Record heat drives coral bleaching on the Great Barrier Reef

WEB DESK: A new study found that from 2016 to 2024, the Great Barrier Reef faced severe coral bleaching linked to unusually high sea temperatures.

The research revealed that the Coral Sea experienced its warmest months from January to March in 2024, 2017, and 2020, marking the highest temperatures in 400 years.

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Marine scientist Dr Jane Smith points out that the temperature spikes were alarming because they surpassed previous records by a significant margin. The rise in sea temperatures has led to more frequent and severe coral bleaching.

Major bleaching events occurred in 2016, 2017, 2020, 2022, and 2024, with 2024 setting a new record, exceeding previous highs by 0.19°C.

Before the 1980s, coral bleaching was rare and less intense. However, in recent decades, the frequency and severity of bleaching has increased markedly. This correlates strongly with rising sea temperatures driven by global warming.

Dr Michael Brown explained that climate models attributed this warming trend to human activities. He stated that extreme temperatures cannot be explained by natural variability alone.

Historical climate models incorporating human impacts accurately reflected recent warming, whereas models excluding these factors do not.

The study analysed sea temperature data from 1618 to 2024, revealing that 2016, 2017, 2020, 2022, and 2024 were the warmest years on record. Temperatures ranged from 1.46°C to 1.73°C above pre-1900 averages.

The data showed that 2017, 2020, and 2024 were very likely to have been warmer than any year before 1900, with 2016 and 2022 also among the hottest.

While the researchers validated their methods thoroughly, some uncertainties remain due to potential data biases and the complexity of interpreting coral records.

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The findings confirmed that recent sea temperatures are the highest in centuries and that the warming trend has accelerated since the 1950s. If these trends continue, coral reefs may face annual bleaching events, which would negatively impact marine life and ecosystems.

The study used sea surface temperature data from Extended Reconstructed SST V5 (ERSSTv5) and Hadley Centre Sea Ice and Sea Surface Temperature (HadISST1.1) and coral data from various sources.