Katrin Böhning-Gaese, Director and Professor, Senckenberg Biodiversity and Climate Research Centre, Frankfurt University, Germany

Loss of biodiversity

The biodiversity on our planet is declining dramatically. In the first global report of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), published in 2019, the scientific consensus was reached that of the approximately 8 million species currently found on Earth, 1 million species are at risk of extinction (IPBES 2019). There is a particularly high risk in cycads, i.e. palm-like gymnosperm trees, with over 60% threatened species, in amphibians, i.e. frogs, toads and salamanders, with 40% threatened species, and in corals, with almost 40% threatened species (IPBES 2019). In addition, the populations of many species are declining severely. An index that reflects species abundances, the Living Planet Index, shows a decline in species abundance of more than 60% over a 50-year period (WWF 2022). In Germany and Europe, we primarily find steep declines of species diversity and abundances of species in agricultural landscapes, i.e. in fields, meadows and pastures. Abundances of farmland birds in Europe have declined by almost 60% in agricultural landscape over a period of 37 years (Rigal et al. 2023).

In addition to species, natural ecosystems are also disappearing. They are converted into ecosystems used by humans or are increasingly degraded. Half of all ecosystems have already been massively changed. In the last 30 years, the extent of natural forests has declined by an area that corresponds to a total of twelve times the area of the Federal Republic of Germany (FAO 2020). In Germany, only 4% of the previously extensive moors are nature conservation areas (Greifswald Moor Centrum 2022).

Consequences for nature’s contributions to people

The changes in biodiversity have consequences for the contributions that nature makes for us humans (nature’s contributions to people). Biodiversity is the basis of human existence: almost everything that we humans use is provided for by biodiversity. The material contributions of nature include air to breathe, clean drinking water, food, building materials, energy, fibers or medicines, while the regulatory contributions include pollination, seed dispersal and the natural regeneration of forests, the regulation of the climate or the formation of fertile soils. Finally, biodiversity provides a wide range of non-material contributions: beauty, recreation and mental health, spirituality, home and identity. The loss of biodiversity has consequences for nature’s contributions to people. According to scientific consensus (IPBES 2019), of the 27 sub-categories, all but three of nature’s contributions are declining; the only contributions that increase are areas cultivated for food and animal feed, for energy crops (e.g. oil palm) and for materials (e.g. cotton). Ecosystems are obviously managed with a view to some short-term material benefits for humans at the expense of all regulatory and non-material contributions, and even at the cost of other material contributions, e.g. forested land.

Drivers of biodiversity loss

What are the causes of biodiversity loss? There are five important direct causes, the so-called “Big Five,” of biodiversity loss (IPBES 2019). Number one is land use, which is essentially agriculture. The agricultural area is currently massively expanding, especially in tropical countries. Natural ecosystems like forests, savannahs, grassland ecosystems or wetlands are lost and degraded. In Germany and Europe, the reason for the decline in species in the agricultural landscape is very intensive agricultural use, with high application of fertilizers and pesticides, large-scale monocultures, with the disappearance of hedges, trees, little wetlands and fallow areas. Second comes the exploitation of species. Here, marine areas are particularly affected; over 35% of commercially exploited fish stocks are currently overfished (Blue Action Fund 2022). Climate change, pollution and the immigration of so-called “exotic” species are also important. However, behind these direct proximate factors lie indirect or ultimate factors, which cause, e.g. land use change and species exploitation. These include demographic and socio-cultural changes, such as increasing global population, increasing per capita consumption of natural resources and an increasingly meat-based diet. Other factors include economic and technological changes, changes in institutions and governance, conflicts and epidemics. These include, for example, increasing prosperity or the institutional and technical possibilities for global supply chains.

What can be done to bend the curve of biodiversity loss?

From a scientific perspective, it is clear that the loss of biodiversity and its contributions to us humans is already affecting the health, prosperity and well-being of many people. If biodiversity and its contributions to people continue to decline, an ever-increasing number of people will be at risk. But what can we do to bend the curve of biodiversity loss, and to stop further decline in biodiversity and promote biodiversity?

Convention on Biological Diversity

Among the measures of highest importance are international agreements, such as the Convention on Biological Diversity, which was drawn up at the Earth Summit in Rio de Janeiro in 1992 and which 196 nations have signed since. At the 15th Conference of the Parties at the end of 2022 in Montreal, new goals were declared, the Kunming-Montreal Global Biodiversity Framework. These include, among others, the goal of effectively protecting 30% of the land and the sea by 2030, restoring 30% of degraded land and sea by 2030, and promoting sustainable agriculture, forestry and fishing. The great strength of these agreements is that they are international agreements that almost all countries in the world have signed. Hence, these countries have now a moral obligation to implement these goals.

Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)

In addition, international science-policy interfaces play a central role in protecting biodiversity. The corresponding international interface between science and politics for biodiversity is the aforementioned IPBES, the World Biodiversity Council. It is the equivalent of the Intergovernmental Panel on Climate Change (IPCC), which was established for protecting the climate many years earlier. The World Biodiversity Council compiles the state of knowledge and options for action both for individual regions of the world and globally. A key finding of the reports so far is that the protection and promotion of biodiversity can no longer be achieved through individual measures. This means that setting up protected areas or reducing the use of pesticides are good and necessary measures, but on their own will not be enough to conserve biodiversity. Instead, a social-ecological transformation is called for, defined as a fundamental, system-wide transformation of the entire society, i.e. politics, law, business, science and civil society (IPBES 2019).

Future biodiversity scenarios

Further, political and societal decisions can be based on thousands of scientific publications that have examined the influence of humans on biodiversity and the consequences for ecosystems and people. A particularly important role for decision making have publications that use biodiversity models. These models function like the better-known climate models: They are parameterized and validated with existing data and proven relationships; then alternative future scenarios are created. These open up alternative futures that, depending on the measures taken, predict a positive development of biodiversity, a stabilization or a further decline. A particularly comprehensive and ambitious study by Leclère and co-authors (Leclère et al. 2020) reached the conclusion that with a bundle of three types of measures, we can stop the decline in biodiversity by 2030 and increase biodiversity again by 2050. The types of measures are: 1. Large, well-managed protected areas, plus restoration of ecosystems, 2. productive but sustainable agriculture and forestry and more trade, and 3. changes in our consumption and diet towards less food waste and, for countries like Germany, towards a more plant-based diet.

Establishment of protected areas

Hence, the goal of protecting 30% of the land and sea by 2030 is also from a scientific perspective an effective and important goal. However, where and how should protected areas be established and managed? In theory, protected areas should be established in sites with high or unique biodiversity. Nature conservation is important everywhere. However, given that biodiversity is in general much higher in the tropics than at high latitudes, establishing protected areas in tropical regions of South-East Asia, Africa and South and Central America is particularly important. Here, we give recommendations based on a new publication, that supports decision making on-site selection for the Legacy Landscape fund, a public-private initiative that is setting up funds for ideally indefinite funding of large protected areas in low-income countries in the Global South (Voskamp et al. 2023). The decision support tool is drawing on macroecological information on the species richness, endemicity and phylogenetic uniqueness of birds, mammals, reptiles and amphibians, on ecosystem integrity and carbon stocks, as well as on resistance and resilience to climate and land-use change. Most importantly, the tool allows to weight these different criteria, according to individual priorities. Depending whether the priority is, e.g. high biodiversity or high ecosystem integrity, different sites are prioritized. When establishing protected areas in practice, it is of uttermost importance to address each step in a collaborative way, recognizing and respecting the rights of indigenous peoples and local communities over their traditional territories (CBD 2022).

Transformation of agricultural and food systems

In addition, agriculture, at least in Europe, needs to change in a way that allows for more sustainability. As mentioned above, biodiversity is declining severely in agricultural landscapes in almost all European countries (Rigal et al. 2023). Based on a systematic analysis of the situation, including the embeddedness of the agricultural system in the wider political, juristical, economic and societal system, the German National Academy of Sciences, Leopoldina, developed recommendations on how to promote biodiversity in agricultural landscapes (Leopoldina 2020). The most important result was that the decline of biodiversity in agricultural systems can only be stopped with an integrative, systemic approach, considering not only agriculture, but society at large. Agriculture needs to promote productive, but biodiversity-rich, land-use systems. Measures to be taken are a wider distribution of organic agriculture, but also a more biodiversity-friendly conventional agriculture. Important concrete measures are, e.g., growing a wider variety of crops, using less pesticides and less fertilizer, and promoting hedges, trees, fallows, and other structural components. However, these changes need to be supported by the European Common Agricultural Policy (CAP). In the future, the immense number of subsidies needs to be distributed not according to the size of the farm, but according to the common goods the farm provides also for the protection of biodiversity, climate and water. Further changes are the promotion of joint panels for landscape planning, the development of new technologies, e.g. making use of digitization or breeding new crop species, that are more resistant to pests. However, a major problem is that many of these measures will reduce the productivity of the agricultural system. Together with a larger proportion of protected areas, this raises the question, how to provide food for an increasing number of people?

The Leopoldina systems’ analyses demonstrated that a change of the agricultural system is not sufficient to support biodiversity. In the end, the food system needs to be transformed as well. Concretely, there is the need to promote less food waste and, for countries like Germany, a considerably more plant-based diet (Leopoldina 2020). In addition, in trade and retail, biodiversity-friendly products need to be promoted. Labels should provide easy to understand, trustworthy information on the biodiversity footprint of the product.

Reflecting different world views

In addition to transformative change within nations, e.g. Germany, the reflection, recognition and harnessing of different world views, knowledge systems and values are key to foster biodiversity. This became very apparent when developing the framework on which IPBES is basing its understanding of people-nature relationships (Figure 1, Díaz et al. 2015). In the process of developing the framework, it became visible that different people have very different concepts of nature, of nature’s contribution of people and of a good quality of life. While in science, the terms usually utilized are “biodiversity and ecosystems”, “ecosystems goods and services”, and “human well-being”, in other knowledge systems the terms “Mother Earth”, “Nature’s gifts” or “Living in harmony with nature” might be much more adequate. The framework explicitly embraces different disciplines and value systems, including indigenous and local knowledge, when addressing biodiversity and nature’s contributions to people. The framework can be thought of as a kind of “Rosetta Stone” that highlights commonalities between diverse world views, knowledge systems and value sets and seeks to facilitate crossdisciplinary and crosscultural understanding (Díaz et al. 2015).

