The year 2023 has been the warmest recorded so far on the planet based on global temperature data dating back to 1850. The average global temperature in 2023 was 14.98°C, which is 0.17° C above the previous record, which dates back to 2016. The result is that in this way the planet’s climate is already 1.48ºC above the pre-industrial level, very close to what was established in the Paris Agreement.
As predicted, 2023 has become the hottest year. This was predicted by the EU’s Copernicus Climate Change Service. And so it has been confirmed. It was also the first year in which every day was more than 1°C warmer than the pre-industrial period.
The Copernicus service’s own data dates back to the 40s of the last century; but it also handles reliable series of global temperatures from pre-industrial times to now. “2023 has been the hottest period since pre-industrial times. But if we look back and use scientific knowledge about paleoclimatology, we can conclude that it is extremely likely, almost certainly, that it has been the year with the highest temperatures in the last 100,000 years,” says Carlo Buontempo, head of the EU Copernicus Climate Service.
In fact, the first signs of how unusual the year 2023 was going to be began to emerge in early June, when temperature differences with respect to the average of the pre-industrial era (1850-1900) reached 1.5°C for several consecutive days.
Although it was not the first time that daily anomalies reached record levels, this circumstance had never before occurred at this time of year (in June). It was the hottest summer in history, and during the second half of the year anomalous daily global temperatures above 1.5°C became commonplace. The consequence is that about 50% of the days in 2023 exceeded the 1850-1900 level by 1.5°C; and two days in November were, for the first time, more than 2°C warmer.
The Copernicus service also considers that “it is likely” that in a 12-month period ending in January or February 2024, 1.5°C above the pre-industrial level will be exceeded.
During the past year, every month between June and December has been warmer than the corresponding month in any previous year. And July and August 2023 were the two warmest months on record, while the northern summer (June to August) was also the warmest season on record. September 2023 was the month with a greater temperature deviation compared to the 1991-2020 average in the analyzed data set.
The sum of generalized global warming, detected in all continents and in all oceans, together with the El Niño Southern Oscillation (ENSO) explains the unusual records of 2023, according to the director of the Copernicus Climate Service, “They are factors that add up to each other,” the Italian physicist tells this newspaper.
This year has been marked by the influence of El Niño (a warming originating in the equatorial Pacific that occurs in cycles of between 3 and 7 years, with impacts on a large part of the planet) and which has constituted a particularly intense episode in the second semester of the year.
Conducive conditions began to develop at the beginning of 2023; The World Meteorological Organization declared the beginning of this episode in July, and the phenomenon continued to strengthen during the rest of the year.
However, El Niño alone does not explain the fact that temperatures have approached the 1.5º limit. as high temperatures outside the equatorial Pacific contributed significantly to these unprecedented rise levels.
Warming is largely a consequence of greenhouse gas emissions, and this year there has been an increase in these concentrations in the atmosphere again, recalls Buontempo. “For all this, we could not expect anything different from the warming that has occurred to occur. “El Niño adds more heat to what occurs due to warming,” he says.
“The climate depends on many factors and therefore it cannot be ruled out that these other factors may have intervened, such as the planet’s orbital parameters, variations in solar energy or volcanoes. But these contributions have not been particularly important this past year. What we see in 2023 is basically explained by greenhouse gas emissions and the El Niño phenomenon,” he adds.
Buontempo also recalls that the polar ice in Antarctica has registered very significant decreases throughout the year and has clearly contributed to this entire situation, “the same as the North Atlantic, which has registered marine heat waves.”
Global average sea surface temperatures remained persistently and unusually high, reaching record levels for the April to December time of year.
In fact, high sea surface temperatures in most ocean basins, and particularly in the North Atlantic, played an important role in these unprecedented records, the report says.
All of this led to marine heat waves around the world, including in parts of the Mediterranean, the Gulf of Mexico and the Caribbean, the Indian Ocean and the North Pacific, and much of the North Atlantic.
Mean annual air temperatures were the warmest on record (or very close to them) on all continents except Australia, as well as in considerable parts of all ocean basins.
In this sense, in 2023, there has been “a very important contribution from the continents of the Northern Hemisphere”, that is, Eurasia, Europe, Russia and Siberia, as well as North America, without the latter being common. In recent decades, the Arctic has been the area of ??the planet “where the increase in temperature has been most important,” according to Carlos Buontempo. And, in the same way, “Europe, in general, has also been warming more quickly than promised, although the last year has not been as extreme.”
The most worrying element has been observing how warming approached the limit of 1.5 ºC.
It must be taken into account that stopping the temperature increase by 1.5ºC is the first objective set in the Paris Agreement against warming signed by 196 countries.
“We have been slow in releasing the report because we were evaluating whether the limit of 1.5ºC is reached; and, in the end, we stayed just a little below (1.48ºC)”, says Buentempo.
The Italian physicist and climatologist points out that the limit set in the Paris Agreement will be exceeded. However, he specifies that this established 1.5ºC limit refers to a sustained exceedance over a period of 20 years. And, from this point of view, the forecast is that it will be exceeded “around the year 2034, in the mid-1930s of this century.”
“What we do see is that as we get closer to that date, we see days, weeks and months in which that threshold is crossed more frequently, and there will be a time when every year we will be above that goal,” he highlights. .
And how will El Niño affect the year 2024? Buontempo highlights that “normally, if we look back, the year in which the peak temperatures are reached is usually the year that follows the El Niño episode”, which means that “2024 begins with all the numbers to be another year of heat.” and it could be a year of records.”
However, all of this remains to be seen, since it will depend on the oscillation of El Niño and what time of year it can evolve into a warm episode.
“The peak of El Niño is expected for immediate current dates; and the forecast is that the warming in the Pacific Ocean will decrease, so that it will reach almost zero in June,” says Buotempo. Therefore, if it evolves sharply towards a cold episode (La Niña) “the temperature record could be mitigated a little”; “But if the evolution remains neutral and El Niño does not drop to zero quickly, as the predictions say, the year 2024 could break a new record.”
What is clear is that “if we look further, what is true is that, on average, the temperatures of the next five or six years will be higher than the last five years; That’s very likely.”
