler, Professor, University of Exeter (Mirage News)

What’s next

The report calls for a global ocean carbon observing system, combining satellites, autonomous platforms, and sustained measurements from the surface to the deep ocean. Improved ocean and climate modeling should also include stronger capacity development in under-represented regions to ensure truly global monitoring coverage.

The takeaway

This report highlights the critical need to better understand the ocean's role as a carbon sink in order to develop accurate climate models and effective mitigation and adaptation strategies. Closing these knowledge gaps through coordinated global monitoring and research is essential for guiding governments in limiting global warming.