High temperatures recorded in the past do not rule out climate change

Amid the heat wave in Europe, posts remembering former extreme temperatures have gone viral on social media in an attempt to deny climate change.

The publications presented calendars, reference tables and news from previous decades to show, for example, that thermometers in Spain have already reached 50°C.

Experts caution, however, that these heat spikes do not contradict global warming and that these publications are misleading, as they present isolated data not compiled correctly.

52°C in Zaragoza?

One of the posts features an article published in The New York Times on June 23, 1935 which states that the day before the thermometers in Zaragoza reached “127 degrees Fahrenheit”, equivalent to 52.7°C.

The number is much higher than the national record set by the State Meteorological Agency (Aemet), of 47.6°C on La Rambla (Córdoba) on August 14, 2021.

Contacted by AFP Fact-Check, Aemet spokesman Rubén del Campo said the maximum reached that day in Zaragoza was 39°C. “The temperature of 52 degrees is incorrect. It is not in our database and, in fact, there is no record that exceeds 50 degrees”, he argued.

In any case, “even if it were correct, I insist, it would not be proof that climate change does not exist,” he said.

The newspaper La Vanguardia also in 1935 echoed this news, adding that 51 and 52 degrees were recorded “under the sun”.

Experts warn that the criteria to ensure a correct measurement must meet parameters.
“The sensors must be protected from the sun and rain, and the temperature inside the station must be the same as outside,” said Ricardo Torrijo, meteorology technician at Aemet. Therefore, if 50 degrees were recorded under the sun, as La Vanguardia recognizes, it would not be a valid record.

A similar case cited the August 1957 weekly El Español and its headline “Hottest summer of the century”, which warned of temperatures around 50 degrees. This number had also been measured under the sun.

An abnormality does not change the trend

Isabel Cacho, from the University of Barcelona (UB) and a specialist in the planet’s natural climate variation, told AFP that, “in the hypothetical case that” these 50 degrees have been reached, “it would not be an argument to question that the current situation is hotter”.

“The abnormality of this particular day has a very small effect on the average (of temperatures) and the trend does not change,” added Pedro Zorrilla, a Spanish expert on climate change and fossil fuels at Greenpeace Spain.

José Luis García, another climate change expert and spokesperson for Greenpeace Spain, added: “These high temperature data do not serve to discredit the existence of climate change (…) One thing is temperature spikes and another, very different, is the trend increase and the average temperature”.

Experts also agreed that in the last decade extreme weather phenomena have increased as a result of climate change.

Events such as heat waves occur more and more frequently, said in June the doctor in geography and history Mariano Barriendos, from the University of Barcelona.