“In the face of inaction, coral reefs will soon disappear,” Leticia Carvalho, head of UNEP’s Marine and Freshwater Branch said on Monday 21 December. “Humanity must act with evidence-based urgency, ambition and innovation to change the trajectory for this ecosystem, which is the canary in the coalmine for climate’s impact on oceans, before it’s too late.”
Coral reefs are incredibly important and sustain a wide variety of marine life. They also protect coastlines from erosions from waves and storms, sink carbon and nitrogen and help recycle nutrients. Their loss would have devastating consequences not only for marine life, but also for over a billion people globally who benefit directly or indirectly from them.
Coral bleaching
When water temperatures rise, corals expel the vibrant microscopic algae living in their tissues. This phenomenon is called coral bleaching. Though bleached corals are still alive and can recover their algae, if conditions improve. However, the loss puts them under increased stressed, and if the bleaching persists, the corals die.
The last global bleaching event started in 2014 and extended well into 2017. It spread across the Pacific, Indian and Atlantic oceans, and was the longest, most pervasive and destructive coral bleaching incident ever recorded.
In its report Projections of Future Coral Bleaching Conditions, UNEP outlines the links between coral bleaching and climate change. It postulates two possible scenarios: a “worst-case scenario” of the world economy heavily driven by fossil fuels; and a “middle-of-the-road” wherein countries exceed their current pledges to limit carbon emissions by 50 per cent.
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Posted On: 05/01/2021