A new study has found that the world’s oceans were the hottest in 2019 than any other time in recorded human history, especially between the surface and a depth of 2,000 metres.
The results were published alongside a call to action from the authors for humans to work harder to reverse the negative impacts climate change. The report also outlines that global ocean temperature is not only increasing, but also speeding up.
“It is critical to understand how fast things are changing,” said John Abraham, co-author and professor of mechanical engineering at the University of St. Thomas in the United States. “The key to answering this question is in the oceans – that’s where the vast majority of heat ends up. If you want to understand global warming, you have to measure ocean warming.”
The researchers examined newly available data as part of the study, which allowed them to examine warmth trends dating back to the 1950s. This study also includes ocean temperature changes recorded by NOAA. The two independent data sets indicate that the past five years have been the warmest on record for global ocean temperatures. The team also compared the 1987 to 2019 data recording period to the 1955 to 1986 period. They found that over the past six decades, the more recent warming was ~450% that of the earlier warming, reflecting a major increase in the rate of global climate change.
They concluded that the 2019 ocean temperature was about 0.075 degrees Celsius above the 1981-2010 average. To reach this temperature, the ocean would have taken in 228,000,000,000,000,000,000,000 (228 Sextillion) Joules of heat.
“That’s a lot of zeros indeed. To make it easier to understand, I did a calculation. The Hiroshima atom-bomb exploded with an energy of about 63,000,000,000,000 Joules. The amount of heat we have put in the world’s oceans in the past 25 years equals to 3.6 billion Hiroshima atom-bomb explosions.” said Lijing Cheng, lead paper author and associate professor with the International Centre for Climate and Environmental Sciences at the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences (CAS). “This measured ocean warming is irrefutable and is further proof of global warming. There are no reasonable alternatives aside from the human emissions of heat trapping gases to explain this heating.”
The researchers have added their voices to a now common line of hope echoed around the scientific community – that humans can work to reverse their effect on the climate but we need to act now. They state that the ocean will take longer to respond to positive change than atmospheric and land environments. Since 1970, more than 90% of global warming heat went into the ocean, while less than 4% of the heat warmed the atmosphere and land where humans live.
“Global warming is real, and it’s getting worse,” Abraham added. “And this is just the tip of the iceberg for what is to come. Fortunately, we can do something about it: We can use energy more wisely and we can diversify our energy sources. We have the power to reduce this problem.”
To read the full paper, Record-Setting Ocean Warmth Continued in 2019, click here.
Photograph by Francesco Ungaro.
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