How will climate change affect our health? Samuel Myers, a senior research scientist in the Department of Environmental Health at Harvard T.H. Chan School of Public Health discussed that issue during a reddit “AMA” (Ask Me Anything) on Friday, October 30. Myers leads a team of researchers in the growing field of planetary health, which focuses on understanding the many ways that human transformation of all of Earth’s natural systems—the climate, oceans, land use, freshwater systems, and other ecosystems—impacts human health.
Here are some of his responses:
What would you encourage us as individuals to do in terms of helping create a sustainable global food system?
As individuals, most of our ability to impact the food production system is through the dietary and purchasing decisions we make. The strongest data supports reducing our consumption of meat, particularly beef and pork. Because most meat production involves feeding grain to livestock, and because the conversion of calories from grain to calories from meat is very inefficient, global meat consumption drives an enormous use of arable land, fossil fuels producing greenhouse gases, water consumption, fertilizer use, etc. If we were to switch to an entirely vegetarian diet, we would increase global caloric supply by 50%, allowing us to feed many more people without increasing our use of resources. Incidentally, reducing consumption of meat, particularly red meat, would provide immediate and significant global health benefits. We can also be cognizant of which fish we eat, using tools like the Monterey Bay Aquarium Seafood Watch tool to avoid threatened species. And being aware of how our food is produced matters as much as which foods we choose to eat. Put simply, we need to produce more nutritious food with fewer environmental inputs. In addition to consuming less meat, we need to waste less food. Roughly 40% of food produced is never consumed. In the developing world, this is because of pre-consumer losses from agricultural pests, spoilage, etc. In the developed world, most of the losses are post-consumer—food that is prepared but not consumed, food that spoils before it gets eaten, etc. Both problems have solutions and implementing them would make an enormous difference in reducing the ecological footprint of global food production.
What do you think are some ways communities can promote a positive impact on local pollinator populations and steps can individuals and communities take to reverse that trend?
There is not an absolutely clear scientific consensus on the causes of pollinator declines, and it is likely that the causes are different in different parts of the world. That said, it is clear that a combination of loss of habitat, loss of forage (food for the pollinators), the use of insecticides, particularly a group called neonicotinoid, and possibly infectious diseases impacting pollinator species are all likely to have a role. In that light, what communities can do to promote pollinators is avoid the use of insecticides as much as possible and try to maintain forage and habitat. Recently the U.S. government announced a significant new program to increase forage and habitat for pollinators providing millions of hectares of land for these purposes. Banning neonicotinoid pesticides would be another positive step. Citizens need to be vocal advocates for measures like these at the local, state, and country level. Hopefully, understanding that there are very significant human health dividends in preserving populations of pollinators will also be motivating. One of the things we did in our recent paper in The Lancet was to analyze and quantify the health benefits in every country of protection of endemic pollinator species. Our goal was to make it clear to policy makers that there are very real health benefits of maintaining robust populations of pollinators within their country.
As climate change kicks into higher gear, will the struggle for diminishing natural resources globally lead to increased acts of aggression?
You are right that climate change, in conjunction with all the other types of global environmental change that are accelerating, has been implicated as a destabilizing influence that could lead to conflict. In fact the U.S. Military has been a leader in analyzing and publicizing this threat to security. There have been some analyses suggesting that conflict correlates with extreme weather, but it is still an area of active research.
Your question touches on an important area of planetary health. In addition to direct health impacts of global environmental change, an extremely important topic is how will multiple types of change alter the habitability of certain regions? For example, how will the combination of growing water scarcity, increased risk of drought from climate change, soil erosion and nutrient depletion, population growth, and higher incidence of natural hazards alter the habitability of parts of sub-Saharan Africa in ways that mean certain populations are, at least temporarily, forced to migrate away? And if a suite of interacting environmental change drives increased migration (which seems quite likely) how will resource-poor populations moving into new areas be received? Will this lead to conflict? In addition to the trauma associated with conflict, we know that migration itself carries significant health burdens from malnutrition, infectious disease epidemics, and psychological and physical trauma. This is an area urgently in need of further work.
Read the full AMA here.
Learn more
Human-wrought environmental changes impacting crops and pollinators could harm health of millions (Harvard Chan School news)