The deep seabed, an ally of the climate

Mining the deep seabed means tampering with the climate.

Nodules polymétalliques

The deep seabed is a hot topic in the news, and one that is receiving more and more media coverage. In fact, in 2024, discussions will resume within the International Seabed Authority (ISA) and decisions are imminent on the mining of its resources against a backdrop of tension over the availability of the minerals needed for the energy transition.

Scientists are warning of the consequences that mineral extraction would have on deep-sea biodiversity and on the ability of these deep-sea environments to regulate the climate. 

Did you know that the ocean absorbs 30% of the carbon emitted by human activities and that the abyss is a “carbon sink”? 

We’re going to take a closer look at the role of the deep ocean in regulating the climate.

The ocean regulates the climate 

The ocean covers 71% of the planet and determines the climatic conditions that prevail on the Earth’s surface. The ocean has absorbed approximately 90% of the heat and 30% of the CO2 emitted into the atmosphere by human activities. 

By absorbing and storing the primary greenhouse gas, the ocean plays a fundamental role in regulating the climate.  

The deep seabed is a carbon sink

CO2 is transferred from the atmosphere to the oceans by two mechanisms. The first is called the “physical pump”: 90% of absorption takes place when cold water sinks to the high latitudes, carrying dissolved CO2 with it to the seabed. 

The second mechanism, called the “biological pump”, involves living organisms. Phytoplankton algae bind CO2 through the process of photosynthesis. Once dead, the phytoplankton sinks to the bottom where some of the carbon it contains is trapped in mineral form in marine sediments for centuries.

Therefore, the deep seabed is a CO2 “sink”.

One in every 2 breaths we take comes from the ocean 

This is a matter of fact. When you breathe, half of the oxygen that fills up your lungs comes from the ocean!
And this oxygen is produced by ocean plant plankton, which binds CO2 through the process of photosynthesis.

What impact would deep-sea mining have on the climate? 

•    Extracting minerals using machines that dig into the ocean floor could release the carbon and methane trapped in the sediments and disrupt the ocean’s carbon sequestration role.
•    Mining would also have consequences for deep-sea biodiversity, and a study published by Ifremer in Nature Communications shows the contribution of plumes to “carbon assimilation rates in the deep ocean. In fact, the micro-organisms living in hydrothermal plumes “transform around 3% of the total organic carbon dissolved in water into what is known as particulate carbon”.

 

 

Photo : Ifremer

We must join forces to protect the deep seabed!

Nausicaá endorses France’s position against deep-sea mining and will use every means at its disposal to raise awareness and mobilise as many people as possible in support of a moratorium.

Abyss

Pacifique SW_Ifremer

The deep seabed: its future is still unc...

Abyss 5mn

The future of the deep seabed at stake at the ISA: moratoriu...

Deep-sea mining: what impact will it hav...

Abyss 4mn

The treasures of the abyss are attracting a great deal of in...

crevette rimicaris Ifremer abysses

14 things you just have to know about th...

Abyss 7mn

Find out more about what lies beneath the surface, all the w...

Exploring the abyss: a new adventure dow...

Abyss 5mn

New underwater technologies for deep-sea exploration.

Méduse de profondeur NOOA

Geography of the abyss: what does the de...

Abyss 3mn

Can you imagine that beneath the surface of the ocean, there...

coraux des abysses Ifremer

The deep seabed, a hostile and uncharted...

Abyss 4mn

Total darkness, pressure and cold: extreme conditions to exp...

Bioluminescence: why do the animals in t...

Abyss 6mn

Bioluminescence, an example of how life has adapted to condi...

Humpback anglerfish

Abyss 2mn

You've heard of it, haven't you? Undoubtedly yes if you have...

Why are we talking about the abyss?

Abyss 3mn

The abyss is a mysterious environment because it is largely ...