The surface temperature in the world’s oceans on Tuesday 5 April was 21.1 degrees on average. Figures from NOAA showed. NOAA has measured the temperatures with satellite and other measurement methods for over 40 years. Never before has the temperature been so high. – WE are entering an unknown climatic and meteorological territory that we have never been in before, says meteorologist Martin Leon to El Pais. The previous record was 21.0 degrees, set in March 2016. – It is an expected development, but it is clear that this is dramatic, says climate researcher at Cicero, Bjørn Samset. The development of the surface temperature of the world’s oceans since 1981. The thick black line shows the temperatures so far in 2023. The orange line shows 2022. Photo: University of Maine La Nina and El Nino The ocean record comes after the world has just emerged from a three-year period with the La Nina weather phenomenon. La Nina leads to low surface temperatures in the Pacific Ocean. The last La Nina was declared over in March. It is now expected that the world will eventually enter the opposite weather phenomenon, El Nino. This causes surface temperatures in the Pacific Ocean to be higher than normal. The previous heat record was set during a previous El Nino period. The world can thus expect new temperature records for the oceans. – The temperatures are going off the charts and breaking previous records, says climate scientist at the University of New South Wales, Professor Matthew England, to The Guardian. Temperature in the world since 1880 compared to the average in the period 1991-2020 +0.5°C compared to normal? Click for explanation normal temperature18801900192019401960198020002020 Go to news’s Climate Status Why are most years blue and colder than normal? This is because all years are now compared to a new normal, that is, the average of weather in the 30-year period 1991-2020. These 30 years have been unusually warm. Most other years are therefore colder than normal. Until recently, researchers used a normal period that ran from 1961-1990. In these years it was relatively cold. It’s been quite a while since the 1960s and the new normal allows us to compare the weather with the climate (normal) that people actually experience today. The normal period is determined by the World Meteorological Organization (WMO), and is used in all countries . In this way, we can compare the weather in Norway with other countries and we can measure changes across the globe. How can you calculate one temperature for the whole world? This number is the result of a complicated calculation. Measurements are made with thermometers both on land and on the sea surface (at sea the thermometers are attached to buoys). In some places the thermometers are close together, in other places there is a long distance between them. Using a statistical method, the researchers are able to give the measurements different weights, so that all areas are equally important: The data used in this graph comes from the American NOAA. They have divided the globe into squares of 5° x 5° and calculate one temperature for each square. Then they can again work their way up to a global figure, for each month or for each year. They can also make figures for the temperature only over the ocean or only over land, or for the northern and southern hemispheres. The lines at the poles are smaller than along the equator due to the curvature of the globe. The researchers also take this into account in their calculations. Others, such as NASA or the Hadley Centre, calculate in slightly different ways than NOAA. Therefore, there are often small differences between the various data sets. In any case, the trend they show is the same: since 1880, the world has become warmer. Dampening climate change The record-high temperatures come at the same time as dramatic figures about the CO₂ level in the atmosphere become known. 2022 is the first year in which the level of CO₂ is more than 50 percent higher than it was in pre-industrial times. The ocean absorbs around 90 percent of the energy from global warming. The ocean is therefore important for keeping climate change in check. – Without the ocean, climate change would have been much, much stronger. The fact that it is so hot there now raises questions about how long the sea can continue to provide us with the services it does, says Bjørn Samset. Warmer seas cause the coral reefs to bleach, as here off the coast of Kenya last autumn. Photo: Brian Inganga / AP Could bring more or stronger hurricanes This year’s Atlantic hurricane season starts on June 1. – Warmer sea surfaces cause hurricanes, says Samset. A study last year shows that the heat penetrates faster and deeper into the sea than before. Warmer seas down in the depths cause heat waves that affect everything from coral reefs to fish stocks to everything else in the sea. – So the climate changes in the sea are at least as dramatic as those on land. It’s just that we know less about them, concludes Bjørn Samset.
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The world’s oceans have never been warmer than this Easter – news Urix – Foreign news and documentaries