Recognizing and harnessing different world views

In the next step, different values and valuations of nature were explicitly addressed in a new IPBES assessment, the methodological assessment report on the diverse values and valuations of nature (IPBES 2022). The Values Assessment explores how people across many different regions and social contexts have conceptualised human-nature relationships (Figure 2). Important results of the assessment are: “Key Message (KM)1: The causes of the global biodiversity crises and the opportunities to address them are tightly linked to the ways in which nature is valued in political and economic decisions…”. “KM2: …most policymaking approaches have prioritized a narrow set of values at the expense of both nature and society as well as of future generations, and have often ignored values associated with indigenous peoples’ and local communities’ world views”. “KM7: Achieving sustainable and just futures requires institutions that enable a recognition and integration of the diverse values of nature and nature’ contributions to people”. And, finally, “KM8: Transformative change needed to address the global biodiversity crisis relies on shifting away from predominant values that currently over-emphasize short term and individual material gains, to nurturing sustainability-aligned values across society”.

Shallow and deep leverage points

When approaching transformative change and action, it is helpful to distinguish between shallow and deep leverage points (Meadows 1999). Shallow lever points take hold, among other things, on parameters, for example the toxicity of pesticides. In contrast, deep leverage points address, among other things, world views, knowledge systems and paradigms on which a societal and political system is based. To date, measures taken to protect biodiversity have tended to be based on shallow leverage points, for example the establishment of protected areas or the reduction of pesticides. In contrast, measures that target deep leverage points are very rarely used. Admittedly, these deep leverage points are very difficult to access. Nevertheless, approaches to deep leverage points, to world views, knowledge systems and paradigms, have huge potential to bring about truly deep and sustainable, long-term changes towards better human-nature relationships.

These analyses offer huge promise in transforming not only people-nature systems globally, but especially in cultures that are currently dominated by short-term and individual material gains. They provide visions of a life in harmony with nature, a vision that 196 nations have declared to follow in Montreal 2022, and that consequently each nation, community and individual should aspire to.

References

Blue Action Fund (2022). A Lifeline for the Ocean. Blue Action Fund, Frankfurt am Main, Germany.

CBD (2022): Convention on Biological Diversity & United Nations Environment Programme (18.12.2022). Kunming-Montreal Global biodiversity framework – Draft decision submitted by the President. CBD, Montreal, Quebec, Canada & UNEP, Nairobi, Kenya.

Díaz, S., Demissew, S., Joly, C., …, Larigauderie, A. (2015): A Rosetta stone for nature’s benefits to people. PLoS Biology 13(1): e1002040.

FAO (2020): Food and Agriculture Organization of the United Nations & United Nations Environment Programme. The State of the World’s Forests 2020. Forests, biodiversity and people. FAO, Rome, Italy.

Greifswald Moor Centrum (Aufgerufen am 20.12.2022). Moore in Deutschland. Greifswald Moor Centrum.

IPBES (2019). Summary for policymakers of the global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Díaz, S., Settele, J., Brondízio, E.S., … & Zayas C.N. (eds.). IPBES secretariat, Bonn, Germany.

IPBES (2022) Summary for policymakers of the IPBES methodological assessment report on the diverse values and valuation of nature. Pascual, U., Balvanera, P., Christie, M. …, Vatn, A. (eds.). IPBES secretariat, Bonn, Germany.

Leclère, D., Obersteiner, M., Barrett, M., ... & Young, L. (2020). Bending the curve of terrestrial biodiversity needs an integrated strategy. Nature, 585(7826), 551-556.

Leopoldina (2020): Nationale Akademie der Wissenschaften Leopoldina, Deutsche Akademie der Technikwissenschaften & Union der deutschen Akademien der Wissenschaften. Biodiversität und Management von Agrarlandschaften – Umfassendes Handeln ist jetzt wichtig. Halle (Saale), Germany.

Meadows 1999, Leverage Points: Places to Intervene in a System. Donella Meadows Institute.

Rigal, S., Dakos, V., Alonso, H., …, Devictor, V. (2023) Farmland practices are driving bird population decline across Europe. PNAS 120: e2216573120.

Voskamp, A., Fritz, S.A., Köcke, V., …, Böhning-Gaese, K. (2023): Utilizing multi-objective decision support tools for protected area selection. One Earth 6: 1143-1156.

World Wide Fund (2022) Living Planet Report 2022 – Building a positive future in a volatile world. Almond, R.E.A., Grooten, M., Juffe Bignoli, D. & Petersen, T. (Eds). WWF, Gland, Switzerland.