From a meteorological point of view, 2022 was one of the strangest and warmest years so far this century for Spain, and in the northern hemisphere. According to Spanish weather service AEMET, 2022 will be the warmest in the historical series.
In doing so, temperatures this year surpassed the averages of 2017 and 2020, which ranked second and third. Moreover, this was the fifth least rainy year since records have been kept in Spain. It is close to the driest years, which, in this order, were 1981, 2017, 2005 and 1995. This context is linked to AEMET‘s warning of a phenomenon that could occur for the first time this century.
As the weather service explained, “global temperature anomalies have been observed over the past 12 months. This makes it likely that the La Niña episode will last in the northern hemisphere until the end of winter. The episode is unusually persistent and prolonged,
Three consecutive years
It would thus be the “first “triple” La Niña episode of the 21st century, spanning three consecutive years,” according to AEMET, which in turn relies on predictions by the World Meteorological Organisation (WMO).
That organisation states in its latest report on the phenomenon that ‘the probability La Niña will persist in the period from December 2022 to February 2023 is about 75%. Furthermore, that percentage is 60% for the months January to March 2023,’ it said.
Consequences of large-scale cooling
As the WMO explains, La Niña is a cold sea current, a phenomenon that causes large-scale cooling of ocean surface waters in the central and eastern equatorial Pacific. In addition, the phenomenon leads to other changes in tropical atmospheric circulation, such as wind, pressure and precipitation. It generally has weather and climate effects opposite to those of El Niño, the warm phase.
Although La Niña is a natural phenomenon, WMO stresses that it occurs “in a context of climate change due to human activity, increasing global temperatures, increasing weather conditions to extreme levels and affecting the distribution of seasonal precipitation”.
Since 1950, there have only been three triple La Niña episodes, according to AEMET. In the case of the northern hemisphere, such a sustained episode ‘