LIVERMORE, Calif. – Global ocean warming has doubled over the past two decades. Scientists from the Lawrence Livermore National Laboratory in California found that over the last 18 years the oceans have absorbed as much heat as during the previous 130 years. The paper was published in Nature Climate Change and was mostly based on observation.
This accelerated absorption has contributed to keeping human habitats cooler, but the study warned that in the near future it could alter weather and climate globally. The oceans cover two thirds of Earth’s surface and have swallowed more than 90 percent of the excess heat humans have been generating with greenhouse gas emissions.
“We estimate that half of the total global ocean heat uptake since 1865 has accumulated since 1997,” reported a research team led by Peter Gleckler of the Lawrence Livermore National Laboratory.
Scientists found that a third of the latest build up occurred beyond the reach of sunlight, at depths of 700 meters or greater. According to the study, this may explain a slowdown in warming scientists detected at the sea surface since the end of the 20th century. Some experts had suggested it was a sign of a pause in warming overall, but this new study reveals that all that heat thought to have been “paused” was actually taken up by the depths of the ocean.
Should the excess heat remain in the oceans, it would have the potential to cause alterations in the sea and atmospheric circulation, profoundly disturbing weather patterns, as explained by researcher John Shepherd from the University of Southampton’s National Oceanography Center. He was not involved in the research.
If released into the atmosphere, the extra heat could remark warming that is already set to lead to severe consequences. Shepherd said the ocean cannot absorb surplus heat for an unlimited period of time.
The research team used observations from data collected in the 19th century by the HMS Challenger expedition. This is a foray released by Britain’s Royal Society that is known for being credited with laying the foundation for modern oceanography. The most recent information came from multi-decade ship logs and Argo floats scattered across the oceans.
If warming rates remain the same, Earth is on its way to reach about three degrees Celsius by the end of this century. Even an increase of 2°C could have the potential to cause tremendous natural disasters.
Humans may understand the impact of greenhouse gas emissions on the only hospitable planet they have and might truly begin taking significant action against climate change, but still the deep ocean will continue to heat up long after that because of the carbon dioxide which stays in the atmosphere for centuries.
Since the days of the Industrial Age, carbon dioxide has been causing sea water to become a quarter more acidic. To date, that acidification is at its highest level in 300 million years, hurting coral reefs and threatening other marine fauna and flora.
Source: Discovery News