A recent study by Cheng et al has found that the world’s ocean is warming 13% faster than we previously thought. This new study corrected observed temperatures for known errors to gain a better agreement between Argo profiling floats and shipboard measurements in conjunction with new spatial interpolation techniques. This allowed the researchers to gain a more comprehensive and more accurate measure of the rate at which the ocean is warming.
The ocean has absorbed more than 90% of the excess heat associated with increasing greenhouse gasses, much of it in the surface ocean. The ocean has been warming rapidly over the last 60 years (the length time that we at least partial temperature measurements across most of the ocean basins), and the rate of warming is roughly twice as fast after 1992, with measurable warming reaching depths of 700 meters.
While the impacts of this warming are not fully understood, the warming of the oceans in general is not favourable for the Pacific islands. We are still in the midst of a global coral bleaching event that is driven by elevated ocean temperatures, and has led to severe bleaching of more than 70% of the Great Barrier Reef in Australia. There is a lack of coral bleaching data in the Pacific islands, but the impacts here are likely comparable. Prolonged bleaching can lead to coral mortality, with recovery times taking five years or more.
Sea surface temperature anomaly (difference between the current sea surface temperature and the long-term average) for the Pacific Ocean. Exceptional warming is occurring in the south central Pacific (red colors), and cooler than average temperatures are occurring in the western equatorial Pacific (blue colors). Image courtesy of NOAA Coral Reef Watch (https://coralreefwatch.noaa.gov)
For more information contact: Tommy Moore, SPREP’s Pacific Islands Global Ocean Observing System (PI-GOOS) Officer ([email protected]).
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