The consequences of global warming are harmful to all forms of life, both terrestrial andaquatic. Recently, researchers revealed that marine coral reefs are at risk of disappearing despite the provisions of the Paris agreement on the climate. Focusing on aquatic vegetation and fauna, their study also revealed the impact of this threat on human activities.
According to scientists, the ambient temperature can increase by 1.5°C compared to that of the pre-industrial era. As a result, it has been mentioned that a multitude of coral reefs in the world will not be able to withstand the strong heat waves marines. If the temperature rises by 2°C, the proportion of dead coral reefs will increase to 100%.
However, scientist Adele Dixon pointed out that the rise in climate cannot be without danger to corals. For her, a rise of 1.5°C still represents warming too high for these fundamental marine ecosystems.
The Paris Convention is not enough!
At the end of this convention dating from 2015, the member countries decided to limit global warming to 2°C. However, storms, floods, dry waves have been more deadly than before and the temperature remained stable at 1.1°C. As a result, nations have committed to limiting global warming to 1.5°C, which corresponds to a major ambition of the agreement.
In a new report, the IPCC, the United Nations climate science expert group, has announced that the 1.5°C threshold could be reached from 2030. In the course of 2018, this group predicted the disappearance of 70-90% coral reefs if the 1.5°C threshold were reached. This proportion would increase to 99% in the event of additional rise temperature of 0.5°C.
Marine heat waves leading to their disappearance
In reality, seawater absorbs 93% excess heat produced by greenhouse gases. They thus protect the mainland, but cause large sea heat waves. persistent. This situation leads to the gradual disappearance corals, which have already exceeded their tolerance threshold.
So the main danger comes from ocean heat waves and how long it takes for coral reefs to recover. This recovery step is called “thermal shelters”.
“It usually takes 10 years for corals to recover, provided certain factors (lack of heavy fishing or pollution, for example) are favorable. »
Maria Beger, study scientist
In addition to their contribution to the maintenance of aquatic ecosystems, corals provide protein, income and protection against bad weather and coastal degradation. Thus, their disappearance will impact the lives of thousands of people in the world.
SOURCE: SCIENCE NEWS