The amount of human-made heat energy absorbed by the world’s oceans has doubled since 1997. According a study released Monday, the world’s oceans absorbed approximately 150 Zettajoules of energy in the 132 years from 1865 to 1997, and then they absorbed another 150 Zettajoules of energy in the 18 years from 1998 to 2016.
A Joule is the unit of electrical energy equal to the work done when a current of one ampere is passed through a resistance of one ohm for one second .A Zettajoule is one sextillion Joules. That’s the 150 Joules followed by 21 zeros (150,000,000,000,000,000,000,000 Joules). That is a lot of energy; almost too much energy to comprehend.
The Associated Press report on the study explained it this way. If you were to explode one atomic bomb every second for a year, and each of those A-bombs was the size of the bomb that was dropped on Hiroshima in 1945, the total energy released by all those atomic bombs would only be 2 Zettajoules. So since 1997, the Earth’s oceans have absorbed human-made heat energy equivalent to exploding a Hiroshima-style A-bomb every second for 75 straight years.
The study, Industrial-era global ocean heat uptake doubles in recent decades, was published in the journal Nature Climate Change. The research is probably the most comprehensive study ever made of ocean temperatures.
The science of Oceanography dates back to the four year long voyage of British research ship HMS Challenger (1872 to 1876). The scientists who did the new research not only used ocean-observation data that dates back to the HMS Challenger voyage but also included data from modern high -tech underwater monitors and computer models to track how much human-made heat has been captured in the oceans during the past 150 years.
Scientists have known for years that the vast majority of the heat energy from human-made global warming goes into the world’s oceans and not into the ground. And in recent years they have noticed that ocean heat content rise in recent years. Most of the added heat has been trapped in the upper 2,300 feet, but with every year the deeper oceans also are absorbing more energy.
Paul Durack, an oceanographer at the Lawrence Livermore National Lab in California, and a co-author of the study said, “The changes we’re talking about, they are really, really big numbers. They are nonhuman numbers. After 2000 in particular the rate of change is really starting to ramp up,”
The scientists who participated in the study examined, “OHC (ocean heat content) changes in the context of the Earth’s global energy budget since early in the industrial era (circa 1865–2015) for a range of depths. We rely on OHC change estimates from a diverse collection of measurement systems including data from the nineteenth-century Challenger expedition, a multi-decadal record of ship-based in situ mostly upper-ocean measurements, the more recent near-global Argo floats profiling to intermediate (2,000m) depths, and full-depth repeated transoceanic sections. We show that the multi-model mean constructed from the current generation of historically forced climate models is consistent with the OHC changes from this diverse collection of observational systems. Our model-based analysis suggests that nearly half of the industrial-era increases in global OHC have occurred in recent decades, with over a third of the accumulated heat occurring below 700m and steadily rising.”