Previous studies have measured ocean temperatures every year for the last few decades and have established that the oceans are warming. A new paper, “Pacific Ocean Heat Content During the Past 10,000 Years," indicates that recent warming of the oceans is occurring at a historically unprecedented rate.
The study was conducted by three researchers: Yair Rosenthal, a geologist at Rutgers, Delia Oppo, a climate scientist at Woods Hole Oceanographic Institute, and Braddock Lindsay, a geoscience researcher at Columbia University. Samples of mud containing fossils of a one-cell organism called Hyalinea balthica were collected from the ocean floor near Indonesia. According to Lindsay, “The fossils allow us to reconstruct what was going on in the ocean over time." This is because the ratio of magnesium to calcium in the shells correlates to the temperature, with the magnesium content being higher, the higher the temperature. These tiny fossils allow scientists to study ocean temperatures over thousands of years.
The team concluded that there was a warm period between 10,000 and 8,000 years ago, followed by a longer period of lower temperature, and a half-degree increase in the last 200-400 years. The scientists found that although the amount of change is not greater than some historical variations, the rate of change is unnaturally rapid.
According to a press release issued by Columbia University, “The middle depths of the Pacific Ocean have warmed 15 times faster in the last 60 years than they did during apparent natural warming cycles in the previous 10,000. “We're running this huge experiment on the oceans and there might be downstream consequences we don't appreciate right now," said Braddock Lindsay.
Further reading on climate change:
IPCC Climate Change Is "Unequivocal", Urgent Action Is Critically Needed.
Author: Jennifer Scarlott, Source: Science.
