How the CNRS plans to reduce its impact on biodiversity

In early 2025, the publication of the CNRS’s first Overall Sustainable Development and Social Responsibility Plan marked a turning point in the organisation’s approach to environmental issues. Henceforth, moving beyond the carbon issue – the CNRS's main concern in recent years – the organisation intends to implement “a systemic and interconnected approach to our actions”, as Antoine Petit, the CNRS Chairman and CEO, explains. “Using his framework means we are also taking into account our impacts on soil and biodiversity, the conservation of water resources, the transition to sustainable food systems, and pollution and waste management.”

Of course, impacts of this kind still need to be actually measured which has now been achieved for biodiversity. A year of collaborative work led by the CNRS’s Environmental Transition Unit (Transversal Steering Support Mission, MTAP) and involving several of the organisation's functional departments plus support from the consultancy firm Utopies, the CNRS has made its first attempt to quantify the impact of its research activities – incorporating all the uncertainties inherent to such an approach – on biodiversity using the Global Biodiversity Score (GBS), a method developed by the Caisse des Dépôts et Consignations (Deposits and Consignments Fund). Certain research institutions, like the universities of Oxford and Utrecht, for example, have used other tools but the CNRS selected the GBS following its own comparative analysis of the existing methods. The GBS can be used to measure the impact on biodiversity on an organisation’s entire value chain in the form of a metric estimated on the basis of monetary values. In this case the metric is the Mean Species Abundance (MSA), an indicator of biodiversity loss per km² based on an organisation’s activities. At the CNRS, the loss is 2 MSA/km² per year which is equivalent to 2 km² of primary forest being converted into a tarmac car park.

So, which factor contributes the most to the CNRS’s impact on biodiversity? Unsurprisingly the answer is purchasing which accounts for up to 97% of this first biodiversity footprint and 85% of the CNRS’s last carbon footprint assessment. Research activities do indeed contribute indirectly to the five main pressures1  exerted on living organisms defined by the IPBES, the equivalent of the IPCC for biodiversity. These are the destruction and artificialisation of natural habitats; the overexploitation of natural resources and illegal trafficking; global climate change; pollution of the oceans, freshwater, soil and air; and the introduction of invasive alien species. The GBS for the CNRS takes all these pressures into account except invasive species. The rest derives from the CNRS's direct impact on its environment, namely its land and property holdings which amount to 1110 hectares on 101 sites across France.

Tangible impacts on human activities

Beyond these figures, the impact on biodiversity of organisations has very tangible consequences for human activities. "The issue of biodiversity is still overlooked'" according to Philippe Grandcolas, an expert associated with this biodiversity initiative and the deputy scientific director of CNRS Ecology & Environment, one of the ten CNRS Institutes. And yet, the decline of biodiversity actually reduces and limits the activities, survival and comfort of Homo sapiens in real terms. For example, the degradation of soil fauna by pesticides leads to a reduction to the capacity of a significant proportion of agricultural soils to retain water or nutrients; the fragmentation of natural habitats brings humans into contact with animals that act as 'reservoirs' for pathogens, thus promoting the emergence of more infectious diseases; or the disappearance of ‘green water’(the majority of atmospheric precipitation absorbed by vegetation) which significantly increases the vulnerability of two-thirds of humanity to water stress. As Philippe Grandcolas regretfully puts it, “the negative externalities of our activities are growing out of all proportion.”

• 1https://biodiversite.gouv.fr/les-5-pressions-responsables-de-leffondrement-de-la-biodiversite

To buck this trend, the CNRS is developing a biodiversity strategy taking into account its global impacts, the enhancement of its sites, and the organisation's influence on society through knowledge dissemination. This strategy focuses primarily on purchasing through the slogan “Buy better”, according to Séverin Baron, the CNRS’s deputy national environmental transition officer and head of the CNRS’s biodiversity initiative1 . The CNRS’s first Overall Sustainable Development and Social Responsibility Plan, published in 2025, posits the implementation of a number of levers that can be adapted to each organisational level to drive the organisation shift towards sustainable scientific procurement. These are sustainable new or second-hand purchases, pooling resources, repairing or giving a new lease of life to equipment, extended guarantees, and training for purchasing staff. This approach was formalised with the publication last year of the CNRS's first plan to promote socially and environmentally responsible purchasing, an initiative welcomed by Philippe Grandcolas. “A major organisation like the CNRS is capable of incorporating environmental costs into its own purchasing, which is a way of being more responsible and setting an example as regards the environment and biodiversity. By making its own contribution, the CNRS will also reap benefits, just like all the other stakeholders, in fact.”

Towards biodiversity observatories

These benefits may derive from the conservation or restoration of biodiversity or relate to other issues like adaptation to climate change and all are core elements of the approach adopted by the CNRS regarding its land and property assets. In this area, the CNRS has produced an atlas that analyses the proximity of its own sites to protected areas. The majority of its sites (71%) are located within 5 km of a protected natural area, with nearly a third (27%) actually situated within an area of this kind like the Luminy campus in the Calanques national park in Marseille. Of course, locations of this kind confer a responsibility on the CNRS in its role managing these sites. Séverin Baron explains that the aim is to “make CNRS sites places for developing knowledge that combine sustainability, the protection of living things and quality of life at work”. 

To achieve this, the CNRS is launching an innovative initiative from spring 2026 which involves its own staff members monitoring the biodiversity on its campuses. This approach was inspired by citizen science and will contribute to two national databases, supported by the VigieNature programme - Propage for butterflies and Florilèges for the flora of urban grasslands. “These databases were selected because they cover a wide range of pressures on biodiversity at our sites,” explains the deputy national environmental transition officer, pinpointing factors like disturbance and trampling, plant protection products, pressure on ecological corridors, climate change and mowing grass.

• 1 Within the Transversal Steering Support Mission's Environmental Transition Unit.

In practice, two or three volunteer staff members will carry out this local monitoring on their sites with support provided by a coordinator. At the end of May, the Gif campus in the Yvette Valley, below the Saclay plateau in France's Essonne region, will be launching the first such biodiversity observatory on its splendid 72-hectare campus, half of which is woodland. The programme will then be rolled out from this pilot site to other volunteer campuses next year.

The initiative gives Philippe Grandcolas renewed hope. The ecologist sees the approach as an opportunity to implement nature-based solutions, as posited by the Priority Research Programme and Equipment1  project, Solubiod2  which considers it a way to “reverse the trend using the power of biodiversity itself, nature-based solutions.” 

• 1These PEPRs were launched in the framework of the France 2030 plan and aim to bolster the position of French research in scientific fields considered crucial to technological, economic, societal, health and environmental transformations.
• 2Led by the CNRS and the National Research Institute for Agriculture, Food and Environment (INRAE).