Climate warming: record temperatures in the Baltic Sea reveal the planet’s fever
It was a relief to dive into the Baltic Sea at the end of June and in the first half of July. Born along the northern sea coast, the locals do not remember that the water has ever been hot for so long, especially in early summer. Usually, it was possible to count on only a handful of days of warm water during the entire season. The wind rapidly dispersed the surface layers, and the water from the sea depth reached the shore. It was a very stark contrast: the beach was on fire, but the water seemed to come out of the refrigerator.
The observatories of the Institute of Meteorology and Water Management conduct daily water temperature measurements in the various scientific stations located at natural and artificial lakes and along the seashore. Let’s look at the data collected at 8.00 am on Wednesday 28 July. The highest water temperature along the Polish Baltic coast was detected in Kolobrzeg: the thermometer indicated 24.2 degrees. In Miedzyzdroje, the temperature was slightly lower, 23.6 degrees, while the meters of the other localities stated an average of over 22 degrees. In Ustka alone, the seawater temperature was 20.8 degrees. More than enough for swimming, at least in the Baltic.
Overall, the water in the Baltic Sea last Wednesday morning was almost as warm as in the Polish lakes, where the thermometers of the Institute of Meteorology and Water Management indicated an average of about 24 degrees. The website of the Danish Meteorological Institute for viewing satellite measurements of the surface temperature of the Baltic Sea has a larger scale: up to 34 degrees.
The question arises: does not such a high temperature of the Baltic water constitute a threat to us and the environment? “The surface water temperature of a sea as shallow as the Baltic reflects the temperature of the atmosphere which, as is well known, is strongly influenced by the ongoing climate changes,” explains Professor Piskozub. According to calculations by climatologists from the Institute of Meteorology and Water Management, June this year in Poland was a scorching month (this is an official category of the Institute: seasons or months can be strange or thermally normal, hot/cold or extremely hot or cold). The air temperature in the southern and eastern Baltic coastal area reached 18.7 degrees in June, three more than the monthly average recorded over the years.
This average results from the 1991-2020 measurements, thirty years strongly characterized by global warming.For the analysis of the temperatures in July, it will be necessary to wait a little longer. Still, they were clearly above the long-term seasonal average. Precise data on the water temperature in the southern Baltic are collected by the Institute of Meteorology and Water Management as part of national environmental monitoring. They come from coastal stations, where the water is usually warmer, and from surveys conducted in the open sea throughout the year. During these scientific missions, the surface water temperature is measured and at different depths.
“Our surveys in the southern Baltic Sea over the past sixty years show an increase in the average annual surface water temperature,” Professor Tamara Zalewska from the Institute above told the local Gazeta Wyborcza. “In the period from 1959 to 1999, it was usually below 10 degrees. Since 2000, however, this limit has always been exceeded. 2018 was the hottest year for the southern Baltic. The average temperature of its surface waters that year was 14.2 degrees “, emphasizes the researcher.
This trend of rising temperatures is so clear that it is “statistically significant.” In other words, it is not the accidental result of the weather capric (the warming or cooling of the water of the Baltic Sea) but indicates a significant change that cannot be dissociated from the ongoing climate changes. In any case, it is a phenomenon on a global level. Almost all of the hottest years in the history of Earth have been recorded in the 21st century. Europe is warming up twice the average of other continents.