According to IPBES, an international group of experts on biodiversity: “future pandemics will appear more often, spread more quickly, cause more damage to the global economy and kill more people than Covid-19 unless the global approach to fighting infectious diseases is changed.” The threat of new epidemics hanging over our heads comes largely from what we call zoonoses: diseases that are transmitted between animals and humans. According to the WHO, 60% of human infectious diseases have an animal origin and this percentage even rises to 75% if we focus on the last 30 years. Among these zoonoses, we can cite the famous Ebola, Mpox or even mad cow disease, without forgetting Covid-19, which has caused millions of deaths across the globe. We know that humans are taking up more and more space and encroaching on that of animals. It is estimated that approximately 75% of the Earth's surface has been significantly degraded by humanity. Figure which includes deforestation, urbanization or even these ecosystems converted into cultivated land. And all of this, coupled with intensive breeding or even international trade, facilitates the circulation of pathogens and promotes contact between animals and humans and therefore the transmission of zoonoses. In this new episode of The Weather Climate Question, Salomé Robles receives ecologist Philippe Grandcolas, research director at the CNRS.