In 2023, Europe experienced its warmest year on record, ranking either first or second, depending on the inclusion of Greenland's data. The average temperature in the continent was 1°C higher than the 1991-2020 average, according to the report on Europe's climate status by the World Meteorological Organization (WMO) and the EU's Copernicus program. However, the most significant finding of the study is that while the global temperature increase compared to pre-industrial levels is 1.4°C, Europe has seen a rise of 2.6°C. What factors contribute to this difference?
Since the 1980s, Europe has been warming twice as fast as the global average. It is the continent experiencing this process the fastest. This is mainly due to the larger proportion of European lands in the Arctic, the region warming most rapidly on Earth (3°C since the 1970s).
Europe is generally located at rather high latitudes in the Northern Hemisphere, and moreover, a part of the continent includes territory within the Arctic Circle. "As the poles are the area that heats up the most on the planet, when averaging temperatures in Europe, which includes a part of the Arctic, the result is that temperatures rise more..." says Joaquín Muñoz, responsible for satellite climate monitoring at Copernicus.
Another factor that influences this is changes in atmospheric circulation, which favor more frequent heatwaves in the summer. This oceanic circulation brings warm waters to European coasts, making them relatively warmer than those of other oceans. "We have relatively mild winters when in equivalent latitudes in North America winters are much colder."
The Copernicus report for 2023 indicates that almost all regions of Europe experienced above-average temperatures for most of the year, except for Scandinavia, Iceland, and Greenland. It was the second warmest autumn, and in November temperatures were measured 6ºC above the average in Eastern Europe and the Arctic.
What explains the fact that 2023 has set new records? The main reason is the increase in concentrations of greenhouse gases, the warming caused by human activities such as the burning of fossil fuels, as explained by Joaquín Muñoz. Again in 2023, there were records in carbon dioxide and methane emissions.
Additionally, the high ocean temperatures have also contributed, as well as the natural variability associated with "El Niño", a cyclical warming phenomenon that begins in the equatorial Pacific with repercussions worldwide, although its influence is weaker in Europe.
Similarly, "a small contribution from the solar cycle, which is currently at a peak," has been detected.
And a fourth explanation is a reduction in aerosols in the atmosphere (which reflect solar radiation), due to a decrease in sulfur dioxide pollution in maritime transport.
The major breakthrough of 2023 has been the high ocean temperatures, "the highest on record," according to the report. In June, in the Atlantic (west of Ireland and around Great Britain), temperatures were measured 5ºC above average, and in June and August, that threshold was exceeded in Mediterranean areas. "El Niño" and increased radiation levels are believed to be the main causes.
One effect has been the proliferation of heatwaves. In Europe, 23 out of the last 30 most severe heatwaves have taken place since the year 2000. And in 2023, a record number of days with "extreme heat stress" was reached, which is equivalent to a temperature perceived as exceeding 46°C.
13% of the continent and 41% of Southern Europe experienced "strong," "very strong stress," or "extreme stress" due to heat on July 23.
In the last 20 years, heat-related mortality has increased by around 30%, and it is estimated that heat-related deaths have risen in 94% of the observed European regions.
The report notes that the "frequency and severity of extreme events are increasing" in Europe. Precipitation (7% above average) and floods (in Italy, Sweden, and Slovenia) were accompanied by drier-than-average conditions in countries located west of the Black Sea and in the southern Iberian Peninsula, where dry conditions prevailed from February to April.
Extreme weather events raised river flows exceptionally due to storms between October and December. According to preliminary estimates, in 2023, 63 lives were lost in Europe in events caused by storms, 44 due to floods, and another 44 from wildfires. It is estimated that floods affected 1.6 million people.
"The climate crisis is the great challenge of our generation. The cost of taking action may be high, but the cost of not acting is much higher," says Celeste Saulo, Director-General of the WMO. Economic losses related to meteorology and climate exceeded €13.4 billion, with 81% attributed to floods."
"In 2023, Europe witnessed the largest forest fire ever recorded and it was one of the wettest years, with severe marine heatwaves and widespread devastating floods," summarizes Carlo Buontempo, director of the EU's Copernicus Climate Service. "Temperatures continue to rise, making our data increasingly vital in preparing for the effects of climate change," he concludes.
And it was an exceptionally melting year in the glaciers of the European Alps. The number of snowy days in the Old Continent was below average, especially in central Europe and the Alps during the winter and spring. This, together with high temperatures in the summer, has contributed to causing a net loss of glacier ice throughout Europe. In the Alps, this loss was 10% of the volume they had left in 2022 and 2023.
Meanwhile, Copernicus' seasonal prediction indicates that there is a higher likelihood of having a summer with temperatures above normal for that time of year than not. "But this should not be something that surprises us, as the current scenario is dominated by a trend towards increasing temperatures," says the Copernicus expert.
"If we consider that the main factor causing temperatures to rise is the concentration of greenhouse gases, then we would have an even hotter summer in 2024; however, we must take into account that in 2023, El Niño and other factors have influenced the temperatures, so we cannot guarantee that it will be the case. A transition towards a neutral state or towards La Niña does not guarantee that temperatures will decrease."
