2023 has been the warmest on record on the planet so far using global temperature data dating back to 1850. The global average temperature was 14.98°C, which is 0.17°C above of the previous record, which dates back to 2016. The result is that, in this way, the planet 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 it has also been the first year in which every day has been more than 1 °C warmer than those of the pre-industrial period.
To prepare this data, the Copernicus service has records that go back to the 1940s; but it also has reliable series of global temperatures from pre-industrial times to the present. "2023 has been the hottest period since the pre-industrial era. But if we look back and use scientific knowledge about paleoclimatology, we can conclude that it is extremely likely, almost certain, that this was the year with the highest temperatures in the last 100,000 years", says Carlo Buontempo, director of the Copernicus Climate Service of the EU.
The first signs of how unusual it would be in 2023 began to be detected at the beginning of June, when the temperature differences with respect to the average of the pre-industrial era (1850-1900) reached 1, 5°C in a streak of several days in a row. Although it wasn't the first time it had happened, it had never happened before at this time of year (in June). Then came the hottest summer and during the second half of the year the anomalous daily global temperatures above 1.5°C became a regular occurrence. The Copernicus service also considers that "it is likely" that in a period of 12 months ending in January or February 2024, 1.5°C will be exceeded above the pre-industrial level.
In the past year, every month between June and December has been warmer than the corresponding month in any previous year.
And what are the causes of this situation? The sum of generalized global warming, detected on all continents and in all oceans, together with the Southern Oscillation of l explain the unusual records of 2023, according to the director of the Copernicus Climate Service. "They are factors that are added on top of each other," the Italian physicist told this newspaper.
The year was marked by the influence of l , a warming originating in the equatorial Pacific that takes place in cycles of between 3 and 7 years, with impacts on a large part of the planet. Favorable conditions began to develop in early 2023, and continued to strengthen throughout the rest of the year. However, El Niño alone does not explain the fact that temperatures have approached the 1.5°C limit, as high temperatures outside the equatorial Pacific contributed significantly to these unprecedented increases.
The warming is largely due to greenhouse gas emissions, and this year there has been an increase in these concentrations in the atmosphere again, recalls Buontempo. "adds more heat to what takes place due to warming", he says. Other factors (orbital parameters of the planet, variations in solar energy or volcanoes) have not made particularly important contributions. "What we see in 2023 is basically explained by greenhouse gas emissions and the phenomenon of l", he adds.
Buontempo also recalls that the polar sea ice in Antarctica has recorded very significant declines throughout the year and has helped shape this panorama. 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.
In any case, the most worrying element has been observing how the warming approached the limit of 1.5ºC, the goal that marks the first objective of the signed Paris Agreement against warming. The limit set in the Paris Agreement will be exceeded. However, Buontempo clarifies that this limit refers to a sustained exceedance over a period of 20 years. From this point of view, the forecast is that it will be exceeded "around 2034, in the middle of this decade". "What we do see is that, as we get closer to the date, we see days, weeks and months that the threshold is crossed more often, and there will be a time when every year we will be above this goal", remark
And how will El Niño affect 2024? Buontempo emphasizes that, "normally, the year in which peak temperatures are reached is usually the year that follows the episode of ", so that "2024 starts with all the numbers to be another year of heat and it can be a year of records".
Even so, it will have to be seen, as it will depend on the oscillation of l and the time of year when it may evolve into a warm episode.
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; this is very likely."
Warming has been particularly intense in the continents of the northern hemisphere (Eurasia, Europe, Russia and Siberia, as well as North America). In recent decades, the Arctic has been the area of the planet "where the increase in temperature has been most important".
