Climate (set of atmospheric conditions that characterize a region), meteorology (the science that studies atmospheric phenomena) and weather (if it rains, is hot or cold at a certain time) are not the same.
Hicham Achebak, a researcher at ISGlobal, a center promoted by the La Caixa Foundation, studies how climate change influences human health.
But in order not to confuse his speech, he warns that he will use the three words as synonyms.
This Spanish scientist born in Larache (Morocco) warns of the health problem that the rise in energy prices can bring.
Because access to it and the possibility of making homes increasingly comfortable with heating and air conditioning is the key, he says, to reducing deaths from heat and cold.
Ask.
How does weather affect health?
Response.
Climate, or meteorology, is the environmental factor that most determines human health.
And the most important variable is temperature, which affects people due to thermal stress, which occurs as you move away from comfortable temperatures: with the heat of summer and the cold of winter.
But there is no definition of hot or cold from a health point of view.
Maybe for me in Spain a temperature of 10 degrees on average is cold, but for Norway it is a warm day.
P.
Aren't there some parameters from which health begins to suffer?
R.
Humans have an enormous capacity for adaptation, and we are adapted to the local climate.
An average temperature, for example, of 25 degrees would have more impact in Denmark than in Spain.
That's why in Barcelona in winter I go very cold and I see Nordics in short sleeves.
Q.
How does that thermal stress work?
A.
It can be caused by heat or cold.
The direct consequences are heat stroke or hypothermia: like the poor cleaning employee who dies from working in the sun with inadequate clothing, or the one who sleeps on the street in winter and dies from the cold.
But most of the people who die due to the effect of temperatures do not do so for these causes, but for an aggravation of some basic pathologies, which can be of the circulatory, respiratory system, people who have diabetes, who suffer from some kidney diseases, for instance.
And most people who suffer from this aggravation are older, because they have less ability to regulate body temperature.
The temperature, in addition, not only produces deaths, but also an increase in hospital admissions.
Q.
Does cold or heat kill more?
R.
In Spain, more than 80% of all mortality associated with temperatures is attributable to cold.
But it is a matter of frequency: there are many more cold days per year than hot days, if we compare it with the average comfort temperatures.
But with climate change, the temperature is increasing, the summer will be longer and the winters will be warmer.
So over time we are likely to have more hot days than cold days, and if vulnerability stays the same, the weather will cause more heat deaths.
Q.
What is vulnerability?
R.
We could say that it is the risk of dying due to the weather;
it is a dynamic factor.
The better adaptation to climate, the less vulnerability.
For example, if in Spain the risk of dying with an average temperature of 28 degrees decreases, it means that vulnerability is decreasing.
And it is something that has happened in recent decades in Spain.
Despite the fact that it is getting hotter in summer, the risk of dying has been decreasing.
Q.
Why?
R.
In Spain it has been produced above all by socioeconomic development, which has been spectacular since the Transition.
There are improvements in the health system, the income level increases, people have more access to heating, air conditioning.
This means that the population has more tools to alleviate the effects of both heat and cold.
In 1991, about 5% of homes in Spain had air conditioning.
Now we are around 35%, although with the price of electricity it does not mean that it is always used.
But it is a figure that I see low, for the temperatures in Spain, which will continue to rise.
It will have to increase a lot in the coming years because it is one of the most effective adaptation measures.
Air conditioning is going to become a basic necessity with rising temperatures.
P.
We have the problem of the price of energy.
Not everyone can afford to turn it on, even if they have it.
R.
Yes, we see that excess mortality due to temperatures occurs in older people and by social strata: it affects the most disadvantaged more.
Q.
Will the possible energy problems that we will have this winter influence the health of the population?
R.
It is one of the things that I am investigating.
We'll have to analyze the data, but if people don't put on the air conditioning or heating because they can't afford it, it's more likely that there will be more deaths from heat and cold.
P.
This summer we are having a huge excess mortality: many more people are dying than expected for this time of year.
What do you think is happening?
A.
This summer we are seeing very high temperatures and very persistently.
They haven't given us a break.
Other summers, between heat waves there were days of descent, but this has been practically continuous since June.
It is even hotter than 2015. What has changed since then?
On the one hand, the covid continues to kill and that must be added.
The price of energy has also risen, and it is possible that this is already being felt in less use of air conditioning.
Q.
If you subtract the estimated deaths from covid in July, the excess mortality is quite similar to that of 2015, the previous year with such a hot July.
But the MoMo (the daily all-cause mortality monitoring system) attributes only a small part of excess mortality to heat, both then and now.
Thousands of deaths remain without a clear explanation.
The model is nothing more than a statistical estimate, not a count, can it be wrong?
R.
I believe that this excess mortality is basically due to this persistence of these high temperatures.
The model may not be able to predict the cumulative effects of so many hot days in a row.
Who knows if this same heat would have produced the same deaths in 2019, when the price of energy was lower and perhaps more people turned on the air conditioning.
There is also talk of a general worsening of the population's health [as a consequence of covid and hospital saturation derived from the pandemic].
If this has happened, people will also be more vulnerable to heat, so I think it's because of this.
I see no other cause that could explain such a sudden rise in mortality.
P.
Do you think that the energy saving measures that the Government has approved can have some impact on health, for better or for worse?
R.
In principle they should not have a significant impact.
In any case, it can still be beneficial by greatly reducing thermal contrasts.
Maybe it can prevent some colds, but beyond that it won't do anything.