Deep blue carbon
The ocean stores more than 85 per cent of all carbon on Earth.  
Yet, ocean carbon is mostly missing in climate forecasts and climate mitigation strategies – threatening our ability to achieve net zero.

About deep blue carbon

The ocean is the most important global carbon storage depot on Earth.

The coastal ecosystems characterized by mangroves, seagrasses, and seaweed known as blue carbon or coastal blue carbon ecosystems perform important functions preserving biodiversity, supporting coastal blue economies, and locking down millennia of carbon stored as root systems and sediments.

However, most ocean carbon is found seaward of these ecosystems, in deeper continental shelf waters and off the shelf in the high seas. This deep blue carbon includes carbon contained in the waters themselves, the plankton they contain, and the sea floor beneath them. Between them, coastal blue carbon and deep blue carbon amount to almost 90% of all global carbon stores (see figure below).  Annually, it’s the flux of CO2 into deep blue carbon that results in 95% of the ocean’s carbon uptake. To date, the ocean has taken up 40% of human fossil fuel emissions.

But this carbon absorption function is changing – and how fast is becoming increasingly uncertain. The ocean is critically under-observed.

Figure illustrating carbon reservoir by size of which the ocean comprises 88% of all reservoirs
Carbon Reservoir by Size

Why it matters for our climate

Climate is at the top of the international policy agenda: 137 nations have committed to global net zero targets.  Climate change has been identified as the number one risk to global businesses, overtaking geopolitical, cyber, and pandemic risks.

To succeed in creating robust climate policies and credible targets, nations must be able to rely on the accuracy of the predicted climate trajectory. The lack of ocean data is undermining our ability to predict long-term climate change and weather events.

The Ocean Frontier Institute (OFI) is calling on nations  to provide the necessary investments and coordination for comprehensive ocean observation. The risk to our economy and our planet is too great to ignore.

The need to observe: the North Atlantic Carbon Observatory

OFI is proposing the North Atlantic Carbon  Observatory (NACO) as an initial framework.

This initiative would allow nations to join forces to consider how to measure, manage, and report on carbon – enabling better climate forecasts to inform global climate policy and strategy.

OFI has researchers with the necessary expertise, leadership capabilities and credibility, and international stature, to be the catalyst and align international science and policy perspectives on ocean carbon.

Learn more about NACO

An opportunity for climate mitigation

Ocean-based CDR—commonly referred to as marine CDR (mCDR)—is a suite of methods that either amplify or accelerate the ocean’s natural biological, physical or chemical processes, to reduce carbon in the atmosphere and safely store it in the ocean.

Examples of mCDR approaches include ocean alkalinity enhancement, artificial downwelling, electrochemical techniques, ocean fertilization and artificial upwelling.

mCDR in Deep blue carbon ecosystems offers the potential to substantially narrow the necessary carbon-sequestration gaps because of the ocean’s high potential volume and durability of carbon storage (potentially 1000 – 10,000 years in the deep sea).   Estimates of the cumulative potential for deep blue carbon sequestration vary significantly – ranging from conservative estimates of around 1Gt/year CO2 to a theoretical cap of multiple Gt/year CO2.

While accelerated and scaled research with field trials is required to better understand and quantify its impact, deep blue carbon offers other strategic advantages, such as limited land-use conflicts, being more equitable for developing nations, and potential for greater economies of scale.