For more than 40 years, since official records began to be kept, the average temperature of the seas and oceans had never before reached 21.1° Celsius, a figure it finally reached on April 5, reports the U.S. National Oceanic and Atmospheric Administration (NOAA).
The highest average sea and ocean temperature NOAA had on record was 21.0° Celsius dated 2016, which coincided with. El NiñoThe climate is a natural cyclical climatic phenomenon that warms the waters of the tropical Pacific.
Francisco Martín Leónmeteorologist and coordinator of the Revista del Aficionado a la Meteorología, states that this increase in the average temperature of the seas and oceans is a consequence of the global warming caused by emissions of greenhouse gasesThe climate was neutral during this period.
"We are entering uncharted weather and climate territory and pushing boundaries that have never been crossed before," he says.
The oceans are subject to two natural cyclical climatic phenomena, changing and opposing: El Niño, which warms the waters of the tropical Pacific, and La Niñawhich cools them, he explains. Three years of La Niña in that ocean have helped reduce temperatures and cushion the effect of increased greenhouse gas emissions.
"In 2016 there was a warm phase with positive anomalies, which was called the Super Niño, which contributed so much to the rise in temperatures that the last record was reached. However, right now La Niña has just ended, which means that even being in a neutral phase in the tropical Pacific all modern records are being exceeded," he says.
Since 1981, NOAA has been observing the behavior of the Earth's open waters via satellites, buoys and ships and estimating sea and ocean surface temperature (SST). Although this is a relatively short period in terms of climate, it is the most reliable data on the subject.
The agency's preliminary measurements show that last April 5, seas between 60 degrees north and 60 degrees south, i.e., all but the poles, exceeded 21°C.
What are the consequences?
Martín León points out that global warming of anthropogenic origin (caused by humans) is being stored in marine waters and as a consequence between 80% and 90% of the excess energy ends up in the oceans.
"Because of this, the seas are also suffering from heat waves, and as a result we are having abnormally high temperatures at this time of year in the North Atlantic and Mediterranean as well," he says.
In fact, the north Atlantic has exceeded 22°C, which is unusual for the middle of spring, while the Center for Mediterranean Environmental Studies (CEAM) has also warned of exceptionally warm measurements in the sea around the Iberian Peninsula.
On his Twitter account, Juan Jesús González AlemánSenior State Meteorologist at Spain's State Meteorological Agency, warns that the oceans are entering uncharted territory.
"In their upward warming trend of the last tens of years, in the last week they have surpassed the 21°C surface temperature barrier at the global level. Something never seen since records have been kept [...] Something very striking is what is happening in the North Atlantic, where we have already had a month of record warming," he writes.
Oceans enter uncharted territory👇:
In its upward warming trend of the last tens of years, in this last week have exceeded the barrier of 21ºC of global surface temperature.
Something never seen since records have been kept. pic.twitter.com/ozjsxy1mle- J. J. González Alemán (@glezjuanje) April 10, 2023
Francisco Martín León emphasizes that with the emission of greenhouse gases, human beings are doping the atmosphere and the oceans and this has consequences on the meteorological system.
He warned that when the next El Niño arrives, predictably during next summer, even higher sea temperatures are expected.
"The problem is that greenhouse gases already have more intense effects than El Niño or La Niña. In the past, when there was a La Niña phase, there was some cooling of the earth's temperature, but it is becoming less noticeable."
The warming of the seas causes them to generate more water vapor and this has effects on meteorology: in these conditions, if a front, a squall, enters, it is very likely to produce very intense precipitation. The warmer the waters, the greater the probability of extreme weather phenomena.
In addition, he notes, these conditions increase heat stress in marine animals, which can affect the food chain and, ultimately, human food.
Source: La Nación
