“We are losing our oceans”: historic temperature records in 2021

2021 will not be remembered as the hottest year on record. Not in the atmosphere at least. But in the oceans, a completely different scenario is playing out. The researchers confirm to us today that they were, last year, warmer than ever.

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In 2021, the temperatures of our atmosphere have not reached new record (fifth place of the warmest years). The European climate change monitoring service, known as Copernicus, confirmed this yesterday. On the other hand, data released today by the Chinese Academy of Sciences and the United States Oceanic and Atmospheric Observation Agency (NOAA) show that our oceans were, last year — and for the sixth consecutive year — warmer than ever. At a depth between 150 and 450 meters, the average ocean temperature reached 14.4°C. It was 13.8°C in 2000!

Bad news, because remember that the content of heat of the oceans is a major indicator of the anthropogenic global warming. The seas, in fact, absorb a large amount of the excess heat present in our atmosphere. Over 90%.

Researchers now show that in 2021, the oceans, in their upper 2,000 meters, have thus absorbed at least 14 zettajoules — or 1021 joules — more than in 2020 — and even up to 227 zettajoules more than the average for the period 1981-2010. To give you a better idea, know that in one year, all of the human activities on the Planet consume one energy about… half a zettajoule!

Another consequence of anthropogenic greenhouse gas emissions

Thus no natural variation of type The boy Where The girl cannot be held primarily responsible. These variations, in fact, mainly affect temperatures on a regional level and over a relatively short period. And in addition to its magnitude, this warming can be measured everywhere in the world.

In addition, researchers tell us that the oceans have been warming significantly and continuously since the end of the 1960s. But that since the late 1980s, their temperature has risen at a rate up to six times that of previous decades. And it is certain regions of the Atlantic Ocean, the Pacific Ocean and the Indian Ocean that appear to be the most affected.

Bad news for the planet

By absorbing so much heat, the ocean gets into trouble. Its water is warming. With consequences on its properties and on its dynamics. On his volume, for example. Because when its temperature rises, water expands. Result, the sea ​​level mounted. When the oceans warm up, its exchanges with the atmosphere are also modified. And with them, the cycles of precipitation and finally, the frequencies and intensities of extreme weather events.

Another worrying element highlighted by the researchers: with its warming, the ocean is losing its ability to absorb carbon dioxide (CO2) of the atmosphere. So he leaves more in theair than previously. A kind of vicious circle. And a better understanding of this heat/carbon coupling phenomenon could therefore prove crucial in the near future. Even if it seems more obvious than ever that until we reach the goal of zero emissions clear, the oceans, too, will inexorably continue to warm.

Record temperature for the oceans in 2020

We are used to evaluating the global warming to the increase in the temperature of our atmosphere. But researchers are now reminding us that the world’s oceans are also warming. In 2020, they reached a record temperature.

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Article of Nathalie Mayer published on 01/13/2021

In 2020, the CO rate2 in the air have further increased. Temperatures have soared. Including those of the ocean, confirms to us today a study carried out by a international team of researchers. Between the surface and a depth of 2,000 meters, never since 1955, the average temperatures of the ocean had been so high as during the course of last year.

Based on measurements present in a database world, researchers have calculated that in 2020 the oceans absorbed 20 zettajoules (ZJ) – or 20×1021 joules – more than in 2019. An amount of heat that would be enough to boil 1.3 billion kettles each containing 1.5 liters of water! Note, however, that while the US Agency for Oceanic and Atmospheric Observation (NOAA) comes to the same conclusion of an increase in ocean temperature since 2019, its figures are more moderate – only 1 ZJ of additional heat absorbed. All of this confirming an underlying trend.

Don’t overlook the importance of the ocean

Fortunately, the ocean is vast. It does not boil. By absorbing a large amount – researchers speak of 90% – of excess heat, it dampens the global warming. But at what cost ? That of modifications of salinity and a stratification increased. That of a slow release of this accumulated heat also, enough to maintain the effects in the long term. Even after our CO emissions stop2.

More immediately, warmer oceans favor more intense rains, and hurricanes and more powerful typhoons. With the floods and the material and human damage that may accompany them. Hence the importance of not forgetting to consider the ocean when policies to combat global warming are put in place.

The ocean is experiencing an unprecedented rise in temperature

The report of the Intergovernmental Group of Experts on the evolution of the weather (IPCC) dedicated to the issue claims that the global ocean has been warming relentlessly since 1970. And today, data from the programme Copernicus come to clarify the question: the ocean is experiencing an unprecedented increase in temperature.

Article by Nathalie Mayer published on 11/10/2020

Each year, the Copernicus program — a European Union program for the observation and monitoring of Terre — publish a state of the ocean report of the world. It relies on satellite data, field measurements and expert analyses. The one just released reports an unprecedented rise in sea temperatures.

Between 1993 and 2018, the global sea surface temperature — one of the important measures, along with the heat content of the ocean — has increased by 0.014°C per year. The past four years appear to be the hottest on record.

Signs of major tensions on the oceans

What researchers call ocean heat content refers to the heat absorbed by the ocean. Know the amount ofthermal energy stored in the ocean is essential for understanding the state, variability and changes of the Earth’s climate system. In the last quarter of this decade, global ocean heat gain has increased in the upper 700 meters of the ocean. Heat has been trapped in deeper ocean layers, down to over 2,000 meters.

Remember that the increase in the heat content of the oceans contributes 30 to 40% of theglobal mean sea level rise, due to the dilatation thermal sea water. “More than ever, comprehensive and systematic monitoring of the oceans is needed”, note Karina von Schuckmann and Pierre-Yves Le Traon, researchers, in a statement of Taylor and Francis Group (UK). Especially since the report highlights other major tensions on the seas and oceans of the world due to the climate change, including acidification — caused byabsorption carbon dioxide (CO2) of the atmosphere –, the loss of oxygen and the retreat of sea ice. Tensions that jeopardize both the ecosystems sailors than the human societies that live off them.

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