OWNAs biodiversity collapses and disasters linked to climate change increase in intensity around the world, microbiologist Marc-André Selosse, columnist for Pointwant to remain optimistic. For him, natural science is a real guide to inhabiting our world better. Professor at the National Museum of Natural History in Paris and at the universities of Gdansk (Poland) and Kunming (China), he will speak at the Futurapolis Planète forum, in Toulouse, on November 14*.
The main thing is: Will biodiversity and humanity be destroyed?
Marc-André Selosse: No, absolutely not. Despite the collapse of biodiversity and increasingly severe disasters impacting humans on our planet, there are solutions that can be implemented. The problem is that we accept that biodiversity is disappearing, even though this allows our life on earth and the ecosystems that feed us, provide materials or energy, to be easily exploited.
Every time an animal or plant species disappears, its function is lost: pollination or soil fertilization for example. If we replace them artificially, this will cause harm, sometimes to the detriment of our health, just like pesticides. If we don’t act, this will cost us dearly, both in euros and in health.
Blackcurrant pollinators have disappeared, decreasing by 98% in 37 years in Burgundy for example. Today, if we keep osmia, an insect close to bees, which pollinates blackcurrants, we increase blackcurrant production fourfold! Previously it was free, now you have to raise insects… In the United States, in certain areas, there are no longer any bats because they were wiped out by disease from Europe. Since then, farmers have had to use 31% more insecticides because the insects – which the bats feed on – have increased. At the same time and in the same region, a study was published in the journal Science (but controversial, Editor’s Note) establishes just that Infant mortality increased by 8%, mainly due to birth defects and leukemia.
You seem both optimistic and very pessimistic…
I don’t want to be a prophet of doom because I am adamant: there is a solution, by applying the basic rules of ecology to agriculture and animal husbandry. With small short-term investments, we can eliminate long-term problems. But the longer we wait, the more we stabilize patients in advanced critical stages. The evolution of life around us and the disappearance of species will no longer happen. This would not be a problem for the planet, which would always see the emergence of other species much later. But for us, on the scale of human generations, this represents a loss of the tools to better inhabit our world. And an existential threat.
In your work Nature and prejudiceYou develop the idea that the instructions that allow us to live better in our world are there, right before our eyes. What’s that?
The challenge is to pass on to our children what makes the Earth habitable. This “telling” is the science of nature! Or rather our knowledge of biology, obtained thanks to scientific discoveries. This is a continuation of progress! This guide covers the don’ts but also the possibilities. We don’t know all the rules of nature when we start producing food or energy. Therefore, our civilization has separated nature and society, so it does not help us to pay attention to this today. What’s worse, these clear rules were slow to spread and some people thought that what I said was activism. NO ! This is common sense and is the result of the taxes we invest in research. I only think about my child when I have trouble saying it.
Can you give us an example of a simple action to implement?
The most obvious is the return of hedging. They constitute a physical barrier that reduces the flow of disease from one field to another by 84%. This forest is home to birds and bats which act as insecticides, insects, store 100 tons of CO2 per kilometer, help water enter the soil by breaking it up, fight erosion and dry summer winds, and so on.
Hedging will allow the use of pesticides at lower doses. Therefore, what is meant is not “zero pesticides”, but a drastic reduction in pesticides. However, currently, in France, we tear down 25,000 kilometers of fences per year… while our taxes subsidize the installation of 3,000 kilometers. Detractors believe that hedging requires maintenance and reduces production areas: this is true, but we must look further, realizing that we are building a network of nature management. We must take agroecological steps to change the times. We must choose the lever that offers maximum positive consequences.
We need to train a generation that better understands environmental problems.
Investing in the ecological transition is highly profitable if we consider the unlimited costs of adapting to climate change. However, this investment must be collective…
In its report of 16 September 2025, the Court of Auditors explains: every time we invest one euro in the ecological transition, we avoid spending 3 euros tomorrow. And if we do not invest in the ecological transition, we will lose 11.2 GDP points by 2050. Today we see the growth of certain modern diseases that can be linked to pollution or climate change. All of this combined is very expensive, humanly speaking of course, but also within the Social Security budget.
READ ALSO “Heat waves are killers causing billions of euros in losses” Why is the survival of humanity and living creatures not a priority for politicians and citizens?
Some parties often point to lobby groups and political decision makers, who are responsible for all the environmental problems we experience. I do not forget one important fact: citizens, when they buy products or services, choose the mode of production. The products of a highly polluting industry that does not respect our values find buyers in Europe, in France, and this, often out of ignorance, provides support, even justification, for their model.
How to get out of this model?
We clearly need to talk about the problem between adults: this is why I am happy to speak on the Futurapolis forum Pointin Toulouse, November 14*. For the younger generation, we must develop teaching about life sciences and the environment. Currently there is nothing in primary schools and only one hour per week in secondary schools. However, this shows the continuity of our quality of life, this is not a secondary issue!
We must train a generation that better understands environmental problems, especially in the health sector, but also understands that guidance for living things can provide solutions. We believe in chemistry or technology, why not in living things? This can mitigate the side effects of the environmental transformation we are experiencing and that our children will experience.
Some analysts believe that humanity will not change its mind until it experiences an environmental shock, such as the Pearl Harbor environmental disaster. What do you think?
The shock has occurred. The intensity and number of natural disasters are increasing throughout the world. Houses are falling into the sea, 25% of French cities have housing that is uninhabitable due to the shrinkage of clay in the soil during the dry summer. So I don’t believe in raising awareness through drama or collapsology, simply because society is used to disasters. What’s worse, with stress, denial is strengthened, for example about the climate: there are those who deny what we observe or say that it is caused by sunspots…
In a report at COP15 Biodiversity in Montreal in 2022, China’s COP president told us: “ You Westerners will never be able to make real climate decisions in a democracy, it’s impossible. » What inspired this sentence for you?
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Kangaroo today
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This brings us back to Hardin’s tragedy of the commons. This 1960s American ecologist was loathsome, racist, and a proponent of unbridled liberalism, but he was right about one thing: anyone who abuses a problem will soon benefit, and the costs will be paid collectively. Hardin believes that everything should be liberalized so that everyone has a part of nature and does not destroy it. Another solution is to nationalize everything! It is not easy to make ambitious long-term environmental decisions in a democratic country, but if these decisions are taken they will be more profound and effective because they are agreed upon and understood, and not ordered by a State.
* Friday 14 November 2025, at 15.30, at Toulouse School of Economics. Free online registration.
