In the fight against change climaticin recent years has purchased growing attention the Blue Carbonor Blue carbonthat is, that portion of carbon subtracted from the atmosphere aside ecosystems Mariniin particular from coastal vegetable habitats such as swamps brackish, meadow of Fanserogame marine And forests Of mangrove. Experts estimate that, every year, these ecosystems, while occupying less than 1% of the global surface, are able to remove up to 70 million tons of carbonwhich is then stored in the long term in the sediments of the seabed, rich in organic matters. However, the degradation and the loss of these environments can have the opposite effect, transforming them from tanks into real springs carbon.
What is the Blue Carbon
The Blue Carbon It is carbon captured by marine ecosystems and stored in the biomassboth alive and dead, as well as in organic compounds within the sediments on the seabed. In particular, they distinguish themselves ecosystems coastal – like mangrove forests, brackish swamps and fans of Fanserogame – e ecosystems oceanicin which the capture of co2 is linked to the activity of the forests of algae, barriers coral of molluscs as well as various animals, from krill to whale.
In recent years, however, the blue carbon coastal has attracted attention not only of the scientific community, but also of numerous associations and countries engaged in mitigation of change climatic. In fact, it is estimated that the soils and vegetation of coastal ecosystems contain between 10 and 24 billion tons of carbon and that every year they remove from the atmosphere between 30 and 70 million tons carbon dioxide.
This figure might seem negligible if compared to beyond 37 trillion of co tons of co2 directly dissolved in the oceans or beyond 860 billion tons of carbon stored in the forests global. However, compared to forests that occupy over 30% of the emerged lands and about 9% of the global surface of the planet, coastal vegetable habitats cover less than 0.5% of the seabed and are responsible for beyond 50% of all carbon storage in sediments.
It therefore appears evident that the potential of seizure of CO₂ of these ecosystems is particularly high. Every year, a square meter of Fanserogame Marine prairie removes approximately 220 grams carbon from the atmospherewhich are subsequently buried in the sediment. It is a value more than three times higher than the storage rate of one square meter of tropical rainforest, more than seven times that of temperate forests and over ten times that of large grasslands.
How blue carbon storage takes place
When it comes to carbon storage in coastal ecosystems, we usually refer to brackish swamps, mangrove forests and gray grasslands marine, ecosystems characterized by the predominant presence of vegetation.
- The brackish swampsalso known as coastal savory swamps or tidal swamps, develop in the basementan area of transition between the mainland and the sea, and host a dense vegetation composed of herbsaromatic plants, shrubs and other species alophiteThat is, adapted to living in high salinity environments.
- The mangrove They are trees and shrubs adapted to thriving in brackish environments and are mainly found in tropical and subtropical regions, in countries such as Indonesia, Thailand and Mexico.
- The meadow of Fanserogame marine (Seagrass Bed) are ecosystems made up of higher flower plants, such as the note Posidonia oceanicawhich colonize the sandy or muddy backdrops of the coastal areas with depths between 0.5 And 40 meters.
All types of vegetation subtract co2 from the atmosphere through the photosynthesisusing it not only to produce your own nourishmentbut also to form the fabrics. The carbon thus captured is stored in roots, stems And leaves. Upon the death of plants, the degradation processes of organic matter tend to free carbon dioxide again. However, in a marine environment, where oxygen levels are lower, the decomposition takes place more slowly and much of the organic matter remains trapped within the sediments. For this reason, if undisturbed, marine soils can retain carbon for centuries or even millennia.
Experts estimate that they are already stored in the first meter of sediment 28 kg c/m² (kilograms of carbon on a square meter) in mangrove forests, 25 kg c/m² in the tidal swamps e 14 kg c/m² in the grasslands of Fanserogame Marine.
The consequence of the loss of marine ecosystems
The reverse of the Blue Carbon medal and the extraordinary storage capacity of the coastal ecosystems is that, if degraded or destroyed, they are transformed tanks to Carbon sourcesrapidly releasing in the atmosphere what has been accumulated over the centuries. According to a 2012 study published in the magazine Plosone, the loss of coastal ecosystems could increase of 19% the current estimates of carbon emissions caused by deforestation.
Experts estimate that every year they disappear on average almost 700,000 hectares of marine ecosystemsdue to both climate change and human activities. Over the past two centuries, about the 67% of the global mangrove coverage, the 35% of the tidal swamps and the 29% of the meadows of Fanserogame Marine. Numerous countries have already implemented actions aimed at safeguarding and restoring the Blue Carbon coastal ecosystems and these have already started to perform the function of tanks. In particular, it has been demonstrated how the meadows of Fanserogame Marine begin to effectively seize co2 atmospheric within four years from the restoration.
In addition to the capture of carbon, coastal ecosystems guarantee numerous other ecological benefits. Offer habitat essential For fish, reptiles, mammals and many other organisms, they contribute to stabilize the coasts and play a crucial role in the prevention ofcoastal erosion.
