Newswise – A multinational team of scientists (China, USA, New Zealand, Italy and France) analyzes the Earth’s temperature annually. These scientists have identified a fever that is increasing every year. For the past decade, every year the ocean has been hotter than the previous year. And there are other changes in the ocean that are also important.
The ocean is an important part of Earth’s climate system – it covers 70% of the planet and absorbs about 90% of the heat from global warming. The ocean helps control the atmosphere – a warmer ocean leads to a warmer and wetter atmosphere and wilder weather. The ocean also controls how quickly Earth’s climate changes. To know what happened or what will happen to the planet, answers can be found in the ocean.
The data were obtained from two research teams: the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences (CAS) and the National Centers for Environmental Information of the National Oceanic and Atmospheric Administration (NOAA). Based on temperature measurements analyzed by the IAP, the world ocean has warmed by 15 zettajoules compared to 2022. According to NOAA, warming was lower at 9 zettajoules. Both groups reported another year of warming, but their magnitudes differ, as discussed below. But first… what is a zettajoule? Every year, the entire globe uses around half a zettajoule of energy to power our economies. A zettajoule is a huge amount of energy. In other words: 15 zettajoules are enough to boil 2.3 billion Olympic-sized swimming pools (50 m long, 25 m wide and 2 m deep).
Why are the values different? Scientists are working hard to solve this problem, and early findings point to how each group handles the data. Big differences arise from “quality control” and the way in which individual values are mapped in a global grid. Particularly in a warming climate, new measurements of high ocean temperatures may be incorrectly dismissed.
“This means that warming could be greater than the numbers reported here.” Says Dr. Lijing Cheng from IAP/CAS, the study’s lead author.
The graphs (Fig. 1) show ocean warming since the late 1950s according to the two data sets used in the study. Both show long-term warming. When charting long-term trends, scientists choose a so-called baseline against which other values are compared. In the graphs below, the baseline is the average sea temperature over the period 1981-2010. The blue bars are colder than the 1981-2010 average – the red bars are warmer than the baseline. The top graphic shows data from IAP, while the bottom images show analysis from NOAA. The two main messages from the graphics are: There is long-term warming of the ocean due to global warming and the two groups (IAP and NOAA) agree on the long-term trends, even though a given year may be different.
Sea surface temperatures are outside the table (Fig. 2). This blowout record is caused by both long-term global warming and short-term fluctuations in water temperatures in the Pacific Ocean (El Niño). Currently, both contribute to warmer water at the ocean surface. A now-strong El Niño event in the tropical Pacific has caused sea surface temperatures to warm since May due to global warming and climate change. This, in turn, changes weather patterns around the world. Therefore, it is the relatively small natural year-to-year variation in OHC relative to the warming trend that makes OHC such a good indicator of climate change.
Precipitation and evaporation patterns also change, altering the salinity (salinity) of the oceans. Salty areas are becoming increasingly salty and fresh areas are becoming fresher, with consequences for marine life and ocean currents.
Less dense, warm and fresh water near the surface tends to stay near the surface and is unable to transport heat and carbon dioxide to deeper layers. Scientists call such water “stratified.” The newly released data shows that stratification continues to increase. This reduces the ocean’s oxygen levels and its ability to absorb carbon dioxide, with serious consequences for plant and animal life in the ocean.
A warming ocean also speeds up the weather. The additional heat and moisture released into the atmosphere lead to stronger storms with heavier rain, stronger winds, and greater flooding. There is enormous damage worldwide (approximately $200 billion per year in the United States alone), as well as major disruption and loss of life.
These findings highlight the need to immediately stop burning fossil fuels and stop releasing more carbon dioxide into the atmosphere by decarbonizing the economy and transitioning to cheaper, cleaner and renewable sources such as wind, solar and hydropower.
The final results will be published on January 11, 2024 Advances in Atmospheric Science.