Climate change’s unyielding impact: report warns of dire consequences for global ecosystems

WEB DESK: Rising sea levels, propelled by climate change, pose an escalating and unstoppable threat, with regional effects entangled with seasonal variations.

A recent report by Dr Hirotada Moki and the Coastal and Estuarine Environment Group at Japan’s National Institute of Maritime, Port and Aviation Technology (NIMPAT) delves into the estimated repercussions of this phenomenon on vital ecosystems such as coral reefs, tidal marshes, and mangroves worldwide.

Speaking via video conference, Dr Moki and his team predict a catastrophic loss of up to three-quarters of the world’s coral habitat, including the iconic Great Barrier Reef.

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Additionally, blue carbon sinks, represented by tidal marshes and mangroves, face potential reductions of about 92 per cent and 74 per cent, respectively.

These ecosystems play a pivotal role in carbon storage and climate mitigation. The International Union for the Conservation of Nature highlights that 83 per cent of global carbon circulates through oceans, with half of it sequestered in coastal habitats covering a mere 2 per cent of the total ocean area.

Coastal ecosystems, including seagrass meadows, are essential ‘blue carbon’ stores, locking up carbon in coastal and marine habitats.

While coral reefs don’t store blue carbon due to the release of carbon dioxide in the formation of their skeletons, they contribute significantly to the global economy, generating an annual astonishing $34 billion despite covering only 0.2 per cent of the seafloor, according to Dr Manuel Gonzalez-Rivero from the Australian Institute of Marine Science.

Coral reefs support over 25 per cent of the world’s marine biodiversity and provide essential services to more than a billion people, including coastal protection, fisheries, medicine sources, recreation, and tourism.

The report explores two scenarios, ‘representative concentration pathways’ (RCPs), to project the future of these ecosystems.

The best-case scenario, RCP2.6, involves comprehensive strategies recommended by the scientific community to curb emissions, shift to renewables, and promote sustainable practices.

The worst-case scenario, RCP8.5, predicts a grim future with increased sea levels and temperatures, almost double the critical threshold of 2oC.

Under RCP8.5, the report indicates potential global coral habitat shrinkage of up to 74 per cent by 2100, and tidal marshes and mangroves could dwindle by 91.9 per cent and 74.3 per cent, respectively.

Dr Moki acknowledges the imperfections in models and emphasises the need for considering potential effects of ocean acidification on marine organisms, which the current model did not include.

As sea-level rise impacts become a stark reality, communities and nations face immediate threats.

Dr Gonzalez-Rivero emphasises that the impacts of coral reef degradation could be felt much earlier than 2100, especially in vulnerable regions relying on these ecosystems.

For instance, Tuvalu, a nation battling coastal erosion, saltwater intrusion, and diseases due to sea-level rise, stands as a poignant example.

The study concludes by highlighting the urgency of prompt and targeted action, centered on reducing greenhouse emissions, to address the critical perspective it brings to the forefront.”