Why is carbon important to our climate?
Carbon has a major influence on our climate and is a critical building block for life. The continuing increase of carbon dioxide in our atmosphere from human activities is warming the planet, leading to impacts from sea level rise to ocean acidification.
This warming would be substantially worse without the ocean, which has absorbed over a quarter of all the extra CO₂ we've added to the atmosphere. Ocean circulation then transports this carbon away from the surface, trapping it at depth.
The Ocean and Carbon
The amount of human-caused CO₂ the Ocean absorbs.
The amount of tonnes the ocean holds of carbon.
The amount of our oxygen the ocean produces through marine life.
Deeper Knowledge of the Ocean
This warming would be substantially worse without the ocean, which has absorbed over a quarter of all the extra CO₂ we've added to the atmosphere. Ocean circulation then transports this carbon away from the surface, trapping it at depth.
The necessity of carbon for organisms to grow, whether they are bacteria or whales, means that life in the ocean provides an extra natural reservoir of carbon. Tiny plants called phytoplankton use carbon dioxide in seawater to reproduce. This carbon then passes through the food web, in some cases taking hundreds of years to reappear as dissolved carbon dioxide and re-engage with the atmosphere.
Understanding what controls the transfer of carbon dioxide from the atmosphere to the ocean is vital. It allows us to better understand historical climate and to improve predictions of future climate. These are both vital for better planning and mitigating the potential impacts of effects such as ocean acidification and sea-level rise.
Although there is currently no evidence that the storage of carbon by marine life is helping reduce anthropogenic carbon in the atmosphere, there is evidence that it can influence climate significantly on longer time scales.
With questions about the ocean's capacity to continue absorbing CO₂ from the atmosphere, some have considered directly manipulating the ocean's ecosystems and surface chemistry to address global warming. This approach is called marine carbon dioxide removal (mCDR).
Key Outcomes of Our Ocean Carbon Research
Carbon datasets that NOC routinely generates and collects directly contribute to annual international estimates of the Global Carbon Budget and assessments of the impacts of ocean acidification on the UK's coastal waters.
Professor Stephanie Henson was a lead author on the last IPCC (AR6) report on the physical science basis for climate change, lending her expertise on the role of marine life in the global carbon cycle.
NOC has developed the technology to detect the escape of carbon dioxide from undersea reservoirs, which have been proposed as a means of reducing atmospheric concentrations.
NOC recently organised and hosted the WEPAL/QUASIMEME workshop on Quality Assurance for Ocean Acidification Monitoring in March 2025. This brought together national, European, and international experts in marine carbon research to share best practice and develop new processes to ensure the highest quality datasets are being produced.
How has NOC contributed to policy development?
NOC contributed to the UK government's independent review into Greenhouse Gas Removals by:
- Providing oral evidence to the review committee in Whitehall.
- Participating in a multi-stakeholder roundtable event alongside commercial entities, regulators, and academics.
- Submitting written evidence on mCDR approaches.
What community engagement has NOC undertaken?
NOC engaged with the local community of St Ives, Cornwall, to facilitate knowledge-sharing regarding perspectives towards the potential environmental impacts of coastal mCDR approaches.
Interested in learning more about NOC's ocean carbon research or how the ocean regulates atmospheric CO₂? Connect with our research teams to explore how we're advancing understanding of the ocean's critical role in the global carbon cycle.