RESEARCH

The Planetary Health Alliance will not be tasked with carrying out research itself, but will provide: training in planetary health topics, support in using relevant datasets and research methodologies, announcements about relevant new research and job opportunities, an annual convening to share research results and opportunities – all necessary elements for building a cadre of young investigators with the capacity and motivation to break new ground in this field. In addition, the Alliance will support a postdoctoral fellowship, competitively awarded to post-doctoral candidates with outstanding track records within their disciplines and strong capacity to step out of their disciplinary experience to engage in trans-disciplinary planetary health research with PHA-associated faculty.

The Planetary Health Alliance aims to support the ongoing growth of a robust field of research in the following areas.

Disclaimer: the below descriptions are interim copy. If you are an expert in any of the following thematic areas and would be interested in helping us develop fully fleshed descriptions, please reach out to pha@harvard.edu.

 

ECOSYSTEM TRANSFORMATIONS

CHANGES IN THE ABUNDANCE, COMPOSITION, AND DISTRIBUTION OF SPECIES

Biological diversity (biodiversity), which is being lost at a rate unprecedented in human history, underpins many natural systems on which humans depend for health and wellbeing. Depletion of natural resources, pollution, invasive species, climate chance, ocean acidification, and habitat degradation are just some of the factors driving biodiversity loss on a global scale. Changes in biodiversity affect ecosystem structure and function, often posing threats to key ecosystem services. Biodiversity also impacts exposure to vector-borne disease in ways that are inadequately understood.

CHANGES IN LAND USE AND LAND COVER

The conversion of natural habitat to land used for agriculture and industry is occurring on a global scale, driven by an increasing demand for food, animal products, biofuel, and even cosmetics. Habitat conversion alters the structure and function of ecosystems in many ways, including:

  • substantial reduction of biological diversity, and nitrogen and phosphorous deposition from agricultural field runoff.
  • local air pollution and greenhouse gas emissions from land clearing by burning , which is particularly problematic in tropical and subtropical regions where oil palm cultivation is rapidly increasing.
  • soil degradation, causing desertification and contributing to greenhouse gas emissions by eroding soils and releasing stored carbon.
  • impacts on water quality and quantity, and exposure to water-borne and vector-borne disease in ways that are inadequately understood.

NATURAL DISASTERS

Climate change, combined with ongoing changes in land cover, is anticipated to further increase the risk of, and damage from, many extreme events. Globally, twice as many people were affected by natural disasters in the 1990s vs. in the 1980s, and global annual economic losses from extreme events increased 10-fold over the past four decades. Heat waves, droughts, fires, floods, tropical storms, and other natural disasters pose long-term health consequences. Particulate matter from fires reduces air quality and causes morbidity and mortality from cardiorespiratory disease. Flooding can cause biological contamination of water supplies, displacement and trauma. More intense coastal storms, combined with sea level rise and loss of coastal barrier systems (mangrove forests, vegetated dunes, coral reefs, and wetlands), generate a “triple threat” for inhabitants of low-lying coastal areas.  Survivors of natural disasters face serious, yet poorly understood, physical and mental health impacts. It must be a priority to investigate trends in exposure to natural hazards, which populations are most vulnerable, and effective practices for reducing vulnerability.

CHANGING BIOGEOCHEMICAL FLOWS

Agricultural fertilizer and soil erosion have substantially increased levels of biologically available nitrogen and phosphorous in natural systems. Human production of biologically available nitrogen, primarily driven by the synthetic production of nitrogen fertilizer, is now greater than all forms of natural production combined. Flow of phosphorous into the oceans, primarily driven by the use of fertilizer from mines and livestock manure, is roughly three times the preindustrial level. Excess nitrogen decreases plant diversity in terrestrial ecosystems, and the combination of excess nitrogen and phosphorous in water bodies leads to algal blooms and eutrophication.

URBANIZATION

Rapid urbanization is the dominant demographic trend in the 21st century. Urban design must focus on optimizing natural resources and human health. When building and managing cities, it must be a priority to reduce the overall ecological footprints by reducing impacts on biodiversity; air and water pollution; and per capita energy, water, and arable land use. Designing highly efficient cities and simultaneously capitalizing on health co-benefits, such as cleaner air and using physical activity as transportation, could make an enormous positive impact on health. Further research is needed to develop principles of effective sustainable urban design that promote the physical and mental health of urban dwellers while reducing the global ecological footprint of the world’s cities.

CHANGING FOOD SYSTEMS

Global environmental change – particularly climate change, pollinator declines, fishery and wildlife declines, water shortages, and other forms of environmental processes – will pervasively affect our food systems and the ability to provide a growing human population with enough quality nutrition. Research is needed to understand how multiple interacting types of environmental change impact the quantity and quality of food available to different populations around the world. Another important priority is to understand how accelerating changes and losses to many wild and indigenous foods are likely to alter nutritional intake for different populations and affect their health.

GLOBAL POLLUTION

Our management of Earth’s natural systems is impacting air and water quality around the world.  Warmer temperatures associated with climate change increase the formation of tropospheric ozone, a main constituent of smog and contributor to cardiorespiratory disease.  Warmer temperatures and higher atmospheric carbon dioxide concentrations are associated with longer pollen seasons and increased pollen production, intensifying allergic respiratory diseases, such as asthma.  Biomass burning for agriculture in places like equatorial Asia is driving sharp increases in particulate air pollution and associated morbidity and mortality.  In some regions, air pollution has become so pervasive that it obscures the sun, altering regional weather patterns, reducing agricultural yields, and accelerating glacial melting. Man-made pollutants in water bodies pose a threat to drinking supplies. Water-borne pollutants in oceans and terrestrial water systems are also consumed by small organisms and thus enter the food chain.

