Tiny shells hint at hidden ocean warming

Pacific waters are heating up 15 times faster than in earlier eras

By studying shells from tiny organisms found in the Flores Sea, researchers have shown that the Pacific Ocean has warmed much faster in the last few decades than it did in previous centuries.

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Calcium and magnesium in the shells of single-celled, bottom-dwelling creatures have given scientists evidence that the middle depths of the Pacific Ocean warmed 15 times faster in the last 60 years than they did in the previous 10,000 years during natural warming cycles.

Reporting the result October 31 in Science, researchers argue that the faster warming of the water could indicate that the oceans are absorbing some of the excess heat humans have created through industrial processes, which have contributed to global climate change.

The heat absorption of the oceans could explain the recent decrease in the rate of global warming in Earth’s atmosphere, which the United Nations’ Intergovernmental Panel on Climate Change noted in its September 2013 report. The oceans will not be able to absorb excess heat forever, the authors of the new study caution.

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.