Species extinction “is serious because we are nothing without biodiversity” but it’s still “reversible”, explained on Wednesday January 12 on franceinfo Bruno David, president of the National Museum of Natural History (MNHN), after the study of an international team of researchers which indicates that if we take into account non-vertebrates to measure the rate of species extinction, the situation is alarming.
franceinfo: Usually we talk about vertebrate animals when we talk about extinction. Why ?
Bruno David: Because they are the easiest animals to observe, so most indicators, the oldest, relate to vertebrates. All the other animals are more discreet, we see them less well, so our indicators are more recent but we continue to build them and this is what allows us to draw this trend.
What does this study show?
This tells us that we could have around 10%, 15%, maybe 20% species extinction in the decades to come. There are declines in abundance, that is to say that there are fewer and fewer individuals within certain species and this could end in extinctions. Scientifically, we have to ask ourselves how we are positioning ourselves on a trend that is taking us towards a sixth extinction. How many species could go extinct? If we compare this to the great crises of the Earth’s geological past where 80% had died out, we can say that it is not so serious. But that’s not what I’m saying because we’re going 100 to 1,000 times faster on this trajectory than ever before in the Earth’s geological past. So maybe we are at the beginning of an extinction phase but we are getting into it very, very quickly and that means we have to react quickly and now.
Do we need these species?
This is serious because we are nothing without biodiversity. We only digest, we only eat, we only breathe thanks to biodiversity. The services rendered by biodiversity are gigantic and we are one species among millions of other species and we are nothing without the others.
Are human activities responsible for these declines?
Yes, all the human activities that can result in the overexploitation of spaces on the continents, the exploitation of resources, pollution, the movement of species that become invasive and we add climate change to all that. We are faced with something multifactorial even if it is due to us, Homo sapiens. It’s a bit the same situation as in the crises of the Earth’s geological past where they were all multifactorial. There is an advantage and a disadvantage is that we are the origin of the problems, which is annoying, but as we are the origin of the problems we are also the origin of the solutions.
Can we really improve things?
It is reversible as long as it has not exceeded a certain threshold. This threshold will not be reached overnight, it will be done piece by piece until the Earth becomes more difficult for us to inhabit. Our societies have been settled on a relatively stable planet for millennia and they are adapted to this stability. If we destabilize these systems, our societies will suffer first. I am not worried about the future of life on Earth but about the future of our society and the future of a species called Homo sapiens.
Which species have disappeared?
There are butterflies that have disappeared, snails, small sea creatures, many organisms, species that have already disappeared. What worries me are these declines in abundance, it is what precedes extinctions. If we do nothing it will result in extinctions. To prevent an extinction, all that is needed is to reduce the pressure exerted on ecosystems and biodiversity. Let’s transport less species, pollute less, try to artificialize spaces on the continents less, take fewer resources from the ocean, avoid too much climate change and everything will be better. The wisest solution is therefore to change our behavior and we have a significant margin for progress without restricting ourselves beyond a certain limit. The most important progress can be made in the worst situations because that is where there is the greatest margin. It’s high time because biodiversity is resilient, so let’s trust it.