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France and the nine planetary boundaries
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Biodiversity loss

A global biodiversity crisis, leading to the planetary boundary being exceeded

Biodiversity refers to the variety of the living world organized on three levels (gene diversity, species diversity and ecosystem diversity), as well as the interactions within and between these three levels. This biological diversity is associated with a set of ecological functions that can be used by man to his advantage. These uses are known as "ecosystem services", and include provisioning services (food, water, materials, natural resources, etc.), regulating services (pollination, carbon sequestration, regulation of the water cycle, etc.) and cultural services (recreation, education, etc.). This biological and functional whole ensures the integrity of the biosphere, one of the key factors in regulating the planet's natural balances.

Since the industrial revolution, multiple human-induced pressures have threatened biodiversity : habitat destruction linked to changes in land and sea use; overexploitation of wild species and resources linked to overfishing and deforestation; climate change; water, air and soil pollution, and the introduction of invasive alien species.

In 2019, the IPBES (see glossary) warned that nature was declining "at a rate unprecedented in human history". In 2022, the World Red List (see glossary) of the International Union for Conservation of Nature (IUCN) indicates that of the 150,388 species studied, 42,108 are classified as threatened with extinction. These threats are mainly due to habitat degradation and loss (see glossary). According to WWF's Living Planet 2020 report, "around 9% of the world's 5.9 million terrestrial species do not have sufficient habitat to ensure their long-term survival, and most are condemned to extinction". At the same time, many of the services provided by nature are deteriorating.

Assessing the planet's position in relation to the tipping point formalized by the planetary boundary "Biodiversity erosion" remains a complex task. Two control variables have been adopted by the scientific community: one relates to the genetic diversity of species (extinction rate); the other is measured using the Biodiversity Intactness Index (BII) to monitor the functional diversity of ecosystems and estimate their capacity to provide sustainable services to populations (Table 3).

Table 3: Control variables and planetary boundary for biodiversity loss

Control variables

Thresholds and areas of uncertainty

Global values

Genetic diversity: extinction rate (number of extinctions per million species, per year).

10extinctions per year out of 1million species (10 - 100extinctions per year out of 1 million species)

100 to 1000 extinctions per year out of 1million species (Steffen et al., 2015)

Functional diversity: Biodiversity Intactness Index - BII (abundance of species in an ecosystem compared totheir abundance in the pre-industrial era), inpercent.

Maintain Biodiversity Intactness Index (BII) at 90% (boundary) for biomes (see glossary), large regional areas (e.g. South Africa), major marine ecosystems (e.g. coral reefs - (see glossary) or large functional groups, and do not fall below 30% (boundary).

Global average BII value: 77% (WWF, 2022)

BII estimated at 84% for South Africa only (Steffen et al., 2015)

Source: based on Steffen et al., 2015

The values presented above show that the planetary boundary is well exceeded for both control variables. This means that the rate of biodiversity erosion is increasing rapidly, reaching a level that endangers the health of ecosystems and species.

The reduction or disappearance of terrestrial and aquatic ecosystems, and of animal and plant species, as a direct or indirect result of human activities, represents a major threat to human well-being in all regions of the world, and ultimately to the stability of human civilizations. Indeed, given the complexity of the living world, the extinction of a single species can have cascading effects, leading to the disappearance of other species, disrupting the functioning of ecosystems and ultimately strongly affecting the quality of the services provided by ecosystems to mankind, particularly in a context where climate change is exacerbating the dynamics already at work in terms of biodiversity erosion.

French contribution to exceeding the planetary boundary

The risk of species extinction is increasing in France

The species extinction risk index, based on data relating to the categories of threat to species on the IUCN Red List, enables us to monitor changes in the state of biodiversity (mammals, birds, amphibians, corals and cycads - (see glossary) present in a given territory, using qualitative criteria (population size, rate of decline, geographical distribution). Ranging from 0 to 1, this index reflects the proportion of species expected to become extinct in the near future unless conservation action is taken. The closer the value is to 1, the more likely it is that the populations assessed will become extinct. Conversely, the closer the index is to 0, the more the species concerned are categorized in a status of "minor concern" (no extinction expected in the near future).

