Connecting Global Priorities Biodiversity and Human Health

6. CONCLUSION: A THEMATIC
APPROACH TO COMMON
LINKAGES
There is a pressing need to better understand
the relationship between biodiversity and
public health, and this volume seeks to make a
contribution to this imperative. We already know
that biodiversity and corresponding ecosystem
services, and public health intersect on numerous
fronts and these linkages are further explored in
each of the thematic sections that follow.
This demands an understanding of biodiversity’s
fundamental contribution to essential lifesupporting
services, such as air and water quality
and food provision. It also requires mapping the
role of biodiversity in human health on many
other fronts, including nutritional composition;
micro- and macronutrient availability and NCDs;
its applicability in traditional medicine and
biomedical research that relies on plants, animals
and microbes to understand human physiology;
and its relationship with processes affecting
infectious disease reservoirs. We also need to
further explore the role of microbial diversity in
our internal biomes in human health and disease;
the threats of IAS to ecosystems and human
health; the positive feedback loops associated
with climate change; and many other associations.
Our current state of knowledge of these and other
themes is explored in greater detail in each of
the thematic sections included in Part II of this
technical volume.
While there has been considerable scientific
progress in understanding these linkages, much
more interdisciplinary and cross-sectoral work is
needed to assess the full breadth of causal links
between environmental change, biodiversity,
ecosystem processes and services, and the
ultimate impacts on human health, which are
not easily reduced to simple causal chains.
These links are frequently non-linear¹⁵ (Kremen
2005), difficult to predict, and are sometimes
irreversible as biotic–abiotic interactions largely
occur at the level of ecological processes rather
than in the delivery of the services themselves¹⁶
(Carpenter et al. 2009; Mace 2012). The difficulties
inherent in determining these causal links in no
way diminishes the importance of seeking to
identify them.
Understanding the links between the weakening
of ecosystem services and human health is
essential to shaping robust policies, expanding
our scientific understanding of the health needs
of human communities, and to meeting new and
existing challenges to public health in the face of
global environmental change (McMichael and
Beaglehole 2000).
Although the links between biodiversity and
human health are fundamental, they are often
diffused in space and time, and there are a number
of actors that moderate the critical underlying
relationships. To date, work at the biodiversity–
health nexus has been insufficient, which may at
least in part be explained by these diffuse links.
While One Health and similar approaches have
begun to garner greater international acceptance,
the primary focus of interventions in the public
health sector continue to tend toward curative
interventions rather than preventive (upstream)
interventions, which also consider the social and
environmental determinants of health. A powerful
argument can be made for the critical need to
incorporate these dimensions to improve public
health outcomes.
¹⁵ As Carpenter et al. (2009) have noted, some drivers may affect human health without affecting biodiversity or the services
it provides, or some ecosystem processes may affect drivers directly.
¹⁶ This difficulty has been attributed to the fact that causal links can be non-linear or bypass some processes altogether.
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