European State of the Climate 2023

“These extreme events have not only strained natural ecosystems, but they also pose severe challenges to agriculture, water resource management, and public health,” said Dr Carlo Buontempo, Director of Copernicus Climate Change Service at ECMWF. 

“Hundreds of thousands of people were affected by extreme climate events in 2023. Unfortunately these figures are unlikely to get smaller, at least in the near future. Both observational and model constraint facts point to an increase in the severity and frequency of climate drivers responsible for some of the impacts we have seen in the past few months.

“Despite our still imperfect knowledge, as a society we now have a set of useful tools which can guide our present reaction to emergencies, as well as inform our long-term strategy for climate. Climate data, information and insights have never been as important as they are now.” 

Some of the major climate events included in the report are outlined below. 

Heatwaves, wildfires, and droughts

2023 was the hottest year on record globally. In Europe, the average temperature last year was 2.5°C above pre-industrial levels, by some measures equalling the previous record set in 2020. The three warmest years on record for Europe have all occurred since 2020, and the ten warmest since 2007.

The ESOTC 2023 authors report that summer-like conditions started earlier and finished later than usual across much of Europe, with many regions hit by one or multiple heatwaves. Temperatures in Europe were above average for 11 months of the year, with September the warmest on record.

Particularly alarming were unprecedented periods of ‘extreme heat stress’ conditions across Southern Europe, where factors such as air temperature, humidity, windspeed, and thermal radiation combined to create a “feels like” temperature of 46°C or more. 

In July 2023, around 41% of the population of Southern Europe was exposed to ‘strong or extreme heat stress’ conditions, the largest area of Europe to be exposed at these levels on a single day since comprehensive records began. Specialists say that in such conditions it is imperative that people take immediate action to avoid health risks. 

Major droughts affected the Iberian peninsula in early summer and parts of Eastern Europe later in the year. The river Po, in Italy, was at record low levels for the time of year from February to April, with snowfall deficits in the Alps contributing to a continuation of a long-running drought from previous years. 

Hot conditions also helped fuel wildfires across Europe. In 2023, an area the combined size of London, Paris and Berlin burned over the course of the year. Large fires occurred in Portugal, Spain, Italy, and Greece, where an immense blaze has been confirmed as the European Union’s largest ever recorded wildfire. 

Storms, floods, and swollen rivers

The ESOTC 2023 authors describe last year as one of contrasts, with precipitation across Europe 7% higher than the long-term average for the year as a whole. This puts 2023 in the top four wettest years on record. 

While average river flows across much of the European river network were below average for much of the year, 2023 also saw several severe flood events, with a large number of rivers swelling to record or near-record levels late in the year. 

Following a series of major storms between October and December, exceptionally high river flows in river basins such as the Loire, the Rhine and the Danube, created emergency situations in several European countries. 

Major storms across the year also contributed to flood events that ranged from localised flash floods to flooding of major rivers. Severe flooding occurred in Italy, Slovenia, Norway, Sweden, Greece, Bulgaria, Turkey, Germany, the United Kingdom, and other European countries. 

Tens of thousands of people were temporarily displaced during these flood events and authorities reported dozens of fatalities. The most severe loss of life came in September when Storm Daniel crossed the Mediterranean Sea and struck Libya, where high rainfall and flash flooding burst dams and led to at least 4,700 deaths. 

Snow deficits, glacier loss, reduced sea ice cover 

Glaciers around the world saw a record breaking loss of ice at around 600 gigatons – 600 billion tonnes of water –, around 100 gigatons more than any other year on record. 

Europe was no exception, with hot temperatures and snowfall deficits exposing the continent’s glaciers to extensive melting in 2023. 

Every European region with glaciers saw substantial loss of ice. Glacial melt in the Alps was particularly severe, with abnormally hot temperatures and snowfall deficits contributing to “exceptional” ice loss, which came on top of record melting in 2022. 

The combined ice loss from Alpine glaciers in 2022 and 2023 amounted to around 10% of their volume. 

Melting was also profound in the Arctic, where average sea ice extents were well below average despite the late onset of seasonal melting around Greenland. 

Overall, temperatures in the Arctic are warming faster than almost anywhere else on Earth, and in 2023 were 3.3°C above pre-industrial levels. 

These warmer temperatures are also contributing to wildfires on land: emissions from wildfires within the Arctic circle were the second highest on record in 2023, continuing a trend of increasing wildfires in the world’s most northern latitudes. 

Sea ice extent in the Antarctic was the lowest on record. The decline of sea ice cover in the Antarctic since 2015 has surprised specialists, some of whom have raised concerns over the further environmental impacts this is likely to cause. 

Extreme marine heatwaves 

Another phenomenon that has taken specialists by surprise in 2023 was record-breaking average sea surface temperatures. 

Records were broken each month globally from April through to December. And in Europe, across 2023 as a whole, the average sea surface temperature of marine waters was the warmest on record. 

One striking example of these extremes was a marine heatwave in the north-eastern Atlantic that peaked on 21 June, with sea surface anomalies as much as 5°C above average, far higher anything seen in historical records. Ocean surface temperatures off the coast of the United Kingdom and Ireland were widely categorised as ‘extreme’ or ‘beyond extreme’. 

Another happened in the Mediterranean Sea, which experienced an extreme marine heatwave in July and August, with sea surface temperatures some 5.5°C above average in some areas.

While 2023 saw a transition from La Niña to El Niño conditions, where warmer conditions were expected in some parts of the global ocean, specialists report that high underlying temperatures in most ocean basins played a large role in the record-breaking sea surface temperatures. This means that El Niño was by no means the only contributing factor to the record sea surface temperatures seen in 2023.

Author:

Adam Gristwood