10/10/2016
New research is identifying threats to health and nutrition from the Great Transformation being forced on natural systems
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| Mr. Samuel S Myers - Senior Research Scientist, Harvard School of Public Health |
We have tended to view this Great Transformation of Earth’s natural systems as an environmental problem - a threat to birds and fish, but not so much to us. But increasingly, our group at Harvard is learning that this couldn’t be more wrong.
Recently, for example, we’ve learned that emissions of carbon dioxide into the atmosphere are driving not just global climatic disruption, but also significant reductions in the nutritional value of food. We grew 41 cultivars of rice, wheat, corn, soy, sorghum and field peas in open field conditions in seven locations on three continents over 10 years using free air carbon dioxide enrichment methods. Comparing crops grown at ambient CO2 with those grown under identical conditions but at 550 parts per million (ppm) CO2 (concentrations that our atmosphere is expected to reach in roughly 40 years), we found that the edible portion of the ones grown at elevated CO2 had significant reductions in protein, iron and zinc. This is important because roughly 2 billion people suffer from zinc and iron deficiencies at an estimated cost of 63 million life years lost annually. We also found that 2.75 billion people live in countries whose populations consume at least 70 per cent of their dietary zinc and/or iron from the type of crops showing strong reductions. Additional analyses suggest that these CO2 - induced nutrient changes will drive hundreds of millions of people into zinc deficiency, while exacerbating the condition for billions already suffering from it.
We have also developed a new approach to estimating the importance of animal pollinators for human nutrition around the world, through overlaying data on the pollinator dependence of all food crops, the estimated consumption of each food per capita and the concentration of 23 different nutrients found in each food. Thus we can model how pollinator declines would alter intake of different foods and what these changes in dietary intake would mean in terms of the total amount of a particular nutrient available per capita per country. In research published in January 2015, we showed that pollinator declines would significantly increase the risk of vitamin A deficiency for populations in Mozambique and Uganda, with smaller effects in Bangladesh and Zambia. More recently, we have conducted a global analysis of how such declines around the world would impact the global burden of disease by increasing the risk of vitamin A deficiency, folate deficiency and low intake of fruits, vegetables, and nuts and seeds. In total, we found that pollinator declines could lead to over 1 million deaths annually and a very large global burden of disease.
Loss of animal pollinators is only one of many ways that biodiversity loss is likely to impact human nutrition and health. We also have been investigating an even more direct one-the loss of access to both terrestrial and marine wildlife for food. My colleague Chris Golden has shown that bushmeat is an important source of dietary iron in Madagascar and that removing it from the diet of the population he works with would lead to a 30 per cent increase in anemia in children - an outcome of enormous public health importance as iron - deficiency anemia leads to increased maternal and neonatal death, reduced IQ and reduced work capacity. We are now investigating more comprehensively the role bushmeat plays in the diet as a source of other important micronutrients like zinc, omega-3 fatty acids, and vitamins A and B12. We are concerned that what we are finding in Madagascar is occurring in populations around the world - the quiet erosion of a nutritional cornerstone as access to wild-caught meat becomes scarcer.
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| In total, scientist found that pollinator declines could lead to over 1 million deaths annually and a very large global burden of disease. |
Access to seafood is likely to be of similar, or even greater importance, for coastal populations, and we have started investigating relationships between it, fisheries management, micro- and macronutrient status of local populations and health outcomes. We have put together a strong team of fisheries ecologists, economists and nutritional epidemiologists to begin quantifying the role that global fisheries play in nutrient intakes and nutritional status around the world. In this way, we can explore the extent to which sustainable fisheries management is not just a conservation imperative, but also a public health one.
These issues impact billions of people, but are just the tip of the iceberg. Enormous questions remain: How will the combination of increasing water scarcity, land degradation, pollinator declines, fisheries degradation and climate change interact to alter the quality and quantity of food when we need to roughly double production over the next 40 years? What will be the associated nutritional and health outcomes for different populations around the world? How many people will need to find new homes as a result of changes in climate, food production, natural hazards and sea level?
Such questions are finally beginning to receive the attention they deserve. A group of universities, NGOs and other organizations is coalescing to support the growth of a robust, policy-focused, research field addressing such topics-Health & Ecosystems: Analysis of Linkages (HEAL). It aims to help build a community of practice, identify or construct core educational materials, disseminate research methodologies, provide links to policy communities and communicate developments in the field. In July, 2015, The Lancet will publish a commissioned report of the Rockefeller-Lancet Commission on Planetary Health, detailing the human health risks associated with the accelerating transformation of Earth’s natural systems and emphasizing a set of actions to address them.
The Great Transformation poses a clear and potent danger to human health. It is more important than ever to understand and quantify the relationships between our management of Earth’s natural systems and the health of populations around the world. Only then can we manage them to optimize both health and conservation outcomes for future generations ?
Hoàng Đàn
(UNEP source)
