Biodiversity and Human Health

The right to health is well established as a fundamental right of every human being. Biodiversity and healthy ecosystems are at the heart of the intricate web of life on earth and the processes essential to its survival. Our planet’s biological resources are not only shaped by natural evolutionary processes but are also increasingly transformed by anthropogenic activity, population pressures and globalizing tendencies. When human activity threatens these resources, or the complex ecosystems of which they are a part, it poses potential risks to millions of people whose livelihoods, health and well-being are sustained by them.

Healthy communities rely on well-functioning ecosystems. They provide clean air, fresh water, medicines and food security. They also limit disease and stabilize the climate. But biodiversity loss is happening at unprecedented rates, impacting human health worldwide, according to a  state of knowledge review jointly led by the World Health Organization (WHO) and Convention on Biological Diversity (CBD).

Biodiversity loss can have significant direct human health impacts if ecosystem services are no longer adequate to meet societal needs. Indirectly, changes in ecosystem services affect livelihoods, income, local migration and, on occasion, may even cause or exacerbate political conflict.

The dual challenges of biodiversity loss and rising global health burdens are not only multifaceted and complex; they also transcend sectoral, disciplinary and cultural boundaries, and demand far-reaching, coherent and collaborative solutions, through integrated approaches, including One Health. To address these challenges, the WHO has established a new expert working group on biodiversity, climate change, One Health and Nature-based Solutions in an effort to consolidate knowledge, and evidence, on these interlinkages in line with the aims of the WHO Manifesto for a Healthy and Green recovery from COVID-19.

Biodiversity loss is occurring at an alarming rate, with recent estimates showing that species extinction rates are currently 10 to 100 times higher than the natural baseline, largely due to human activities like deforestation, habitat fragmentation, and climate change. This loss threatens essential ecosystem services, including pollination, soil fertility, and water purification, with direct consequences for human health. For instance, the degradation of wetlands, which filter freshwater, has led to a 35% decline in global wetland coverage since 1970, increasing waterborne diseases and reducing water availability for over 2 billion people.

There is growing concern about the health consequences of biodiversity loss and ecosystem degradation. Biodiversity changes affect ecosystem functioning and significant disruptions of ecosystems can result in life sustaining ecosystem goods and services. Biodiversity loss also means that we are losing, before discovery, many of nature's chemicals and genes, of the kind that have already provided humankind with significant health-sustaining benefits.

Biodiversity serves as the foundation of healthy sustainable food systems. Access to a sufficiency of a nutritious variety of food is a fundamental determinant of health.

The diverse range of plant and animal species, ecosystems, and genetic resources within our environment directly contribute to the availability and nutritional value of our food. By promoting biodiversity in our agricultural practices and food systems, we can ensure the long-term sustainability of our food production while safeguarding human and ecosystem health.

Nutrition and biodiversity are linked at many levels: the ecosystem, with food production as an ecosystem service; the species in the ecosystem; and the genetic diversity within species. Nutritional composition between foods and among varieties/cultivars/breeds of the same food can differ dramatically, affecting micronutrient availability in the diet. Healthy local diets, with adequate average levels of nutrients intake, necessitates maintenance of high biodiversity levels.

A rich biodiversity provides a valuable genetic pool that can be tapped into to develop resilient and sustainable food crops, livestock and marine species harvested for food. This genetic diversity plays a vital role in breeding and developing plant varieties that are resistant to pests, diseases and adverse climatic conditions. By harnessing the genetic potential of diverse crops, we can enhance agricultural productivity and promote crop resilience, ultimately reducing our dependence on chemical inputs and promoting sustainable farming practices. This not only improves the nutritional quality of our food but also contributes to the overall health and well-being of individuals and communities.

Biodiversity is also closely linked to the provision of ecosystem services. Healthy and diverse ecosystems contribute to soil fertility, natural pest control, pollination and water regulation. By preserving and restoring biodiversity in our agricultural landscapes and seascapes, we can enhance the functionality and resilience of these ecosystem services. This, in turn, supports the development of sustainable food systems that are able to produce nutritious food while minimizing negative environmental impacts.

Intensified and enhanced food production through irrigation, use of fertilizer, plant protection (pesticides) or the introduction of crop varieties and cropping patterns affect biodiversity, and thus impact global nutritional status and human health. Habitat simplification, species loss and species succession often enhance community vulnerabilities as a function of environmental receptivity to ill health.

