The world's oceans have absorbed heating equivalent to 1.5 atomic bombs per second over the past 150 years, according to new estimates.
While the world continues to emit excess greenhouse gas into the atmosphere, causing more heat to be trapped, the ocean has been dutifully doing its part by regulating the global temperature. The world's seas and oceans are absorbing 90 percent of the excess energy due to global warming, leading to increased ocean temperatures and sea level rise.
A team of scientists from the University of Oxford reconstructed the history of ocean temperature changes from 1871 to 2017. Their findings were published in the Proceedings of the National Academy of Sciences.
The Changing Temperature Of The World's Oceans
The team found that the oceans around the world have warmed 436 x 1021 Joules in the past century. The number is roughly 1,000 times the annual global human primary energy consumption.
Between 1871 to the present, the average heating of the ocean is equivalent to more than one Hiroshima-size atomic bombs per second, according to The Guardian's own estimates.
"[O]bviously, we are putting a lot of excess energy into the climate system and a lot of that ends up in the ocean," stated Laure Zanna of University of Oxford and an author of the study. "There is no doubt."
How The Past Could Predict The Future
The team believes that the reconstruction of the changes in the temperature of the ocean can help researchers predict sea level rise in the future. Surface water temperature is not uniform everywhere in the world. Ocean currents transport heat to other areas, causing sea level rise and coastal flooding.
"If we know what the sea surface temperature anomaly was in 1870 in the North Atlantic Ocean we can figure out how much it contributes to the warming in, say, the deep Indian Ocean in 2018," explained Samar Khatiwala, a professor of Earth Sciences at the University of Oxford.
Based on their calculations, the changes in the ocean circulation contributes to the warming and sea-level rise in low- and mid-latitudes of the Atlantic Ocean in the past 60 years. More heat are accumulated in the low latitudes because of the ocean circulation.
However, the researchers admit that there are certain limitations to their techniques. More work has to be done to understand changes in the ocean's circulation and predict how it will affect the future.