Rising sea levels are a threat not only to humans but also large carbon sinks like mangroves and marshes, according to new research. A study published in Nature on August 30th warns that rising seas will devastate coastal habitats as they do not have the capacity to cope with the sea level rises under current climate change projections. The research also uses evidence from the last Ice Age.
The study is called Widespread retreat of coastal habitat is likely at warming levels above 1.5 °C and authors are 17 institutions in Australia, Singapore, Germany, U.S., Hong Kong and the UK. They report on how coastal habitats retreated and adapted as the last Ice Age ended and how they are likely to cope with this century’s predicted sea level rises.
“Our research shows these coastal habitats like mangroves can likely adapt to some degree of rising sea levels but will reach a tipping point beyond sea-level rises triggered by more than 1.5 to 2°C of global warming… Without mitigation, relative sea-level rises under current climate change projections will exceed the capacity of coastal habitats such as mangroves and tidal marshes to adjust, leading to instability and profound changes to coastal ecosystems,” concludes the research.
Mangroves’ environmental role is critical as they act as a buffer between the ocean and the land, absorb the impact of wave action, prevent erosion, are crucial for the biodiversity of fisheries and coastal plants, and store an enormous amount of carbon dioxide, also known as blue carbon.
As the study explains, they have an in-built capacity to adapt to rising seas by accumulating sediment and moving slowly toward the land. The phase of the tide is very important to them so when they become water-logged due to higher sea levels, they start to die as the water can’t drain out properly.
“This sort of death would be devastating for many natural mangrove forests across Asia which are restricted in their capacity to retreat from rising seas due to land development and human habitation,” said lead author, coastal wetlands specialist Professor Neil Saintilan from Sydney’s Macquarie University.
“Beyond 1.5–2°C of global warming, you’ll start to see these islands disappear when the waves overtop the coral reefs that protect them,” according to co-author Associate Professor Simon Albert, The University of Queensland. Overall, in the long-term, they may not have the capacity to adapt that quickly when more land gets covered with water.
The consequences of climate change are devastating for the environment as it does not have the time to adapt to the rapid abnormalities caused by excess quantities of greenhouse gas emissions. Changes in our environment also mean changes to human lives that are entirely dependent on the health of the ecosystems, being slowly destroyed as a result of human activities.