Removing CO2 from the atmosphere and the Desarc-Maresanus project

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Milan, 4 February 2020 – One year after the launch of the “Desarc-Maresanus” research project run by Politecnico di Milano and the Euro-Mediterranean Centre on Climate Change with the support of Amundi and the collaboration of CO2APPS, the main results were presented at a conference on the 4th and 5th of February, where various technological solutions for removing CO2 from the atmosphere were also discussed.

Desarc-Maresanus” studied an alkalinization process to simultaneously address two environmental problems of enormous concern: the increase of the concentration of carbon dioxide (CO2) in the atmosphere and the resulting acidification of the oceans. The process involves spreading calcium hydroxide on the surface of the sea, which would increase the seawater’s capacity to provide a buffer to the acidity, halting the dangerous decrease of pH. This, in turn, can foster an additional removal of CO2 from the atmosphere, generating negative emissions. More specifically, a detailed analysis was done of the technical and economic feasibility of this process, its environmental balance, and the benefits for the marine sector, focussing on the Mediterranean basin.


The main points addressed by the Desarc-Maresanus research project are the following:

  • A modeling study showed how spreading calcium hydroxide on the surface of the sea would make it possible to counteract the existing trend of acidification of the Mediterranean, which is currently in line with what is happening in the oceans worldwide. The calcium hydroxide combines with water and the dissolved CO2, which increases the seawater’s capacity to act as a buffer against the acidification, while making it possible to counteract the decrease of pH.
  • The dispersion of calcium hydroxide in a liquid suspension after its release from a ship was studied using a fluid dynamic model. This has shown the feasibility of dispersing large quantities, thanks to the great turbulence caused by the propeller and by the ship’s wake.
  • Various calcium hydroxide dispersion scenarios were studied for the Mediterranean Sea, considering various types of ships, and the potential for dispersion on a global scale based on current maritime traffic was evaluated. Dispersion by existing ships on their commercial routes has proven to be the most efficient solution.
  • Innovative systems were studied for storing the additional CO2 generated by the process, in order to allow the generation of negative emissions. They include the storage in the deep sea in the form of bicarbonates, or directly inside glass capsules. Detailed simulations of the latter were done to evaluate their mechanical strength. The conditions that could make the various options more or less advantageous were discussed, in relation to the local context, as well as indications for further research needed to ensure that the potential environmental impacts are reduced to a minimum.
  • The capital and operational costs of the new process were assessed and are competitive with the expected price of CO2 on the carbon market envisaged for the coming decades, following a serious implementation of a carbon tax.
  • The overall process was also evaluated with a life-cycle assessment (LCA), that has given encouraging results for different variations of the process based on different types of fuels. Various range of benefits, drawbacks, and technological challenges are present, that must be tackled with future research.

According to Prof. Stefano Caserini, Professor of Mitigation of Climate Change at Politecnico di Milano and Project Leader for the research: “The results attained are very interesting and are another step forward, making us confident that it is possible to remove CO2 from the atmosphere at prices that are not prohibitive, while also providing an answer to the great problem of acidification of the sea. More research is required, on both the technological process and interactions with the environment, but these initial results are promising. We know that we need to reduce greenhouse gas emissions quickly and drastically, and with this project we have begun to work on doing even more”.

Prof. Mario Grosso, Scientific Coordinator of the Research for Politecnico di Milano, added: “The time has come to propose something really ambitious to combat climate change and the acidification of the oceans. The encouraging results of this project come at the most favourable time, precisely when we are entering the decisive decade for dealing with these epochal challenges, and when the European Union is also proposing strong, concrete mitigating strategies”.

Dr. Simona Masina, Director of the Ocean Modelling Division at the Euro-Mediterranean Centre on Climate Change Foundation, stated: “As has been pointed out in the latest IPCC reports as well, simply reducing CO2 emissions will not suffice for combating the climate crisis on our planet. The modeling studies done in Desarc-Maresanus research project indicate how an adequately sized alkalinization process could contribute to simultaneously mitigating the two main problems caused by high anthropogenic CO2 emissions: global warming and acidification of the ocean”.

Paolo Proli, Head of Retail Distribution di Amundi SGR, concluded: “Once again in 2020 we have renewed our economic support to the Desarc-Maresanus research project, because attention to the questions of sustainability and combating climate change is one of Amundi’s long-term commitments, that cannot stop at a single initiative, but permeates deeply into our Company – from investment, to voting policies at shareholders meetings, and initiatives in favor of the environment, with a social impact”.

Project website:

About Amundi

Amundi is the leading European Asset Manager in terms of masses managed1, and one of the top 10 worldwide1. Via its six main investment centres2, Amundi manages Euro 1,563 billion3 in assets.

Amundi offers its clients in Europe, the Asia-Pacific Region, the Middle East, and North and South America, access to distinctive skills on the financial markets, as well as a complete range of active, passive, and real asset investment solutions. Its clients also have access to a complete range of services and tools. With its head office in Paris, Amundi has been quoted on the Stock Exchange since November 2015.

Thanks to its distinctive research and skills of a team of almost 4,500 professionals and experts in the market located in 37 countries, Amundi offers private, institutional, and corporate clients with innovative investment strategies and tailor-made solutions for their needs, profitability goals, and risk profiles.

Amundi. Confidence must be earned.

For further information or to find the nearest Amundi team, go to the website

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[1] Source: IPE “Top 400 Asset Managers” published in June 2019, AUM data as at 31 December 2018

[2] Investment Centres: Boston, Dublin, London, Milan, Paris and Tokyo

[3] Amundi data as at 30 September 2019

Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC)

The Euro-Mediterranean Centre on Climate Change Foundation (CMCC) is a non-profit research institute that engages in running studies and models of our climatic system, and its interactions with society and the environment. It aims to guarantee reliable, timeous, and rigorous results, in order to stimulate sustainable growth, protect the environment and, in the context of climate change, develop adaptation and mitigation policies based on scientific knowledge.

The CMCC’s research organisation – with branches and offices in Lecce, Bologna, Capua, Milan, Sassari, Venice, and Viterbo – involves mainly public, but also private, institutions that collaborate in multidisciplinary activities and investigations into questions related to climate change sciences.

The CMCC’s scientific activities are broken down into eight research divisions, which share various skills and knowledge sets in the field of climate sciences:

ASC – Advanced Scientific Computing; CSP – Climate Simulations and Predictions; ECIP – Economic analysis of Climate Impacts and Policy; IAFES – Impacts on Agriculture, Forests and Ecosystem Services; ODA – Ocean modelling and Data Assimilation; OPA – Ocean Predictions and Applications; RAAS – Risk Assessment and Adaptation Strategies; SEME – Sustainable Earth Modelling Economics.

Further information at:

Politecnico di Milano

Politecnico di Milano is one of the most prestigious technological universities in the world.

According to the QS World University Rankings 2020 it is one of the top 150 universities in the world, and has retained its first place in Italy for the fifth year in a row.

It was founded in 1863 and is the largest school of architecture, design, and engineering in Italy, with six campuses located in the regions of Lombardy and Emilia Romagna.

Thanks to its strong internationalisation policy, many courses are held entirely in English. This attracts an ever-growing number of international students, coming from more than 100 different countries: in the 2018/2019 academic year, 27% of all students registered for Laurea Magistrale [Master of Science] courses were of foreign origin.

Strategic research is carried out mainly in the fields of energy, transport, planning, management, design, mathematics, and natural and applies sciences, ICT, built-up environments, and cultural heritage, with more than 250 laboratories.

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