Page 60 - Livre_MOW2024_EN

58 | SUPPORTING INNOVATION

Are certain areas of the ocean better suited to
this solution?
Ideally, the water being enriched with these alkaline
materials should stay on the surface as long as
possible to give the ocean time to absorb CO
2
from the atmosphere and store it in a chemically
neutral form. If alkaline materials are added in an
area where the surface water immediately sinks
Jean-Pierre Gattuso Ocean alkalinity enhancement seems to be deep into the ocean, it won’t be in contact with the
CNRS Senior Research Scientist gaining ground. Is it a type of geoengineering? atmosphere and will be unable to absorb CO . So
2
at Villefranche Oceanography Some people class it as geoengineering; others the area needs to be carefully chosen.
Laboratory, an elected member limit that term to solar radiation modification. Don’t
of the European Academy of forget that we’ve been doing what can be described Have studies been conducted to assess the
Sciences and co-author of as geoengineering since the Industrial Revolution: impact on marine ecosystems?
several IPCC reports. He also
edited and co-authored the we take fossil carbon out of the earth and put it into There’s a lot of uncertainty around the carbon
‘Guide to Best Practices in the atmosphere, totally deregulating our climate. footprint of this solution and the impact of introducing
Ocean Alkalinity Enhancement We’re conducting a geoengineering experiment on huge quantities of alkaline materials on marine
Research’, published during COP a planetary scale. organisms and ecosystems. At the moment impact
28 in Dubai in November 2023. studies are conducted in the laboratory, sometimes
The effectiveness of alkalinity enhancement using so-called ‘mesocosms’, essentially tanks
remains unproven, but it involves adding an placed on the ground or giant test tubes deployed
antacid to seawater for two reasons: to counteract in the ocean. So far no negative impacts have been
acidification and boost the ocean’s capacity to found, but the first papers on the consequences for
absorb CO without increasing its acidity. It speeds marine life were published in 2023. It’s too early to
2
up the natural process that sequesters CO away draw conclusions.
2
from the atmosphere for 8,000 to 10,000 years.
That process is reproduced by dissolving an And unfortunately not enough laboratories are
alkaline substance, such as limestone or olivine, investigating the subject. There are no research
into seawater to enable it to store large quantities programmes in France, for example, just one in
of CO long term and in a chemically neutral form. Germany and several in America. Many more
2
start-ups have entered the field, attracted by the
These alkaline substances can be added in the prospect of selling carbon credits, and are studying
form of mineral powders extracted from rocks and and developing solutions. Scientists are a little
shipped to targeted areas of the ocean. They can concerned that research is lagging behind private
also be added as liquids (sodium carbonate, sodium industry, when it should be the other way around!
hydroxide or magnesium hydroxide), discharged We should first establish that these solutions
either off the coast or further out at sea from a boat. actually work and don’t harm living organisms before
moving on to trials and large-scale implementation.
But there is no supervision at all. It’s almost the Wild
West.