Mangroves provide a unique habitat to many species and are important to the well-being of many local communities. However, they are disappearing rapidly because of overexploitation, pollution, and development. According to UNESCO, currently three-quarters of mangroves worldwide are under threat.
Now, a new study shows that the destruction of mangrove forests could lead to a 50,000% increase in carbon emissions by 2100.
Mangrove forests, which cover approximately 0.1% of the Earth's land, store a significant amount of carbon, particularly in their soils. However, human development in these areas has led to the reduction in these carbon stocks, a press statement by IOS Publishing explained. This has specifically affected regions such as southern India, southeastern China, Singapore, and eastern Australia.
The study, published in Environmental Research Letters, shows that over the past two decades, a huge number of mangrove forests have been replaced by agriculture, aquaculture and urban land management. This has caused the global mangrove carbon stocks to reduce by 158.4 million tons, the statement elaborated.
The findings showed that when population density reaches 300 people/km2, the carbon stored in mangrove soils near populated areas is estimated to be 37% lower than isolated mangrove forests. Furthermore, the annual rate of carbon emissions from mangrove loss is currently estimated to be 7.0 Teragrams, consistently rising with increased population density to 3,392 Teragrams by current predictions at the end of the century.
In the statement, lead author Jennifer Krumins says this study emphasizes the importance of protecting mangroves, specifically those in areas with high population density. “Mangrove forests are critical to the regulation of carbon sequestration, and it is important that we protect them. The first step is to understand the impact of human populations and activities on mangrove forest carbon stocks,” Krumins adds.
The ability of mangrove forests to store significant amounts of carbon could also help countries achieve their carbon emission reduction goals under the Paris Agreement. Mangrove soils can store three to four times the mass of carbon typically found in tropical forests. However, their rapid decline has been a concern and there is a need for their protection as well as restoration to be prioritised.
