Ocean : Powerful climate regulator

The oceans, whether it is the Atlantic, of the Pacific, of the Indian, from the Arctic or Antarctica, play an essential role in climate regulation. When the Earth warms, oceans store most of the heat, thus fulfilling a crucial function in climate regulation.

The global ocean, which encompasses the five oceans, acts as the Earth's climate regulator and thermostat. It is therefore essential to study the ocean to better understand and anticipate climate variations.. The water in the oceans is much denser than air and has a heat capacity four times greater than that of air.. The oceans are the main reservoir of heat on the planet, absorbent 90 % excess heat induced by climate change. It is important to note that in recent decades, they have slowed the rate of human-caused climate change by capturing approximately 30 % anthropogenic carbon dioxide emissions.

According to the explanations of Casimir Yélognissè Da-Allada, oceanographer and teacher-researcher at UNSTIM, the ocean constitutes an immense thermal reservoir a thousand times greater than that of the atmosphere, by storing heat received from the sun. “Tropical regions receive more heat than other regions of the globe, because they are vertical to the sun. By transporting heat accumulated in tropical regions by surface ocean currents to polar regions, the ocean interacts with the atmosphere and thus contributes to making the planet habitable”, he hammers. Casimir Yélognissè Da-Allada teaches us that the ocean plays an essential role in the complex mechanisms that govern the climate. “This is also why, in the context of global warming, the study of the relationships between the ocean and the climate has become more than ever a major scientific issue for oceanographic researchers like us”, he continues. " Today, we talk about the blue planet because in reality, almost ¾ of the total surface area of ​​planet Earth is made up of water spaces such as seas, oceans, rivers, rivers, marigots, etc. You should know that these vast expanses of water are home to hundreds of thousands of phytoplankton”, makes the climate change specialist understand, Junias Azondjinmon. " The 70 % of the surface area of ​​planet Earth is made up of oceans, what is today our greatest savior, because it is thanks to all the plants, mainly phytoplankton present in ocean ecosystems and their capacity to absorb CO2 through the process of photosynthesis, that human beings and even animals will be able to survive with the temperature on the Earth's surface", he explains.

The climate change specialist agrees with the oceanographer to say that “the ocean regulates the climate through several processes., the most important of which is the absorption of CO2 by phytoplankton, which are small microscopic algae residing in the oceans. These phytoplankton capture CO2 and transform it into biological oxygen, then into dioxygen O2, which is released into the atmosphere ». According to these explanations, phytoplankton absorb almost 50 % carbon dioxide contained in the atmosphere, much more than all the forests on earth. Junias Azondjinmon explains that phytoplankton have a very high CO2 sequestration power. “Studies have revealed that the ocean absorbs more than a quarter of the anthropogenic CO2 emitted each year”, did he know. According to Casimir Yélognissè Da-Allada, the ocean has two major mechanisms for removing carbon from the atmosphere. This is the physical pump operated by ocean circulation and the biological pump through photosynthesis.. On his side, Junias AZONDJINMON explains that thanks to the circulation of water, thermal exchanges occur, which helps regulate the temperature of the atmosphere.

Regulatory but dangerous sometimes

The essential role of the ocean in climate regulation via CO2 capture benefits existing ecosystems, especially plants. However, this regulation presents a risk for marine fauna which can sometimes adapt or migrate in reaction to pronounced variations in the pH of its habitat. This results in the disappearance of certain fish populations..

The climate change specialist, Junias Azondjinmon, makes it known that if phytoplankton cannot capture ultraviolet rays, there will be no photosynthesis. Or, without this photosynthesis, phytoplanktons cannot survive, which weakens the food availability of several fish species that feed on phytoplankton. “CO2 gradually dissolves in water and this produces carbonic acid which reduces the pH of the water. With such situations, some species adapt to the situation, but others migrate”, did he declare. “The ocean is a natural carbon sink, but which tends to reduce due to the warming of surface waters of the oceans. This warming of the oceans causes a reduction in the production of plant plankton, phytoplankton, which consumes carbon dioxide to grow. So, the reduction in plant plankton will lead to less CO2 trapped in ocean waters and therefore the ocean will no longer be able to play its role as regulator of the CO2 level in the atmosphere.. CO2 in the ocean will cause acidification of ocean waters and thus, all marine biodiversity will be weakened”, makes the oceanographer Casimir Yelognissé understand. Several studies have revealed that from a certain altitude in the oceans, there is great heat.

We must protect the ocean to benefit from its benefits

In order to take full advantage of this noble opportunity offered by the oceans, it is imperative that we ensure their preservation. Preserving the climate essentially means adopting responsible ecological behavior. “Any human initiative contributing to reducing global warming is welcome because it is man who uses large quantities of fossil energy (oil, coal, gaz) for transport, After a mid-term evaluation in, the industry, heating or electricity and causes an additional greenhouse effect which warms the planet”, says Casimir Yelognissé. According to the oceanographer's explanations, it is the human way of life that must be reviewed to also save our oceans. “When we talk about approaches to mitigating the effects of climate change, you may have heard of the term before “Solar geoengineering”, in particular the geoengineering of stratospheric aerosols, which is one of the methods of artificially reducing the amount of sunlight reaching the earth's surface in order to cool the planet. Effectively, much work is underway to evaluate the advantages of such a technique, but also to understand the consequences of such a method on the climate”, he asserted.

Christelle Djomamou (Jupiter)