Long considered the poor relation of ecology , biodiversity, which plays an important role in human life, is a very worrying subject. Indeed, biodiversity is undergoing a rapid deterioration that weakens it a little more every day. Why is it in danger? And above all, what can we (still) do?
What is biodiversity?
Behind the word diversity lies the set of all varieties of all living species and ecosystems in the world. This refers to life in all its forms: animals, plants and micro-organisms whether terrestrial, aquatic, marine, of all species, of all organizations. These living organisms interact with each other and are at the origin of an incalculable number of reactions necessary for life. Each one plays a specific function within its ecosystem and thus guarantees the balance of all populations.
Precious ecosystems above all
A pond or a forest, for example, are ecosystems where living things are organized by offering a place to everyone, where the food chain benefits everyone and where all forms of life are represented. The more organisms there are in an ecosystem, the more prolific nature is, and the more inert resources can be transformed into organic resources. But the opposite is also true: the less biodiversity there is, the less favorable the ecosystems are.
Crucial importance for life
We know how much the disappearance of an animal disrupts the food chain. It is exactly the same for biodiversity. Constantly turning over the land and treating it with chemical fertilizers impoverishes the soil. Microorganisms and earthworms can no longer decompose or recycle organic matter. As a result, soil fertilization and soil aeration decrease, which promotes water absorption. Gas exchanges will no longer be able to take place and plants will not be able to develop naturally. Indeed, soil rich in living beings gives soil rich in nitrogen, an essential element for crops, which is replaced by artificial fertilizers when the soil lacks it.
An invaluable balance
Problems always arise when an action disrupts the balance. If we cut down trees that shelter families of insects or chimpanzees, the latter will die for lack of a habitat. Another example is the disappearance of bees: these insects deposit male pollen on female flowers, without them it is the reproduction of flowers, and therefore the fruits, which is disrupted.
Marine biodiversity is also vital
On the sea side, plastic pollution or large-scale pollution produce dead zones and lead to the disappearance of plankton. While plankton feeds many species, it also produces the oxygen that we breathe. Indeed, the microorganisms that constitute it absorb carbon dioxide and release oxygen: it is the same photosynthesis phenomenon as that of forests. In fact, everything is linked. And if nature nevertheless manages to keep its active systems by adapting, its backup systems are undermined. This is when entire chains of co-dependencies disappear, with, in their wake, many mechanisms that are essential for humans.
Invaluable benefits
We can imitate nature, try to repair it, but replacing its effects is impossible. However, biodiversity is what allows us to eat, live, breathe... The multiple benefits offered to humans by a rich and preserved biodiversity are the result of complex exchanges and interactions between all its actors, however microscopic they may be. This perfect balance of the earthworm that aerates the earth while allowing it to receive rainwater to water the roots of the plants cannot be recreated artificially. Artificial dikes are extremely expensive and are never as effective as tree roots in retaining the soil in the event of flooding. If these "services" provided by biodiversity were paid for, we can bet that nature would be better protected, simply to save money!
What threatens biodiversity?
Everything! Since living things are everywhere, anything that destabilizes ecosystems threatens biodiversity : pollution of the air, soil and seas, but also destruction of natural habitats due to urbanization, disappearance of forests, ice floes, etc. On the animal side, the poaching of endangered species is of course fraught with consequences, as are the chemicals that kill insects that are nevertheless terribly useful.
When conditions change too quickly, species disappear because they have not been able to adapt to their new living conditions. This was already the case in the time of the dinosaurs. Today, climate change is pushing animal populations to move to escape the heat, encroaching on the territories of other species. This is the case on land but also in water where warming will allow certain species that love the heat to develop: the loss of biodiversity then comes from the overpopulation of a species that spreads over a territory to the detriment of everything else, or whose evolution becomes out of control. Mosquitoes, for example, are very sensitive to variations in temperature and humidity and certain species that carry diseases contaminate new human populations by moving with the heat.
Pollution and global warming
Biodiversity is in danger when certain animal or plant populations are wiped out, but also when the balance of one of its ecosystems is no longer maintained. However, pollution and global warming are the two levers that have a terrible influence on ecosystems and put them to the test. Most of the dangers today are "anthropogenic", that is to say due to human activities that pollute, overexploit natural resources, destroy ecosystems and the habitats of animals that then have no chance of survival. Climate disruption linked to human activities that aggravate the greenhouse effect is one of the major dangers for biodiversity. Indeed, the climate has always been the number 1 factor in the appearance, evolution or disappearance of species. It is the climate that regulates or triggers the transformations of living things.