WATER SCARCITY

Water scarcity is an enormous challenge in many parts of the world, with many of the world’s most important aquifers being drained much faster than they can be replenished. These trends in water availability will have effects on food production systems, water-borne illness patterns, and other water-related diseases.  For example, the aquifer under the North China Plain, where half of China’s wheat is grown, is falling at up to three meters/year, and it is estimated that each year 300 million Indians and Chinese are being fed on fossil water that is not being replenished.  Demographic changes are driving sharp increases in global water demand at a time when climate change promises to increase water scarcity in a variety of ways, including more extreme forms of precipitation, dry areas becoming drier, earlier spring runoff from winter snow pack, loss of glacial contributions to dry-season flow, sea level rise and inundation of coastal aquifers with salt water, and hotter temperatures leading to increased evapotranspiration.  These complex changes in quantity, quality, and timing of water availability, overlaid on significant existing water scarcity and increasing demand, are likely to impact food production, water-borne disease exposure, and water-related diseases.  Changes in land use (e.g., deforestation) also impact water quality and quantity and exposure to water-borne disease in ways that are inadequately understood.  Research to better characterize these challenges and identify approaches to reducing vulnerability is urgently needed.

CLIMATE CHANGE

Climate change, caused by increasing atmospheric concentrations of greenhouse gases, is driven by human activity. Anthropogenic emissions of carbon dioxide, methane, nitrous oxide, and black carbon are primarily responsible for the changing climate. Burning fossil fuels and clearing natural habitats for human use produce the majority of these emissions. Climate change continues to cause glacial melting in Greenland and the Antarctic, rising sea levels, increases in global mean surface temperatures, increases in extreme weather events, and changes in the abundance, distribution, and composition of species. Climate change and the above ecosystem transformations are inextricably connected; as a result, these changes and impacts mutually exacerbate each other.

HEALTH IMPACTS

CIVIL STRIFE AND DISPLACEMENT

We poorly understand the ways in which multiple complex, coincident, and interacting environmental changes will alter habitability and drive population displacement, but these changes are likely to be associated with large burdens of disease and disability. Little is currently understood about how the combination of climatic disruption, natural hazards (e.g., droughts, heat waves, floods, fires, tropical storms), water scarcity, land degradation, and resulting crop and livestock failures may interact to make parts of the world that currently support large numbers of people uninhabitable. How many people are likely to be displaced? What populations are most vulnerable? And when people are displaced (many of them with very few resources) into areas where they may not be welcome, will civil strife ensue? We know that such displacement is associated with sharp increases in infectious disease outbreaks, malnutrition, and physical and mental trauma. What are the best approaches to managing increasing requirements for population movement with the least conflict and health burden?  These types of questions require urgent focus.

INFECTIOUS DISEASE

Infectious diseases like malaria, schistosomiasis, dengue fever, and zika are responsible for large burdens of disease globally and are highly sensitive to changes in environmental conditions, including temperature, soil moisture and precipitation patterns, deforestation, dams and irrigation projects, and others. It’s an urgent priority to better understand how land management practices alter the risk of these diseases in different settings and what types of interventions can reduce exposure to these diseases. Most emerging diseases globally are zoonotic diseases (with both human and animal hosts), and clearer understanding of anthropogenic influences on the emergence of zoonotic diseases (like HIV and Ebola) is another priority in planetary health research. Given the implications for food security and livelihoods, as well as for the state of global biodiversity, animal disease is also an important subtheme of disease ecology in the planetary health research context.

NUTRITION

Much of the global burden of disease is related to inadequate intake of calories, micronutrients, or certain food groups like fruits, vegetables, meats, nuts, and seeds. Additional burden of disease is associated with excessive intake of the wrong foods. Global food demand has never before increased more rapidly, and the biophysical conditions that underpin our global food production system have never been changing so rapidly. As a result, humanity is enormously vulnerable to health impacts from environmental change mediated through changing access to nutrition.

MENTAL HEALTH

A growing evidence base explores the mental health dimensions of global environmental change.  What are the mental/cognitive benefits of exposure to “intact” nature?  What are the mental health costs of environmental degradation?  Are there significant mental health benefits of managing natural systems in particular ways?  Are the mental health burdens associated with reduced exposure to nature fairly distributed across different populations? Better understanding of these issues could meaningfully inform resource management decisions and urban design to mitigate the mental health impacts of environmental change.

NON-COMMUNICABLE DISEASE

Warmer temperatures associated with climate change increase the formation of tropospheric ozone, a main constituent of smog and contributor to cardiorespiratory disease, and are associated with longer pollen seasons and increased pollen production, intensifying allergic respiratory diseases such as asthma. Particulate air pollution is driving increases in cardiovascular diseases and associated mortality. We are also currently experiencing a global epidemic of over-nutrition characterized by excessive intake of the wrong foods – largely driven by inadequate access to fruits, vegetables, fish, and nuts and seeds – resulting in unprecedented rates of obesity, diabetes, and heart disease.

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