Since the end of the 20th century, this index has been rising for all species, all environments and all continents (Figure 6 ). In 2022, the extinction risk index will stand at 0.17 in mainland France, as well as on a European scale, and at 0.28 worldwide. However, the greatest increase between 2000 and 2022 will be in France (+99%, compared with +67% in Europe and +36% in the rest of the world).

Figure 6: species extinction risk index trends between 2000 and 2022

Notes: the species extinction risk index is deduced from the IUCN Red List Index (RLI) (see glossary): (1-RLI). The RLI method can be found on the IUCN website, in particular in Guidelines for the application of IUCN Red List criteria at regional and national levels.
Source: IUCN Red List Index,BirdLife International, Global SDG Indicators Database platform (extracted March 21, 2023).
Processing: SDES, March 2023

The French overseas territories are characterized by their rich biodiversity. In particular, they are home to 4/ 5th s of the endemic species (see glossary) found in France. However, by 2022, more than half of them will have a higher extinction risk index than metropolitan France.

For many of them, the situation has worsened over the period 2000-2022 (Figure 7). The multiple pressures exerted on these often island territories (urbanization, diffuse pollution, invasive exotic species, tourist developments, effects of climate change) may explain this worrying situation.

Figure 7: Species extinction risk index for France in 2022 and trends between 2000 and 2022

*TAAF = French Southern and Antarctic Lands.
Note for the reader: in 2022, Réunion has the highest species extinction risk index (0.44), while Saint-Barthélémy has the lowest (0.01). Over the period 2000-2022, Mayotte saw the greatest increase in this index (178%), while Saint-Barthélémy showed a downward trend (-46%).
Note: the species extinction risk index varies from 0 to 1 (value included in the bars). The closer the value is to 1, the more likely it is that the populations assessed are in a situation likely to lead to their extinction. Conversely, the closer the index is to 0, the more the species concerned are categorized in a status of minor concern (no disappearance expected in the near future).
Source: IUCN Red List Index, BirdLife International, Global SDG Indicators Database platform (extracted March 21, 2023).
Processing: SDES, March 2023

Although it cannot be used to determine whether the planetary threshold has been crossed for France, the species extinction risk index highlights the dynamics of populations and suggests that the risk of biodiversity loss at national level is tending to increase.

For a better understanding of the phenomenon of biodiversity erosion, a second control variable has been defined. It relates to the functional diversity of ecosystems and is measured using the Biodiversity Intactness Index (BII).

Numerous human activities (industrial, urbanization, construction of transport infrastructures, etc.) exert pressures that are likely to affect biodiversity. Mean Species Abundance (MSA) - (see glossary) is an indicator that reflects the average abundance of native terrestrial species (mammals, birds, amphibians, reptiles, invertebrates and vascular plants) in a territory, relative to their abundance in the original, undisturbed ecosystems.

MSA monitoring is based in particular on the GLOBIO model, which assesses the impact of various pressures (land use, road network, fragmentation of natural environments, hunting, atmospheric nitrogen deposition, climate change) on the abundance of original species. For a given territory, the MSA ranges from 0 (ecosystem destroyed) to 1 (undisturbed ecosystem intact). The researchers who developed the MSA transcribed the planetary limit "Erosion of biodiversity" into MSA terms and estimated it at 0.7214.

14 The MSA is a similar indicator to the BII used by the Stockholm Resilience Centre to set a global limit. The MSA calculates abundance on a species-by-species basis, whereas the BII calculates abundance on a species-group basis; furthermore, the BII gives greater weight to species-rich areas and considers more ecosystem types than the MSA. Increases in the abundance of individual species between the reference situation and the impacted situation are ignored in the MSA to avoid the indicator being inflated by opportunistic or generalist species that take advantage of habitat disturbance. A BII of 0.9 (90%) corresponds to an MSA of 0.72 (see page 46 of the report Using planetary bouderies to support national implementation of environment-relate sustainable development goals). The MSA has been used here because the data is more recent and more accessible.

In 2020, while the global MSA was 0.56, that for mainland France was 0.36. Damage to ecosystem integrity, as measured by this indicator, varies from region to region. While some regions, such as Corsica and Provence-Alpes-Côte d'Azur, have values well above the national average (0.54 and 0.46 respectively), others, such as Pays de la Loire (0.25) and Normandy (0.26), are in a much less favorable situation (Map 1).

Map 1: mean species abundance (MSA), by region, in 2020

Note: MSA values range from 0 to 1, with 1 representing an intact, undisturbed ecosystem.
Source: GLOBIO model, Dutch Environmental Assessment Agency, 2022. Processing: SDES, September 2022

On a metropolitan scale, the loss of biodiversity integrity is estimated at 61% for vertebrates in 2020 (1- 0. 39 where 0.39 is the MSA) and 70% (1- 0. 30) for plants. Land use is the dominant pressure contributing to the loss of species abundance in both vertebrates (- 0. 36) and plants (- 0. 57). Road network disturbance (- 0. 12 for vertebrates) and climate change (- 0. 05 for vertebrates and - 0. 09 for plants) also affect this index (Figure 8).

Figure 8: Pressures contributing to the loss of mean species abundance (MSA), mainland France, 2020

Source: GLOBIO model, Dutch Environmental Assessment Agency, 2022. Processing : SDES, September 2022

Data for French overseas territories remains patchy, with the exception of French Guiana. For this territory, over 90% of which is primary forest, the MSA is around 0.73, corresponding to a state close to that of an undisturbed ecosystem. Hunting (- 0. 24) and aerial nitrogen deposition (- 0. 11) are the main pressures contributing to the loss of MSA for vertebrates and plants respectively.

What is the trend of mean species abundance in France?

In its 6th Assessment Report on Climate Change (2021), the IPCC examines several socio-economic scenarios15 (SSP- Shared Socio-economic Pathways) integrating demographics, education, urbanization and gross domestic product (GDP) to sketch out different possible futures.

Each of these scenarios shows, in different ways, that biodiversity is affected, particularly in terms of species abundance. Thus, by 2050, according to scenario SSP1 ("optimistic" scenario), the MSA of mainland France would increase and could reach 0.40, i.e. an 11% increase on its 2020 level. Conversely, in the case of scenario SSP3 (the most "pessimistic" scenario), the MSA would fall (0.34, i.e. a 6% decline). Scenario SSP5 would have no direct impact on the evolution of the MSA (Figure 9).

15 "Optimistic" scenario (SSP1): a world characterized by high investment in education and health, rapid growth and optimally functioning institutions that prioritize the development of more sustainable practices.
- "Pessimistic" scenario (SSP3): limited investment in education or health, rapid population growth and growing inequality, as well as policies with little concern for the environment and more focus on regional security and industrial production.
- SSP5 scenario: rapid growth, based on high fossil fuel consumption, with a rise in living standards and, in particular, a fall in extreme poverty, which would, on the other hand, increase the ability to adapt.

Figure 9: Mean species abundance trend, mainland France, to 2050

Notes: MSA values range from 0 to 1, with 1 representing an intact, undisturbed ecosystem; SSP1, SSP3, SSP5: Shared Socio-economic Pathways(SSP) scenarios examined by the IPCC in its 6th Assessment Report (2021) to sketch out different possible futures.
Source: GLOBIO model, Dutch Environmental Assessment Agency, 2022. Processing: SDES, September 2022

The values presented for France show that the planetary boundary for "Biodiversity loss" is largely exceeded with regard to these two control variables. The analysis also shows that climate change is likely to make the situation even worse.

POLICIES AND ACTIONS IN FAVOR OF BIODIVERSITY

At the 15th Conference of the Parties to the Convention on Biological Diversity in December 2022, governments adopted a new global framework for biodiversity. This defines a trajectory for achieving the Convention's main objective of "living in harmony with nature" by 2050. The European Union (EU) and France also have biodiversity strategies for 2030, which contribute to the implementation of this global framework.

