Climate change doesn't just mean getting hotter in the summer. Among the countless consequences, there are also those that affect our health in very diverse ways. Stopping the escalation of temperatures is a matter of public health, as Rachel Lowe, research professor at ICREA (Institució Catalana de Recerca i Estudis Avançats), head of the global health resilience team at the Barcelona Supercomputing Center ( BSC) and director of Lancet Countdown in Europe, an organization that in the 2022 report explained how global warming is causing loss of life, money, and threatens the health of billions of people.
How does the supercomputer MareNostrum help to know the effect of climate change on our health?
The supercomputer allows us to analyze a whole series of data sets, especially climate data, and make very precise observations, predictions and projections about how the climate has changed in recent years and how we expect it to change in the short term, from months to years, and also until the end of the century. And that can help us create different scenarios for how health will be affected by climate, depending on what kind of decisions governments make about adaptation and mitigation strategies.
What can be seen now?
Right now, for example, you can see that people in one part of Barcelona are probably more likely to contract some diseases caused by the climate. Climate impacts are uneven, and certain people in society more vulnerable to the impacts of climate change. And also, we see this kind of variation all over the planet.
Who is more vulnerable?
The inhabitants of the South suffer the worst consequences of climate change, despite the fact that they are the least responsible for contributing to anthropogenic climate change. In Europe we can see that the south is more vulnerable to increased climatic suitability for infectious diseases, reduced labor productivity due to extreme heat and unsafe hours for outdoor exercise. Within cities, it depends on socio-economic conditions. Regarding infectious diseases, proximity to mosquito breeding sites and the ability to protect yourself.
You have data to teach those who make political decisions.
We can use climate information generated by supercomputers and then translate that information into meaningful health indicators that can really show how much climate change is affecting our health. For example, we can track changes in temperature-related mortality, by sex and age, and see which groups are particularly vulnerable and where they are most affected. We can also see how the length of the transmission season for diseases such as dengue and malaria increases.
These diseases were not in Europe until recently.
This has a huge risk in Europe, especially because there are parts that are very well connected to other parts of the world that experience endemic transmission of these diseases. So through travel and trade, combined with climate change, there is a real risk that these diseases will become established in Europe.
What are the current conditions in Spain?
In the latest Lancet Countdown report of 2022 we have shown that Spain is at a much greater risk related to temperature than the European average. In fact, there is also a greater tendency for the mosquito transmission season to be extended. And it also shows less labor productivity due to the heat. So Spain is definitely a hot spot, the Mediterranean region is warming much faster than the global average. It is definitely a place where you need to act immediately.
Is there any area free of these risks?
It's definitely a global problem. It affects the health of everyone everywhere. There are certain areas that are more vulnerable, for example cities, coastal areas, mountainous areas, areas that are more exposed to sea level rise or melting glaciers, which are exposed to flooding. And then certain groups in society that are more vulnerable, such as children, women, the elderly, people with socio-economic difficulties, people with disabilities. Despite the fact that everyone's health has been threatened, we must act collectively to really make sure that we are protecting the most vulnerable sectors of society.
How do you work with a supercomputer to get all this evidence?
To input information into our health impact models, we use a range of different climate and Earth observation data. These can be grid products, which represent the climatic conditions of the entire planet, at a spatial scale of about nine kilometers. It is a kind of maps that represent the conditions throughout the planet, over many decades, with an hourly temporal resolution. We also use weather station data from drone imagery. And we can use this kind of images to correct satellite images on a larger scale. We combine all the information to try to make the best possible representation of what is happening on the ground. We can then integrate the data into our health impact models to help us predict how likely it is that a dengue outbreak will occur in that particular area. Or where malaria is most likely to re-emerge, for example.
Can you predict which people are already threatened?
We published a projection in which we estimated that we were seeing the change in the length of the transmission season and the population at risk for both dengue and malaria worldwide. We calculated that if warming continues as it has been, we could see 4.7 billion more people at risk of these diseases by the end of the century, while if we made a concerted effort to keep global temperatures below one degree centigrade, the figure would be halved.
How can it be avoided?
This shows the importance of ensuring that we do not exceed dangerous limits for human survival and that we keep the global temperature below 1.5 degrees, because this will have a huge impact on the population at risk of contracting diseases such as now dengue and malaria. This was the study we did. But these dangerous temperatures are also going to have many impacts, as we can see happening now with temperature-related mortality, wildfires, these are just huge impacts of these extreme temperatures.
What would be your message to decision makers?
I think I would tell them that climate action is not only good for the climate, but also for our health. Taking steps to reduce emissions has enormous health benefits. For example, changing the way we travel. Increasing active transport not only leads to cleaner air, but also improves people's physical activity; changing diets to stop eating meat, which causes a huge amount of emissions that can also help and also make people live longer, healthier lifestyles. Everything we can do to improve access to energy in the city and the way we move around is good for the planet and good for our health.
What is the situation in Barcelona regarding climate and health?
In Barcelona and the surrounding regions, we have the tiger mosquito, capable of transmitting diseases such as dengue, chikungunya and Zika fever. There is a surveillance program to be aware of imported cases and to control mosquitoes around these cases to try to stop transmission. But this kind of system can only work for a while. So we need to make sure that all the surveillance systems are very integrated, that we understand exactly what kind of major diseases are coming in, what the distribution of mosquitoes is, who is most at risk and make sure that we can break any cycle transmission
Something else?
We need to reduce traffic and pollution in the city. Barcelona has one of the worst air pollution rates in Europe. Drastic measures need to be taken to mitigate the air pollution situation here.
