Why and how land health can prevent a future global pandemic

Nichole Barger is the co-chair of the UNCCD Science-Policy Interface. She holds the post of a Professor in the Department of Ecology and Evolutionary Biology at the University of Colorado at Boulder in the United States. Barger received her Master’s degree from the University of California at Berkeley and holds a Ph.D. from Colorado State University. Barger works as an ecologist to support sustainable land management and restoration of a broad variety of ecosystems throughout the world. Barger was a coordinating lead author on the IPBES global land degradation and restoration assessment. She is also the Research Director of Canyonlands Research Center in southeastern Utah.  In her research program, Barger works in partnership with diverse governmental entities in the U.S. on land degradation and restoration issues such as the ecological risks of fire mitigation treatments, historical drivers and biogeochemical responses to woody plant encroachment, forest decline and regeneration, and more recently restoration of degraded dryland ecosystems with a specific focus on soil ecology. Barger also has extensive research experience working on conservation and management issues in dryland ecosystems across the globe. She has worked with international research teams in the semi-arid grasslands of Inner Mongolia and anthropogenic grassland ecosystems of Venezuela, in addition to work in southern Africa on plant invasions in the biodiversity hot spot of the Cape Floristic region of South Africa and vegetation dynamics of the Namib Desert of Namibia.

January 2021 marked a grim milestone in the COVID-19 pandemic, with over 2 million people dead. Since the new strain of coronavirus (SARS-CoV-2) emerged on the global stage in early 2020, an historical and unprecedented effort has been deployed to quell this global health crisis. As we settle into a new year with increased optimism following the successful development of vaccines against COVID-19, we are turning our sights toward the future, with critical policy questions in mind.

Why are scientists warning about the threats of new pandemics? What structures can we put in place to prevent the next global pandemic? What is the role of land health in preventing future emerging infectious diseases? We have to look into the underlying drivers of emerging infectious disease, of which land health plays a critical role, to find durable solutions. Solutions, that exist, but were, until recently, absent in land use policy, regulatory and management processes.

A recent report released by the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services (IPBES) on the linkages between pandemics and biodiversity looked at this very issue – land health as an underlying driver of global pandemics1. Since 1960, land use change, agricultural expansion and urbanization have driven more than 30% of emerging infectious disease events, according to the Report. An astonishing 70% of human disease originates in animals, which scientists refer to as zoonotic diseases, according to a report by the Food and Agriculture of the United Nations.

In essence, human activities that encroach on wildlife habitat significantly alter the interactions been people and wildlife. Deforestation, wildlife habitat fragmentation and destruction, conversion of land for agriculture or urbanization through increased settlement in wild habitats are some of the most common activities.

These activities bring humans and wildlife into closer proximity, and reduce their “social distance.”  This change in human and wildlife interactions increases the risk of “spillover” events, such that pathogens that reside in animals, such as wildlife or livestock, are then transmitted to a novel host, in this case, humans.

Climate change exacerbates these risks. It alters both human and animal migration patterns and shifts the ranges and life cycles for both the hosts and transmitters. In turn, this multiplies the threat of infectious disease emergence. This means a change in the disease transmission pathways between animals and humans may accelerate or reduce disease risk.

Given that land use change is a key driver of emerging infectious disease risk, where should we focus our land health efforts in preventing future disease outbreaks? What structures are in place already that may be leveraged to prevent future pandemics?

Keeping natural ecosystems intact is widely recognized as a critically important ecosystem service in disease regulation. Thus, disease risk needs to be considered in land regulation and planning processes and in land management and restoration strategies. Yet, it is largely absent.

A first step in any planning process aiming to reduce the risk of infectious diseases emerging is to adopt policies that integrate disease risk assessments and public health impacts into land use planning of major development projects, protected area conservation, and restoration projects. The land degradation neutrality (LDN) conceptual framework provides a structure for integrating disease risk into the land use planning process.

LDN maps three pathways for action. First, to avoid land degradation through regulation and planning. Second, to reduce the impacts of land degradation through sustainable land management strategies. And third, to reverse the effects of land degradation by restoring ecosystems and the services they provide.

Over 120 countries have started setting voluntary LDN targets. This is a ready framework to link to, and integrate, disease regulation and risk.

Integrating disease risk is especially critical in regions of the world that are the most vulnerable to the emergence of novel infectious diseases. Warmer, wetter forested regions containing high levels of wildlife biodiversity while undergoing rapid land use change are at especially high risk of emerging infectious diseases (See Figure 1)4.

Although these factors are predictors of emerging infectious disease risk, the underlying mechanisms by which zoonotic disease transmission pathways are altered by land use change in concert with climate change is still poorly understood.  Increasing financial support and incentives to support disease risk assessment and monitoring and understanding how drivers of land health and climate increase disease risk is critically important, especially in regions that carry the highest risk of emerging infectious disease.

Action on climate change

As move forward to “building back better” in a post-COVID world, it is clear that global monitoring of emerging infectious disease will be a major focus in prevention of future pandemics. Over the next few years, there is a unique and timely opportunity for land health policy and decisions makers, scientists, and educators to engage in the conversation and integration of land health to prevent the emergence of infectious diseases and pandemics in the future.

Figure 1. Relative risk distribution of zoonotic EID events (Source: Allen, T., Murray, K.A., Zambrana-Torrelio, C. et al. Global hotspots and correlates of emerging zoonotic diseases. Nat Commun. 8, 1124 (2017).