Pressure reduction

The primary aim of biodiversity protection policies is to reduce the pressures threatening biodiversity. IPBES (2019) has identified the following five main pressures, for which examples of associated public policies are given:

  • Land use change is the primary pressure on terrestrial ecosystems (IPBES). Related policies are dealt with mainly in the fact sheet dedicated to land use change, pp. 40-43. Urban development planning tools, such as SRADDETs and local urban development plans (PLUs), are one of the main levers for regulating this pressure. Implementation of the "avoid-reduce-compensate" sequence16 should also help to achieve the objective of no net loss of biodiversity, by minimizing the residual impact of development projects subject to impact assessment.
  • Direct use of organisms: at international level, trade in endangered wild species is governed by the CITES17 Convention, adopted in Washington in 1973. In France, under article L.411-1 of the Environment Code, the direct exploitation of certain species may be prohibited on the grounds of their ecological, scientific or heritage interest. As the IPBES points out, direct harvesting is the main pressure on marine ecosystems, particularly through professional sea fishing. This practice is regulated at international level by regional fisheries management organizations, such as the International Commission for the Conservation of Atlantic Tunas, and at European level by the Common Fisheries Policy.
  • Pollution: in the agricultural sector, for example, numerous pesticides have been successively banned (DDT18, atrazine, chlordecone, etc.), and the Ecophyto II+ plan aims to accelerate the withdrawal of the most worrying substances and to accompany the phasing-out of glyphosate.
  • Climate change: the public policies associated with this limit are covered in the dedicated fact sheet (see "Climate change" limit pp. 24-28).
  • Invasive alien species (IAS): at European level, the fight against IAS is framed by the October 22, 2014 regulation on the prevention and management of the introduction and spread of invasive alien species. Within this framework, France has adopted an action plan in 2022 to prevent the introduction and spread of IAS, accompanied by a program of 500 "one-two punch " actions to be implemented between 2022 and 2025.

16 The "principle of preventive and corrective action" was introduced into Article L110-1 II2 of the French Environment Code in 2010 with the Grenelle law, then clarified in 2016.
17 Convention on International Trade in Endangered Species of Wild Fauna and Flora, known as CITES, or Washington Convention.
18 Dichlorodiphenyltrichloroethane.

Achieving good conservation status for habitats and species

Biodiversity protection policies are also dedicated to protecting specific ecosystems or species. At European level, these include the "Birds" (1979, revised in 2009) and "Habitats-Fauna-Flora" (1992) directives, which aim to ensure the good conservation status of species and habitats of Community interest. To achieve these objectives, these directives establish a network of ecological sites known as "Natura 2000", as well as national action plans dedicated to species of community interest. The Water Framework Directive (2000) and the Marine Strategy Framework Directive( 2008) aim to achieve good ecological status for continental and marine aquatic environments. Within this framework, successive cycles of implementation, combined with programs of measures, contribute to improving the ecological status of these environments, as well as the conservation status of associated species (see glossary), notably by reducing the pressures that threaten them.

One of the main tools for achieving good ecological status for ecosystems and species of interest today is the development of the network of protected areas. The second target of the new global framework for biodiversity is to reach 30% of protected areas by 2030. In France, the national strategy for protected areas (2022-2030) sets an even more ambitious target: 30% of protected areas by 2030, with one-third under strong protection. The target of 30% of protected areas has almost been reached, and the network of high-protection areas is currently being rolled out.

The Global Biodiversity Framework also calls for the restoration of 30% of degraded environments by 2030. The European regulation on nature restoration should help to make this objective operational, by setting restoration targets for each environment.

Mobilizing the company

One of the main challenges of the national biodiversity strategy is to raise awareness and mobilize society to protect biodiversity. To this end, local authorities can undertake the creation of a local biodiversity atlas, involving all local stakeholders. Participatory science (see glossary) is another important way of raising awareness of the need to protect biodiversity.

Property owners can also contribute to the protection of biodiversity by entering into real environmental obligations, the purpose of which is to maintain, conserve, manage or restore elements of biodiversity or ecological functions. These obligations, which can last up to 99 years, also apply to subsequent owners of the property.

Voluntary schemes also enable companies and local authorities to make a commitment to protecting biodiversity. This is particularly true of the "Entreprises engagées pour la nature" (Companies committed to nature) and "Territoires engagés pour la nature" (Territories committed to nature) programs, which support companies throughout their value chains and in their investment decisions. These programs, run by the French Office for Biodiversity (OFB), currently involve 89 companies and 451 territories19.

19 Figures consulted on the website "Engagés pour la nature : et si vous passiez à l'action", OFB, January 18, 2023.

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