Environmental challenges

Combatting the depletion of biodiversity: a global challenge 

An estimated 68% of the wild animal species worldwide have vanished since the start of the 1970s1 . And an estimated 30% of living species today are threatened with extinction2. These figures illustrate how fast, and how much, biodiversity is being depleted. The causes of this are many and varied, but a true awareness has arisen of the disruptions that are under way and their environmental, social and economic repercussions. To rise to these challenges, public and private entities are taking action to contribute not just to preserving biodiversity, but also to restoring it.

Published on 22 May 2024


In September 2023, researchers announced that a sixth planetary boundary had just been crossed3. The concept of planetary boundaries, proposed in 2009 by the Stockholm Resilience Centre, lays out thresholds that we must not cross if we want to avoid undermining living conditions on earth4

Biodiversity: a key component in our ecosystems

Among these boundaries, depletion of biodiversity is a key component in keeping the planet liveable for human beings. Some examples illustrate this essential link: almost 75% of the world’s fruit and grain crops for human consumption depend, at least in part, on pollinisers5; and 17% of the consumption of animal proteins depends on fish6. In a completely different field, 11% of medicines regarded as essential by the World Health Organisation come directly from flowering plants. And, given that the vast majority of treatments are of natural origin, loss of diversity is a direct threat to our capacities to produce and innovate in this area. 

Biodiversity also plays a key role in environmental equilibria. “Biodiversity is fundamental to keeping the carbon cycle and the water cycle intact”, pointed out Johan Rockström, Director of the Potsdam Institute for Climate Impact Research7. “The biggest headache we have today is the climate crisis and biodiversity crisis.”8

Indeed, the oceans produce 50% of the oxygen that we use, absorb 25% of our CO2 emissions, and capture 90% of excess heat generated by these emissions9. Both on land and in the sea, biodiversity is key to human activities. As the UN has pointed out, “Coral reefs are among the most ecologically and economically valuable ecosystems on our planet. Covering less than 0.1 percent of the world’s oceans, they support over 25 percent of marine biodiversity and serve up to a billion people with coastal protection, fisheries, sources of medicine, recreational benefits, and tourism revenues.”10 

Human activities and biodiversity

There are several major causes – all linked to human activities – for depletion of biodiversity at a very fast and accelerating pace11:

  • Destruction of habitats by reducing or fragmenting the room and resources that ecosystems need for development;
  • Overexploitation of resources by using more plants and wild species than ecosystems can reconstitute;
  • Climate change, by compromising species’ fitness to survive;
  • Pollution in various forms by driving species to extinction and causing ecosystems to malfunction; and
  • Invasive species, by threating native species, for example in competing for food or spreading disease12 . This phenomenon is exacerbated by human activities, such as increased transport of goods.

How factors in biodiversity depletion are intertwined

Destruction of habitats, often caused by overexploitation of resources, plays a major role. The destruction of the Amazonian forest illustrates a phenomenon on a large scale – that of deforestation. Since the 1990s, 94 million hectares of forests have been lost worldwide (or 2.4% of total forested land). This has been caused mainly by conversion into farmland, as well as mining and forestry activities13. Forests are reservoirs of biodiversity – the Amazon forest alone shelters an estimated one third of the planet’s species14

This example illustrates the interconnexions between the various factors involved in the depletion of biodiversity. The global population has tripled since the mid-20th century, while changes in lifestyles have come with greater resource needs. Each year, Global Footprint Network, an NGO, determines “Earth Overshoot Day”, i.e., the day on which the global population has consumed more resources than the Earth is able to provide in one year. In 2023, that day was 23 August, vs. the end of December at the start of the 1970s and October at the start of the 1990s15.

    Overexploitation of resources is one cause of the destruction of natural habitats. This, in turn, affects climate change via the carbon and water cycles, as well as pollution. And the imbalance caused by these phenomena promotes the proliferation of invasive animal and plant species.

      Reverse the process

      Given the extent of the phenomenon, more and more people are taking action, and not just environmental associations. The private sector has become aware of the consequences of biodiversity depletion for the global economy – depletion that has already cost it more than 5000 billion dollars annually16.

        One source of leverage is “rewilding”, which consists in taking action not only to preserve, but also to reverse the process of biodiversity depletion by “the large-scale restoration of ecosystems to the point where nature is allowed to take care of itself .”17. Rewilding is done by reintroducing animal and plant species in areas where they had vanished or by suspending human activities in a circumscribed territory.

          Initiatives of this type are becoming more than more popular. The European Union, for example, has made them one of the main avenues of its Green Deal. The UK is launching more and more rewilding projects, and in 2023 Norway unveiled a project to rewild a portion of the Arctic archipelago of Svalbard after more than a century of mining there. These projects are based on recreating fully functional ecosystems, while reintroducing endogenous animal and plant species, training in more respectful farming and animal husbandry practices. On top of the ecological and environmental issues involved, most of these programmes also include an economic component with responsible tourism initiatives or support for small entrepreneurs. 

            These are all initiatives that offer a new vision in which human activities and preservation of biodiversity are no longer enemies but allies. 

              1. https://www.worldwildlife.org/press-releases/68-average-decline-in-species-population-sizes-since-1970-says-new-wwf-report 
              2. https://www.iucnredlist.org 
              3. https://www.science.org/doi/10.1126/sciadv.adh2458 
              4.  ttps://www.stockholmresilience.org/research/planetary-boundaries.html 
              5. https://www.fao.org/3/cc5759en/cc5759en.pdf 
              6. https://www.fao.org/3/cc0461en/cc0461en.pdf 
              7. https://www.science.org/doi/10.1126/sciadv.adh2458 
              8. https://www.ft.com/content/f7d26594-a80c-4431-97bb-b90ad2b0eb92 
              9. https://www.un.org/en/climatechange/science/climate-issues/ocean 
              10. https://www.un.org/en/climatechange/science/climate-issues/ocean 
              11. https://www.ipbes.net/news/Media-Release-Global-Assessment 
              12. https://www.eea.europa.eu/publications/the-benefits-to-biodiversity
              13. https://wwf.panda.org
              14. https://www.unep.org
              15. https://www.overshootday.org/newsroom/past-earth-overshoot-days/ 
              16. https://web-assets.bcg.com
              17. https://www.rewildingbritain.org.uk 

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