The accumulation of imbalances
Biodiversity can suffer several imbalances at once. For example, green algae on the coasts of Brittany invade the coastline and prevent other species from existing. If they have multiplied so much, it is because of the intensive pig and poultry farming in the region. This type of farming drastically increases the nitrate level of the water which emits phosphorus and nitrogen which they love. Indeed, not only does intensive farming use nitrate as a fertilizer for its agriculture but it also produces it through the droppings of farm animals which are also rich in nitrate. The problem arises when these green algae washed up on the beaches release hydrogen sulfide which can be fatal. An environmental and human disaster.
An unprecedented collapse of life
On a global scale, each species is more or less destined to disappear one day… but this generally takes several million years. The problem that makes protecting biodiversity so difficult today is the scale and speed of the species extinction process. Life on Earth has already almost disappeared 5 times because of environmental changes… but over a period of several million years! Today, for the first time, the disappearance of biodiversity has never been so rapid, which gives a feeling of helplessness. Such a collapse of life has never occurred in the entire history of humanity.
- According to the IPCC on biodiversity (equivalent to the Intergovernmental Panel on Climate Change), one million animal and plant species are threatened with extinction in the coming decades.
- Fish, mammals, reptiles and amphibians have never declined at such a rapid rate, a hundred to a thousand times higher than that calculated over geological time, says the WWF.
- Over the past forty years, 60% of vertebrate populations have disappeared.
- According to the latest report from the National Diversity Observatory, only 20% of remarkable ecosystems are in a favorable state of conservation.
- In France, over the last ten years, the bird population, a representative indicator of overall biodiversity, has fallen by 40% for goldfinches and by a third for birds living on agricultural land.
Why can't we go back?
The alterations of biodiversity are irreversible: extinct species will remain so, territories laid bare by mining or logging will never find virtuous soil again, the Great Barrier Reef will only be able to survive. Indeed, the disappearance or alteration of animal or plant species in an environment that retains its characteristics could see them return. Even if it means giving them a helping hand, as we try to reintroduce certain species. But today, ecosystems have for the most part lost the characteristics that allow them to accommodate life. The functioning of the oceans is altered by their acidification and plastic pollution is endemic there.
How to slow the disappearance of biodiversity?
It is estimated that it will take a century to dissipate greenhouse gases: if we stopped ALL CO2 and methane emissions today, we would gain nearly 1°C by the end of the century. A small degree that seems small but a huge variation for the coldest and warmest regions, or a degree of difference represents a real upheaval for the environment: within 1°C, the ice melts or does not melt, for example… However, the extinction of species since 1900 has never been at such a rate, representing a major biological crisis. In addition to decimating species and ecosystems without equivalent, globalization, international transport, imports and exports leave no chance for nature to be able to reconstitute what is destroyed. If we cannot stop it, we can nevertheless have our foot constantly on the brake from now on in the hope of slowing down the carnage.
Promoting biodiversity to preserve it
This is an interesting avenue to explore: beyond legal texts, beyond citizens' resistance to lobbies, beyond ecological public policies, inestimable biodiversity should be valued more in order to be preserved. Giving a financial value to biodiversity would make it possible to show (to major polluters in particular) the cost, with supporting figures, of its damage. This new tool could thus integrate ecology into the costing of projects. If we calculated the damage of each project destroying biodiversity (destruction of hectares of forest to build a hotel complex for example), we could envisage a compensation system. An idea that is starting to gain ground.
Act for local biodiversity
But in the meantime, we can change our consumer choices to avoid products whose manufacturing is very harmful to the planet: say goodbye to fast fashion and its toxic waste dumped into waterways, boycott palm oil from deforestation that is causing treasures of tropical biodiversity to go up in smoke, stop the plastic that is swarming in the sea. We can also act locally to protect the fauna and flora of our regions, sow flower seeds to help bees, promote permaculture and soil preservation, organize cigarette butt collections. All these actions in favor of nature contribute to saving what can still be saved.
Biodiversity is us and everything around us, from the smallest to the largest, and each living organism has a function in the greater whole. When we talk about "protecting nature", we are talking about biodiversity without really knowing it. Mobilizing for nature means mobilizing for us because no life is possible without biodiversity. Now is the time to move towards more virtuous practices and to respect the environment.
Biodiversity is irreplaceable, what would life be like if water was no longer drinkable, if there were no more fish in the sea?
