Climate change is a major threat to coral reefs around the world. Ocean warming triggers coral bleaching – a stress response where corals expel the symbiotic algae essential for their survival. If coral bleaching is severe, it can lead to coral death.
A new study led by scientists from Newcastle University in England suggests that corals are unlikely to adapt to ocean warming quickly enough to keep pace with global warming, unless there are rapid reductions in global greenhouse gas emissions.
The study, which was recently published in the journal Science, found that coral heat tolerance adaptation via natural selection could keep pace with ocean warming, but only if the climate goals of the Paris Agreement are realized. In the Paris Agreement, countries agreed to limit global warming by the end of the century to two degrees Celsius above pre-industrial levels.
However, current climate policies around the world have the globe on track to warm by three degrees Celsius. According to the research team, this could lead to significant reductions in reef health, elevated risks of local coral extinctions, and considerable uncertainty in the so-called “evolvability” of corals.
Coral reefs are among the most biologically diverse ecosystems on Earth. They are often referred to as the “rainforests of the sea” because they support an incredible variety of marine life. They provide essential ecosystem services, such as protecting coastlines from erosion and storm surges, supporting fisheries, and serving as a source of income through tourism. Coral reef health is vital for the health of the planet.
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Coral adaptation unlikely to keep pace with global warming
Photo, posted June 9, 2012, courtesy of Bokissa Private Island Resort via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio