Deep Ocean Warming Happening at 'Alarming' and Increasingly Rapid Rate

Nearly half of the increases in ocean temperature between 1865-2015 occurred in just the past 20 years, a rate which is steadily getting quicker, a new study published Monday reveals.

Deep underwater, below 700 meters, the ocean holds 35 percent of the world’s heat associated with greenhouse gases—an increase from the 20 percent it had absorbed just two decades ago, according to the study, published in the journal Nature Climate Change. Little is known about temperature measurement at that depth, which is partially what makes the findings so distressing, the researchers said.

“In recent decades the ocean has continued to warm substantially, and with time the warming signal is reaching deeper into the ocean,” said lead author Peter Gleckler, a scientist with Lawrence Livermore National Laboratory (LLNL).

“The takeaway is that the rate, at which the global ocean is absorbing excess heat, has rapidly increased—so that in more recent times since 1997, it has absorbed as much heat as it took over 100 [years] to absorb,” Gleckler said. “That is alarming.”

Gregory Johnson, a researcher with the National Oceanic and Atmospheric Administration (NOAA), added, “Given the importance of the ocean warming signal for understanding our changing climate, it is high time to measure the global ocean systematically from the surface to the ocean floor.”