Traditional medicine continues to play a crucial role in healthcare, particularly in primary healthcare settings. It is estimated that 60% of the world's population utilizes traditional medicines. In certain countries, they are extensively integrated into the public health system. Among the various modalities of traditional medicine, the use of medicinal plants stands out as the most prevalent worldwide, both in traditional medicine and complementary medicine practices. Medicinal plants are obtained through wild collection and cultivation, providing communities with natural products that serve medicinal, cultural and even nutritional purposes.

Although synthetic medicines are available for many purposes, the global need and demand for natural products persists for use as medicinal products and biomedical research that relies on plants, animals and microbes to understand human physiology and to understand and treat human diseases. The reliance on natural resources for medicinal purposes highlights the ongoing significance of traditional medicine and the integration of biodiversity in healthcare practices.

It is important to recognize the valuable role that traditional medicine and natural products play in meeting the healthcare needs of individuals and communities worldwide, including for Indigenous peoples and communities in vulnerable settings. Integrating traditional medicine with modern healthcare systems can enhance access to holistic and culturally appropriate healthcare services while also promoting the conservation and sustainable use of biodiversity. By fostering collaboration and understanding between traditional medicine practitioners, biomedical researchers and healthcare providers, we can harness the benefits of both traditional and modern medicine for the well-being of all.

Human activities disrupt biodiversity and ecosystems, affecting their structure and functions. These disturbances alter organism abundance, population dynamics, and ecological interactions, ultimately impacting infectious diseases. Deforestation, land-use change, habitat loss and fragmentation, population growth, climate change, pollution, invasive alien species, migration, trade and other drivers, all play a role in disease patterns. Increased contact between wildlife, livestock and people, lead to increased risk of disease transmission.

Biodiversity plays a crucial role in disease regulation by maintaining balanced ecosystems where no single species dominates. This balance helps limit the spread of zoonotic diseases—infectious diseases that jump from animals to humans. Recent studies estimate that over 75% of emerging infectious diseases, such as Ebola or Nipah virus, are zoonotic and often arise in areas where natural ecosystems have been disrupted by deforestation or land-use change. By maintaining biodiversity, ecosystems can buffer humans from exposure to disease reservoirs, reducing the frequency and spread of pandemics.

Adopting a holistic, inclusive One Health approach is essential. This approach acknowledges the interdependence of human, animal, plant and ecosystem health. By integrating expertise from various fields and sectors, we can address the complex challenges posed by human activities, biodiversity loss and infectious diseases, and ensure a comprehensive and more coordinated response to safeguarding biodiversity, protecting human health and fostering resilient ecosystems.

Biodiversity provides numerous ecosystem services that are crucial to human well-being at present and in the future. Climate is an integral part of ecosystem functioning and human health is impacted directly and indirectly by results of climatic conditions upon terrestrial, aquatic and marine ecosystems.

Marine biodiversity is affected by ocean acidification related to levels of carbon in the atmosphere. Terrestrial biodiversity is influenced by climate variability, such as extreme weather events (e.g. drought, flooding) that directly influence ecosystem health and the productivity and availability of ecosystem goods and services for human use. Longer term changes in climate affect the viability and health of ecosystems, influencing shifts in the distribution of plants, pathogens, animals and even human settlements. In addressing these challenges, there is growing recognition of the potential of ecosystem-based approaches, also known as nature-based solutions, to mitigate and adapt to the impacts of climate change on biodiversity and human health.

Ecosystems such as forests and wetlands act as natural carbon sinks, absorbing CO2 and regulating global temperatures. Forests alone store around 80% of the planet's terrestrial biodiversity and play a vital role in preventing extreme weather events like floods and droughts (IPCC, 2019). The destruction of these ecosystems accelerates climate change, leading to increased heatwaves, floods, and other climate-related health risks, including heat stress, malnutrition, and the spread of vector-borne diseases like malaria and dengue.

The Kunming Montreal Global Biodiversity Framework (Framework), adopted by the fifteenth Conference of the Parties (COP 15) in December 2022, represents a comprehensive and ambitious ten year global strategy for biodiversity conservation and sustainable use, made up of 23 Targets. The Framework recognizes the vital interlinkages between biodiversity and human health, as well as the three core objectives of the Convention on Biological Diversity: conservation of biodiversity, sustainable use of biodiversity components, and equitable sharing of benefits arising from the use of genetic resources. In considering its implementation, the Framework places particular emphasis on implementing a One Health Approach and other holistic approaches grounded in scientific principles, mobilizing various sectors, disciplines, and communities to collaborate to optimally balance and sustain the health of people, animals, plants, and ecosystems. In the Framework, it also calls on countries to ensure equitable access to tools and technologies, such as medicines, vaccines, and other health products derived from biodiversity.

