Ocean temperatures continued to rise in the year 2020, despite the COVID-19-induced lockdowns and subsequent travel and work restrictions, says a new study.?
It reports the highest ocean temperatures since 1955 from surface level to a depth of 2,000 meters.
Published recently in the journal Advances in Atmospheric Sciences, the study has been authored by 20 scientists from 13 institutes across the world. The observation in the study concludes with a plea to global policymakers and all to consider the impending disastrous effects of climate change in their actions.
"Over 90% of the excess heat due to global warming is absorbed by the oceans, so ocean warming is a direct indicator of global warming -- the warming we have measured paints a picture of long-term global warming," said Lijing Cheng, lead author of the paper and associate professor with the Chinese Academy of Sciences (CAS).
The scientists at the CAS used an indigenous method to calculate the ocean temperatures and salinity of the oceans to a depth of 2,000 meters from the surface. They took the required data from ¡°all available observations from various measurement devices from the World Ocean Database,¡± highlights a EurekaAlert report.
The scientists discovered that the upper 2,000 meters of the world's oceans absorbed 20 more ZettaJoules of heat in 2020 than the previous year. The report mentions that this amount of heat is enough to boil ¡°1.3 billion kettles, each containing 1.5 liters of water.¡±
"Why is the ocean not boiling?" Cheng said. "Because the ocean is vast. We can imagine how much energy the ocean can absorb and contain, and, when it's released slowly, how big the impact is."
In their study, the researchers report several effects of ocean warming. These include amplification of the ocean salinity pattern as well as an increase in division among the upper and the lower layers of the ocean.
"The fresh gets fresher; the salty gets saltier," Cheng said. "The ocean takes a large amount of global warming heat, buffering global warming. However, the associated ocean changes also pose a severe risk to human and natural systems."
Apart from the ecosystems being altered directly by the heating of the oceans, the researchers warn that these have extended climatic effects too. Cheng cited the examples of 2020 wildfires in Australia, Amazon, as well as the west coast of the United States.
"Warmer oceans and a warmer atmosphere and also promote more intense rainfalls in all storms, and especially hurricanes, increasing the risk of flooding," Cheng said. "Extreme fires like those witnessed in 2020 will become even more common in the future. Warmer oceans also make storms more powerful, particularly typhoons and hurricanes."
Cheng called for a serious acknowledgement of the issue to safeguard the planet¡¯s future. "Any activities or agreements to address global warming must be coupled with the understanding that the ocean has already absorbed an immense amount of heat and will continue to absorb excess energy in the Earth's system until atmospheric carbon levels are significantly lowered," Cheng said.