Opinion – Esper Kallás: Global warming could open the door to new pandemics

The consequences of the increase in the planet’s temperature are commonly exemplified with images of fires, melting of immense polar plates and gigantic waves engulfing coastal regions and beaches.

There are, however, other threats contained in this phenomenon. Temperature changes lead to profound destabilization of ecosystems. Changes in the behavior of animals and germs can increase the risk of new “leaps” from one species to another. Although these are recurring events, sometimes a germ can find ideal conditions for its spread leading to an epidemic or pandemic.

An example of this occurrence dates back to the year 536 AD, after the eruption of the Krakatoa volcano. The Earth’s temperature dropped abruptly due to the presence of dense smoke that spread through the atmosphere, decreasing the penetration of sunlight.

This caused a change in the behavior of rodents that, looking for food, expanded their range of travel, coming into close contact with the human population. Along with the rodents came ticks contaminated by the Yersinia pestis, the causative agent of the Black Death. By 541 AD, the disease had killed at least a quarter of the population of the Byzantine Empire.

Although what happened in the 6th century was a radical event, with the Earth cooling by blocking sunlight for 18 months, the changes resulting from the current global warming impose a serious reflection on the subject.

Analysis carried out by scientists from several countries, published in recent days, helps to understand the problem. Although it is already known that there are thousands of germs capable of infecting humans, the vast majority silently inhabit wild animals, which have little current contact with people.

Carlson and his colleagues, in an article published in the scientific journal Nature Climate Change, build a map that takes into account the network of interaction between mammals and viruses in different regions of the planet. The analyzes project that the places most likely for these jumps of viruses between different species to occur are concentrated in regions with a tropical climate, where there is greater species diversity and close proximity to dense populations.

Brazil, particularly because of its extensive areas of hot climate and great biodiversity, is an integral part of what many researchers have called hot spots, that is, places that present more favorable conditions for jumps to take place.

These observations reaffirm how fundamental it is for the country to devote priority attention to the issue. Especially because of the huge number of changes that have been taking place in the Brazilian forest regions in recent years, as well as in the Pantanal, the cerrado and the caatinga.

Recent Brazilian data, which record the loss of forest area equivalent to the extension of the state of Rio de Janeiro, point to an increase in the probability of encounters between viruses that walk silently in wild species with humans.

It is possible that humanity has already entered the era of pandemics. New diseases are becoming more common and will test our ability to prepare and react.

The yellow light was lit two decades ago. Humanity is increasingly vulnerable. It is essential to discuss the emission of greenhouse gases, temperature increase and other radical changes that we have caused to the planet, with the effect it can have on infectious diseases. It’s time to deal with the red light.