Adopting a holistic, inclusive One Health approach is essential. This approach acknowledges the interdependence of human, animal, plant and ecosystem health. By integrating expertise from various fields and sectors, we can address the complex challenges posed by human activities, biodiversity loss and infectious diseases, and ensure a comprehensive and more coordinated response to safeguarding biodiversity, protecting human health and fostering resilient ecosystems.

1. Promote actions that safeguard biodiversity and improve health

WHO advances policies that benefit both biodiversity and health, including:

• Promoting biodiversity conservation and sustainable management through nature-based solutions that protect ecosystems providing services like water purification, food security, disease control, and climate regulation.
• Integrating biodiversity into public health policies through approaches like One Health, addressing infectious and noncommunicable diseases, food safety, security, and AMR, through a whole-of-government, whole-of-society approach based on equity.
• Reducing pressures on biodiversity by advancing policies that limit harmful agricultural practices, such as the use of pesticides and fertilizers, to protect ecosystems and human health.

2. Build resilient, sustainable health systems that integrate biodiversity

WHO strengthens health systems to withstand biodiversity loss through cross-sectoral collaboration:

• Mainstreaming biodiversity into Universal Health Coverage (UHC) and primary health care (PHC), ensuring health systems depend on ecosystem services like clean water, air, and disease regulation. Collaboration with the WHO Global Centre for Traditional Medicine supports traditional knowledge systems within a rights-based framework.
• Promoting sustainable health practices, including using traditional medicine sustainably.
• Building health system capacity to respond to biodiversity-related risks like zoonotic diseases from deforestation, habitat destruction, and invasive species, while also addressing mental health.
• Supporting cross-sectoral collaboration across health, environment, agriculture and other sectors.

3. Protect human health from the impacts of biodiversity loss

WHO uses One Health to address health risks from biodiversity loss by :

• Assessing health vulnerabilities related to biodiversity decline, such as infectious and noncommunicable diseases, mental health, and nutrition.
• Developing biodiversity-informed public health plans, focusing on root causes and prevention at source, especially zoonotic diseases.
• Strengthening climate- and biodiversity-resilient health systems, promoting nature-based solutions that conserve biodiversity, support climate adaptation, and safeguard health.

4. Partnerships and Awareness Raising

WHO leads efforts to highlight biodiversity's health impacts and advocates for its inclusion in health priorities. In collaboration with sectoral partners, health professionals, Indigenous Peoples and civil society, WHO embeds biodiversity into global health initiatives like UHC and Health for All, including through the biodiversity and traditional knowledge stream of the WHO Global Centre for Traditional Medicine.

In 2023, WHO and PAHO co-hosted the first global workshop on biodiversity, traditional knowledge systems and health, advancing biodiversity-health linkages in policies, with participation from Indigenous Peoples and traditional health practitioners.

5. Evidence and Monitoring

WHO collaborates with the Expert Working Group on Biodiversity, Climate Change, One Health, and Nature-based Solutions to develop evidence-based strategies addressing biodiversity loss and its health impacts. WHO also:

• Develops global evidence summaries on biodiversity and health.
• Assists countries in assessing health vulnerabilities from biodiversity loss, including threats to food security and mental health.
• Monitors biodiversity-informed health policies to ensure human rights, equity, and Health for All are upheld.

6. Capacity Building and Country Support

WHO helps ministries of health address biodiversity-related health risks by:

• Fostering cross-sectoral collaboration, providing training, guidance, and support for biodiversity-informed health policies within a rights-based approach.
• Collaborating with the Nature for Health (N4H) initiative, which tackles biodiversity loss and climate change to prevent pandemic risks at their source, by promoting policies and capacity development aligned with the Kunming-Montreal Global Biodiversity Framework.
• Facilitating knowledge exchange and developing tools to operationalize One Health, integrating environmental determinants into One Health strategies, using a rights-based approach that considers, where applicable, traditional knowledge systems and the rights of Indigenous Peoples.