More than a feeling: summers in Spain really are getting longer and hotter

It¡¯s more than a feeling: there are figures to back it up. Climate change has come to Spain, and its effects are mainly noticeable in the higher temperatures. The summer season now lasts almost five weeks longer on average than it used to in the early 1980s. And it is also hotter.

These are some of the conclusions of a new joint report from the national weather agency AEMET and the Ministry for Ecological Transition. Both institutions have offered data from the Open Data Clim¨¢tico project, which collects evidence of the impact of global warming on Spain in the last 40 years.

An increasingly warm Mediterranean has an impact on coastal regions, with a rise in tropical nights

Beatriz Hervella, AEMET

According to the ministry, more than 32 million Spanish people are affected by global warming. Beatriz Hervella, an AEMET spokesperson, said that these people live in parts of Spain where the summers are now longer and hotter.

There has been an accumulation of very warm years in the last decade, and an increase in so-called ¡°tropical nights,¡± or nights with a minimum temperature of 20?C.

Minister Teresa Ribera underscored the cause of climate change: the greenhouse gas emissions cause by human activity. She also noted that the International Energy Agency has warned that emissions of CO₂ ¨C the main greenhouse gas ¨C by the energy and industrial sectors reached a new record in 2018.

The AEMET report also highlights that in Spain, the surface area with a semi-arid climate has increased in the last 50 years by 30,000 km² ¨C similar in size to the entire region of Galicia. The most affected areas are the region of Castilla-La Mancha, the Ebro valley and southeastern Spain. These are areas with classic or continental Mediterranean climates that have turned into semi-arid places with less rainfall, according to Rub¨¦n del Campo, another AEMET spokesperson.

The analysis is based on data collected by 58 observatories, 52 of which are located in or near provincial capitals and in the exclave cities of Ceuta and Melilla in North Africa. Six more were added because of the particular historical relevance of their data sets.

The analysis found that for at least five years since 2011, 37 observatories registered ¡°average annual temperatures within the hottest 20% in the reference period.¡± The most extreme example was the Barcelona-Airport observatory, where every year since 2011 has been very hot.

As for the four seasons, their average temperatures are higher, although ¡°the rise is more noticeable in the spring, and especially in the summer.¡± Summers in Spain are also getting longer and hotter, says the report. The study found that ¡°the summer season now lasts five weeks more than it did in the early 1980s.¡±

The summer season, which AEMET defines solely by the temperatures, now starts earlier. According to the Madrid-Retiro weather station, in the 1970s the summer used to begin on July 15 and end on September 16. These days, it starts on June 11 and ends on September 22.

Mediterranean Sea

The report also analyzed the temperature of surface water in the Mediterranean, and concluded that it has been rising by 0.34?C every decade since the early 1980s. This in turn is causing the sea level to rise. Since 1993, the global sea level has been rising 3.4mm a year.

¡°An increasingly warm Mediterranean has an impact on coastal regions, with a rise in tropical nights,¡± said Hervella. These hotter nights make it difficult to sleep, which in turn ¡°has an impact on health.¡± A clear example of this is Alicante, she said, although inland cities such as Madrid can also experience tropical nights because of the ¡°heat island effect¡± created by buildings that trap warmth.

English version by Susana Urra.