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FOCUS: The millions of tonnes of 'blue carbon' in our waters... and why it matters

FOCUS: The millions of tonnes of 'blue carbon' in our waters... and why it matters

Tuesday 11 October 2022

FOCUS: The millions of tonnes of 'blue carbon' in our waters... and why it matters

Tuesday 11 October 2022

A new study has revealed the millions of tonnes of so-called 'blue carbon' locked away in Jersey's territorial waters... So what does this mean for the island's drive to net-zero?

Express dives in...

The study

The study was undertaken and published by the government’s Marine Resources team, led by Dr Paul Chambers have.

The culmination of three years of research, the resulting report offers a comprehensive look at Jersey’s marine habitats and, crucially, proposes a novel approach to Jersey’s ongoing battle with climate change and its efforts to attain carbon neutrality.

What is 'blue carbon'?

Carbon is most commonly thought of in the context of carbon dioxide, the by-product of burning fossil fuels and chief culprit of the ongoing climate crisis. 

However, carbon is essentially the building block for life and is contained within all living plants and animals. They incorporate carbon into their cells, bones and shells. As such, it is possible to offset carbon emissions by expanding key habitats for plants and animals that then absorb carbon, store it and therefore remove it from the atmosphere.

sea grass Paul Chambers.jpeg

Pictured: Dr Paul Chambers, who led the research contained in the report, examines some of Jersey's seagrass. 

The most obvious example of this, and the most prevalent in climate change discussion, concerns so called ‘green carbon’ habitats. Forests, in other words. When people talk about offsetting carbon emissions and battling climate change, reforestation is likely to be the first thing that pops into their mind. 

‘Blue carbon’, by contrast, is a relatively new area of study and has yet to enter the public consciousness to the same extent. ‘blue carbon’ habitats are effectively the marine equivalent of ‘green carbon’ ones and include ecological features like seaweed forests, seagrass meadows, mangrove swamps and saltmarshes. 

The idea then, is that just as planting trees and expanding ‘green carbon’ habitats can be used to offset carbon emissions, the same can equally be true of ‘blue carbon’ habitats. 

Jersey’s ‘blue carbon’ 

For an island such as Jersey, with an area of only 120km², the potential for ‘green carbon’ solutions to the climate crisis are limited - there can hardly be an extensive reforestation campaign in a place like Jersey.

However, Jersey’s offshore territory comprises 2,500km², 95% of its overall area, and includes large areas of marine habitat that are internationally recognised for their biodiversity and complexity.

Indeed, the results contained in the newly released report, according to Dr Paul Chambers, "suggest that Jersey’s blue carbon resources are potentially significant."


Pictured: A simplified diagram detailing the natural carbon cycle.

Specifically, the report claims that Jersey’s territorial waters contain approxiamtely 100,000 tonnes of organic carbon stored inside living plants and animals, 80,000 tonnes of carbon in Jersey’s coastal seaweeds and a further 12 million tonnes of stored inorganic carbon i.e. carbon that resides on the seabed in the form of hard shells from animals like clams, crustaceans and dolphins. 

Moreover, and most importantly, the seabed sees over 10,000 tonnes of carbon removed from the environment annually. As the report points out, this is equivalent to 8.6% of Jersey’s total emissions, based on 2019 figures. To put that into perspective, Jersey’s ‘blue carbon’ habitats potentially offset the CO² emissions of the island’s agricultural and waste management sectors combined. Moreover, Dr Chambers stressed that this is in fact a conservative estimate, with estimates lowered by as much as 20% as a result of advice gained during the peer review process undertaken by the University of St Andrews. 

Whatever the case, it seems that Jersey’s ‘blue carbon’ habitats could potentially be a huge asset to Jersey's government in their quest to see the island go carbon neutral by 2030. Indeed, ‘blue carbon’ is included in the governments carbon neutral roadmap, with the government having set themselves the goal to “continue exploring the potential for blue carbon sequestration in Jersey’s waters” by 2030. Clearly, progress on that front is already being made, as evidenced by this new report. 

Environment Minister Deputy Jonathan Renouf said: “I’m delighted to see the publication of this very timely report. 95% of the Bailiwick of Jersey is sea, and so it makes sense for us to explore what role our marine environment can play in combatting climate change.”  


Pictured: A map showing the distibution of 'blue carbon' habitats in Jersey's territorial waters. 

The market for carbon credits

Furthermore, an unexpected benefit of ‘blue carbon’ is, curiously enough, its monetary value in the form of carbon credits.

Carbon credits are a tradable commodity in which ‘credits’, each representative of 1 metric ton of carbon dioxide reduction, generated by one party may be purchased by other parties seeking to reduce their own carbon footprint.

The market for climate credits is much the same as for any other tradable commodity and therefore their price fluctuates over time in response to the laws of supply and demand. As such, Jersey could sell carbon credits from the reduction of emissions brought about by its ‘blue carbon’ habitats.

As such, the report estimates that these habitats could have a potential monetary value of between £500,000 and £1.2 million annually from the sale of credits. Clearly then, it could pay to conserve Jersey’s ‘blue carbon’ habitats.

Some hurdles

However, there are significant challenges that face this potential ‘blue carbon’ strategy. 

Firstly, there are ecological challenges facing Jersey’s seabed. 

The report provides a detailed list of potential threats that may come to plague Jersey’s marine habitats. These range from ongoing effects of climate change, such as changes in salinity and temperature, to pollution and even the introduction of invasive species. Moreover, physical damage caused by direct human interaction is also a potential hazard. The report highlights the potential damage to the seabed from Electricity cables between Jersey and France, as well as stressing the damage done by fishing vessels using trawls and dredges. It hardly needs to be said that if the seabed is destroyed, then it can be of no use in offsetting emissions. 

fishing boats protest.jpg

Pictured: Fishing, particularly using dredges and trawls, poses a potential threat to Jersey's 'blue carbon' resources.

Secondly, Jersey’s 'blue carbon' project is also faced with a problem of accreditation. The accreditation of carbon offset projects is overseen by the IPCC  - the Intergovernmental Panel on Climate Change. Because 'blue carbon' is a relatively new area of study, the IPCC has extremely restrictive guidelines on which marine habitats can actually be accredited. At present, only three kinds of marine habitat qualify for accreditation: salt marshes, mangrove swamps and sea grass.

Of the first two, Jersey has none. Of the latter, Jersey has very little. As such, Jersey would not see the benefits of accreditation under the present guidelines. However, calls have been growing for the IPCC to expand its guidelines in line with the latest research. According to Dr Chambers, this is an area “that is moving extremely fast” and so changes to the guidelines are not out of the question. 

The next step

The process to develop the potential of these 'blue carbon' habitats has already begun. In order to demonstrate the potential of Jersey's seabeds for carbon absorption to the IPCC, seabed samples need to be examined and more detailed research undertaken. The UK based Blue Marine Foundation and the University of Exeter are already beginning work on this, although it is likely that any further development will take several years. 

Furthermore, Dr Chambers was keen to stress the importance of other aspects of the report. Indeed, Chambers commented that “this report has a lot to say about our marine environment.” Indeed, the report is the first time a complete habitat map of Jersey’s maritime environment has been published and also contains crucial insights into Jersey's maritime geology.

According to Chambers, the results from this report are “very exciting” and “start to pick away at some of the extraordinary things we see in this region.”

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