This would effectively destroy the Reef and other shallow water reefs worldwide. Near surface waters off southeastern Australia are warming at nearly four times the global average, leading to changes in the distribution of species, species collapse and a decline in biodiversity.Ĭlimate Councillor, climate scientist and Distinguished Professor of Biology at Macquarie University, Lesley Hughes said: “Under a high emissions scenario, the Reef could face bleaching every year as soon as 2044. The briefing affirms that last year was the warmest year on record for the world’s oceans.The excess heat absorbed by the ocean in 2021 was equivalent to the energy of seven Hiroshima atomic bombs detonating every second. The reef has suffered three mass bleachings in just the past six years (2016, 2017, 2020). In recent weeks low-to-moderate bleaching has been recorded across parts of the reef. The Reef is currently being watched closely by scientists for another possible mass bleaching event, with temperatures up to 3☌ higher than average in central parts of the reef. ![]() The monitoring visit comes ahead of a World Heritage Committee meeting in June to consider listing the Reef as ‘in danger’. The Climate Council briefing, “ In hot water: Climate change, marine heatwaves and coral bleaching ” has been released today, as a UN reef monitoring delegation touches down to assess the condition of the Great Barrier Reef. I am confident could handle another 0.3C of warming, but they will struggle at 1.9C and there’s a lot of optimism in that 1.9C figure.Australia’s reefs and marine ecosystems are at grave risk of mass bleachings and extinction, a marine heatwaves research briefing from the Climate Council has found. “The higher the temperature goes, the more difficult it will be. “So far 1.1C has been sufficient to trigger five mass bleaching events,” he said. But Hughes told The Guardian that likely won’t be enough to save the Great Barrier Reef. The most recent analyses show that the promises world leaders have made so far at COP26 could put the world on track for 1.9 or 1.8 degrees Celsius of warming. One of the biggest concerns is even if we can stick to the 1.5C target, we still have committed warming.” ![]() “There are still healthy reefs producing larvae, but if we see these patterns continue you would expect it would affect rates of coral recovery. They won’t last forever,” University of Queensland Professor Peter Mumby, a co-author on the second study, told The Guardian. ![]() “We don’t yet know how long those thermal refuges will exist. These refugia could spread larvae to 58 percent of the total reef, the study found.īoth studies come as the COP26 climate conference is taking place in Glasgow, and the authors warned that protecting the reef means sticking to the most ambitious Paris agreement goal of limiting warming to 1.5 degrees above pre-industrial levels. This has made it harder for the reef to recover, but there are potential coral “refugia” in 13 percent of the reef, which have avoided temperature spikes. The last three major bleaching events may have reduced the reefs’ larvae supply by 26, 50 and 71 percent, in chronological order. Recent bleaching events occurred in 2016, 20, according to .Īnother paper also published in Current Biology Thursday shows another way in which these bleaching events have made the reef more vulnerable over time. However, the time between bleaching events has decreased, giving corals less time to recover. ![]() The researchers found that corals did have a better chance of adapting to higher temperatures if they survived a previous bleaching event, CNN explained. “Five bouts of mass bleaching since 1998 have turned the Great Barrier Reef into a checkerboard of reefs with very different recent histories, ranging from two percent of reefs that have escaped bleaching altogether, to 80 percent that have now bleached severely at least once since 2016,” Hughes told. As the climate crisis persists, marine heat waves are leading to more frequent, intense and widespread bleaching events. “This is one of the most confronting results of my career,” study lead author Terry Hughes, from the ARC Centre of Excellence for Coral Reef Studies at James Cook University, Tweeted.Ĭoral bleaching occurs when higher than average water temperatures force coral to expel the algae that provide them with nutrients and color, explained. Now, new research published in Current Biology Thursday finds that only two percent of the reef escaped some bleaching during that time. It has experienced five mass bleaching events since 1998, three of them in the last five years.
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