High-Temperature Coral Bleaching in Australia’s Great Barrier Reef during 2024, 2020, and 2017: A Statistical Modeling Approach

Earlier this year, Australia’s Great Barrier Reef cooked at temperatures higher than any it has experienced in at least four centuries, according to climate researchers. The finding — which they published today in Nature1 and attribute to human-induced climate change — comes as scientists rush to understand the impacts of the most intense and extensive coral-bleaching event ever recorded for the 2,300-kilometre reef system.

OVe Hoegh-Guldberg is a professor of marine studies and co-author of a book on the Great Barrier Reef. It is very worrying that we are close to this point and I believe it will happen in the next 10 years. While corals can survive bleaching, reefs generally need one or two decades to recover from severe mass bleaching, according to the related article.

Corals have skeletons of calcium carbonate that form reefs. The skeletons of corals that can grow for centuries allowed Henley and his coauthors to look into the past. Scientists can study like tree rings as they grow as they form bands. There are signatures that show the heat stress in certain years. The ratio of strontium to calcium and the oxygen isotope ratio in particular relate to the temperature of the water at the time the corals were still growing.

There isn’t consistent data on sea surface temperatures from direct measurements prior to 1900. But the researchers were able to combine what data was available from direct measurements with data from skeleton core samples to build a statistical model that they then used to reconstruct temperatures going back to the 1600s. They focused on temperatures between January and March when waters surrounding Australia’s Great Barrier Reef tend to be the hottest.

That’s how they discovered that those periods in 2024, 2020, and 2017 reached the highest temperatures in four centuries. It has been 1.73 degrees Celsius above the average between 1618 and 1899.

The Great Barrier Reef in a state of flux: evidence from AIMS’s latest tropical bleaching event on 7 August 2015 is encouraging news for corals

Corals are often bleached when they are stressed out by high temperatures, because they expel the colourfulalga that live inside them and provide them with energy through photosynthesis. Depending on the severity and duration of the bleaching event, the corals might recover, or they might die, threatening the biodiverse ecosystems that provide habitat for fisheries, attract tourists and protect coastlines from storms.

Policies currently in place to slash greenhouse gas emissions from fossil fuels still aren’t enough to stop things from getting much worse. Global average temperatures are on track to rise between 2 and 3 degrees Celsius, which is higher than before the industrial revolution. Previous research has estimated that even a two-degree rise could be enough to wipe out 99 percent of the world’s coral reefs.

If we’re going to keep it going, we need to believe in it. If we protect coral reefs with the right amount of action on greenhouse gasses then we can set them up for a future.

The researchers think the evidence may eventually force the United Nations cultural organization to re-think their decision not to include the Great Barrier Reef in their World Heritage sites list.

The study arrives at nearly the same time as the Australian Institute of Marine Science (AIMS) in Townsville issues its latest report on the state of the Great Barrier Reef, including data from both aerial and underwater surveys of corals conducted since a massive bleaching event earlier this year. That analysis, released on 7 August, includes some encouraging news: many areas of the reef have bounced back since 2016, when a major bleaching event led to widespread coral mortality.

A Game Theoretic Approach to Biodiversity: The case of Kaluza-Klein, Max Kozlov and the Nature Podcast

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The refrain “Publish or Perish”, which means publications are the core currency of a scientist’s career, can now be found in a new board game. Created as a way to help researchers “bond over shared trauma”, the game features many mishaps familiar to academics, scrambles for funding and scathing comments, all while players must compete to get the most citations on their publications. Reporter Max Kozlov set out to avoid perishing and published his way to a story about the game for the Nature Podcast.

A study shows that the plants are more diverse in dry environments. Trait diversity is a measure of an organism’s performance in an environment and can include things like the size of a plant or its photosynthetic rate. There are good data on diversity in the tropics, but there is not an assessment of drylands. This knowledge gap was filled by the new study that shows that trait diversity increases when there is a certain level of aridity. The team behind the work hopes that they can help protect biodiversity as the planet warms.