It would have been unthinkable not many years ago to imagine the impending death of the Great Barrier Reef. The world’s largest living structure and a world heritage site unsurpassed for its tremendous beauty, the Great Barrier Reef has been one of the planet’s most important ecosystems. Now, after consecutive years of prolonged, extreme marine heatwaves in 2016 and 2017, one-half of the reef is dead.
Yet the reef, which has gone through immense challenges over millions of years of changing climates, is not entirely gone yet. Leading coral reef scientist Terry Hughes recently told the Guardian that, “The Great Barrier Reef is certainly threatened by climate change, but it is not doomed if we deal very quickly with greenhouse gas emissions. Our study shows that coral reefs are already shifting radically in response to unprecedented heatwaves.”
Further work from other research teams documented in April that globally, marine heatwaves have increased in frequency and are of longer duration. Scientists from the Australian Research Council’s Centre of Excellence for Climate Extremes and the Institute of Marine and Antarctic Studies published a study finding that between 1925 and 2016, marine heatwaves occurred 34 percent more often, and lasted 17 percent longer. The result has been a 54 percent increase in the number of marine heatwave days happening each year globally.
The study brought together a range of ocean temperature data over the time period studied. Controlling for climate variability, the authors were able to determine that the increase in marine heatwaves was related to an increase in sea surface temperature. “With more than 90 percent of the heat…