In 2019, ocean temperature was the warmest it has been since scientists started keeping track in the 1950s. Researchers can find out more about our planet’s rate of global warming by measuring the increase in heat.
You should know that oceans are heat stores. They have more than 90 percent of the excess heat from human-emitted greenhouse gases accumulated within our seas. According to a new study, that recording-breaking average settles the warmest decade for global oceans.
“The world’s oceans (especially at upper 2,000 meters) in 2019 were the warmest in recorded human history.” This is what an international team from 11 institutes worldwide wrote in the journal Advances in Atmospheric Sciences.
The ocean heat can be compared to the Hiroshima atom bomb
As a result, those average 2019 ocean temperatures were about 0.075 degrees Celsius above the average between 1981 and 2010. Maybe this does not seem too much, but it means the ocean has taken in 228 sextillion joules of heat.
Furthermore, lead author Lijing Cheng compared the ocean heat to the Hiroshima atom bomb. It exploded with an energy of about 63,000,000,000,000 Joules. Around 3.6 billion Hiroshima atom-bomb explosions have been added to the world’s seas in the last century.
“That’s a lot of zeros indeed,” Lijing Cheng added in a press release. “The heat we have put in oceans in the past 25 years equals to 3.6 billion Hiroshima atom-bomb explosions.”
His team compared ocean temperatures between two periods of time: 1987 and 2019 to 1955 and 1986. The results showed that the rate of warming increased by a factor of 4.5. This increase means harsh storms, uncommon sea-level rise, and the death of marine animals.
Under those circumstances, the Atlantic Ocean and Southern Ocean show one of the largest warming trends compared to other oceans. The Southern Ocean is a crucial point of rising heat, with 35 to 43 percent of the global increase.
Major consequences for all of the marine ecosystems
“The overall ocean warming means the natural variability creates hot spots and marine heatwaves,” said Cheng. “The Blob was a notable one in 2014. It led to major consequences for all of the marine ecosystems, from plankton to fish to marine mammals and birds.
Over 100 million cod were lost. A substantial marine heatwave with similar consequences for marine life occurred in the south Tasman Sea in 2015.”
Cheng’s team obtained their data from the Institute of Atmospheric Physics ocean analysis. IAP uses a method to account for scattered values and updates in the instruments used to analyze ocean temperature.
They calculated ocean temperatures down to 2,000 meters using observations from a variety of measurement instruments. The researchers took the data from the World Ocean Database of the National Oceanic and Atmospheric Administration.
Ocean warming consequences
“It has lots of consequences: it melts ice sheets from the bottom because of ocean warming, bleaching coral reefs. Ocean warming rises sea level, fuels the storms, reduces the ocean dissolved oxygen, and increases extremes like marine heatwaves.
These stresses caused by ocean environmental changes pose high risks to biodiversity and fisheries, and cause economic losses,” Cheng said.
After all, it is important to note that ocean warming will still go on. Greenhouse gas emissions are responsible for changes in ocean temperature emissions that are slow to respond and equilibrate.
Nevertheless, the rates can become smaller with lower greenhouse gas emissions. But there is still hope. “The rate of increase can be reduced by appropriate human actions. They lead to rapid reductions in GHG emissions, reducing the risks to humans and other life on Earth.”