ISLAMABAD              -            A squad of climate-related factors is responsible for the massive Australian coral bleaching event of 2016. If we’re counting culprits: it’s two by sea, one by land. First, El Niño brought warmer water to the Coral Sea in 2016, threatening Australia’s Great Barrier Reef’s corals. Long-term global warming meant even more heat in the region, according to a new CIRES assessment.

And in a final blow that year, a terrestrial heatwave swept over the coast, blanketing the reef system well into the winter, Karnauskas found. The final toll: more than half the coral in some parts of the Great Barrier Reef died. “When the Great Barrier Reef bleached severely back in 2016, it earned global attention,” said Kris Karnauskas, CIRES Fellow, associate professor of atmospheric and oceanic sciences at the University of Colorado Boulder and author on the study out today (May 18, 2020) in Geophysical Research Letters. “Some speculated it was global warming, others thought it was El Niño, but the actual role of those two forces have not really been disentangled. As a physical climate scientist with a bias for the ocean, I thought I should dig in.”