Global ocean temperatures break records for sixth year in a row

The water temperature in the upper layers of the world’s oceans is breaking records for the sixth year in a row. Scientists believe that the growing heat content of the ocean is the leading indicator of anthropogenic climate change.

Experts from China and the US have published a report on ocean surface temperature trends over the past 70 years. In 2021, another temperature record was recorded, for the sixth time in a row.

According to climate models, the energy contribution from the greenhouse effect is a maximum of two watts per square meter. At first glance, the value is negligible. But if you multiply this figure by the ocean’s surface area, this is 361 million square kilometers. Additionally, the heat capacity of water is more than four times the heat capacity of air.

As a result, since the middle of the last century, the surface of the oceans has warmed by 0.8 degrees. The climate response is already being felt. The ocean in the climate system is the main and most efficient heat accumulator. In a sense, it plays the role of a time bomb – a meager but long-term pumping of energy into huge reserves of water can lead to irreversible consequences.

Suffice it to note that the heat content of only four meters of the ocean is close to the heat content of the entire Earth’s atmosphere. The circulation system of mass, heat, and salt in the whole thickness of the oceans is called the global conveyor. It is arranged so warm and salty water from the southern latitudes sinks in the subarctic under lighter freshwater. This process is mainly active in the North Atlantic.

And suppose this water is one to one and a half degrees warmer. In that case, the heat reserves in the thickness of the Arctic seas are growing – this is an additional and compelling factor in the reduction of sea ice.

In the tropics, an increase in ocean surface temperature inevitably leads to an increase in the frequency of floods and hurricanes.