Given the news of a meteorological record, such as the extremely high temperatures recorded this past week in western Canada (British Columbia) and the northwestern United States, the media temptation is to link its occurrence to climate change. The question is, however, complex and requires rigorous statistical analysis, which is not always conclusive. On the one hand, it must be borne in mind that a certain climatic state is not only represented by the values of the climatic variables close to the means, the most frequent; but also because of the values far from them, extreme, infrequent. There have always been years, months and days that are cold or very cold and others that are warm or very hot, which make up, along with the normal years, months and days, a certain climate.
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On the other hand, it is easy to show that the probability of breaking a meteorological record in a wide territory is high. Meteorological records are frequently broken without making it possible to affirm that there have been changes in the climate. This is so because there are several meteorological variables under study (temperature, precipitation, wind speed, etc.), different time intervals considered (hour, day, month, year), various periods observed (the last decade, in 30 years, a century, etc.) and many places with weather stations.
All-time records – the highest or lowest values ever recorded – require caution in attributing them to climate change. Even so, the absolute maximum temperature that has been beaten in western Canada, where it came close to 50 degrees Celsius, specifically 49.6 degrees, in Lytton, just over 150 kilometers northeast of Vancouver, constitutes a record hard to imagine so far for a place on the 50ºN parallel. Other weather stations in British Columbia also broke their records for as long as they have records, followed by devastating fires. Due to the exceptionality of these values and the unusualness of the atmospheric situation, it is possible to link this heat wave to global warming, in the absence of its confirmation through statistical analysis.
Global warming not only translates into the upward trend of average temperatures that is observed everywhere, but also in a greater frequency and intensity of heat waves. These and droughts constitute the two most serious risks of climate change in Spain, in addition to rising sea levels. The absolute maximum temperatures of our country have been registered in the Guadalquivir valley, touching 47 degrees, as the value of 46.9º that the State Meteorological Agency measured at the Córdoba airport, on July 13, 2017 (in the nearby town of Montoro the thermometer reached 47.3), lower, anyway, the Canadian record, in a place much more northern.
Excess heat increases morbidity and mortality, constituting a public health problem. Due to the latitudes that the Spanish territory occupies and the proximity of the Sahara desert, and in view of the temperature projections, we must be prepared for the possibility that in the next two decades somewhere in Spain the thermometers may line up close 50 degrees and exceeding 40 is often no longer news. Some cities, such as Barcelona, already prepare or have climate shelters, either in the open air (parks with lots of vegetation and fountains and sheets of water) or in covered spaces (schools and conditioned public buildings), to accommodate the people during the hottest hours of the day.
Although the temperature drops at night, if it does not drop enough, rest is difficult and the health of the elderly or those with chronic diseases suffers greatly. In the centers of our cities, where the general heat is added to the thermal plus of the so-called urban heat islands, the nights become unbearable, with the deterioration of the health of the aforementioned groups of people, especially if they are in conditions of energy poverty, without the possibility of using an air conditioner.
Expanding the perspective, a rapid energy transition is imposed to replace fossil fuels with renewable energies, free of greenhouse gas emissions. With a geographical, comprehensive approach to the problem, the energy transition should not be reduced to the aforementioned substitution, the required energy efficiency and the necessary technological improvements, but must guarantee the rebalancing of the territory and social equity. If the spaces of depopulated Spain (badly called emptied) host wind farms and solar plants, they should receive their fair compensation in resources, employment and new opportunities. Similarly, of what use would an energy transition be used that leaves the most disadvantaged sectors of the population abandoned, in a situation of energy poverty, even exposed to a fatal premature outcome?
Javier Martin-Vide He is a professor of Physical Geography at the University of Barcelona.
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