Skip Navigation

Center for a Livable Future

 

The Connections between Diet, People and Planet

jhhmp
 

There is mounting evidence that a healthy, sustainable diet protects public health, the planet and our climate. But what, exactly, qualifies as a healthy, sustainable diet? That’s a tall order! A healthy, sustainable diet provides good nutrition and safe food; uses natural resources with a conservation mind-set; aims to reduce the incidence of non-communicable diseases associated with obesity and poor diets; rebuilds and nurtures ecosystems; and, we hope, mitigates climate change.

Climate change is one of the most visible ways that we are witnessing the degradation of ecosystems and the irresponsible use of natural resources—and our global diets are, in part, exacerbating the problems. By shifting our diets toward plants and away from meat—placing more emphasis on the obligation of high-income countries (HIC) to do so, as opposed to putting the onus on low- and middle-income countries (LMIC)—we not only make strides toward improved public health but also take steps toward stewarding the environment and slowing climate change.

In alignment with the EAT Stockholm Food Forum, the Johns Hopkins Center for a Livable Future (CLF) has highlighted some ways that everyone can address health, environment and climate change at the table.

Healthy diets: more plants, less meat and dairy

Many chronic health problems are associated with higher intake of animal products, particularly red meat and high-fat dairy, as well as lower consumption of vegetables, fruit, whole grains and plant-based proteins, such as nuts and legumes. As diets shift toward eating more meat around the world, health consequences will continue to rise. Chronic diseases are expensive to treat, adding a significant burden to stressed healthcare systems. Globally, chronic or non-communicable diseases (NCDs) are the leading cause of death, contributing to 67 percent of all deaths.[i] Chronic diseases are not limited to higher income countries; 80 percent of NCD deaths occur in low- and middle-income countries. Roughly a quarter of these deaths are people under the age of 60, part of the active workforce.[ii], [iii]

Diets that are high in plant-based foods and low in animal-based foods, particularly red and processed meats and high fat dairy, offer significant health benefits, along with climate and other environment benefits, including more efficient use of land, water, nitrogen, and other resources.[iv],[v], [vi] Behavioral campaigns, such as Meatless Monday, can raise awareness of the impacts of dietary shifts, and introduce consumers to plant-based eating patterns through social media, food-service, restaurants and local/regional food policies.

Reduce wasted food for better health, better climate

Globally about 30 percent of the food supply is never eaten.[vii] If all the world’s food losses and waste were represented as a country, that “country” would be the third highest greenhouse gas (GHG) emitter, after China and the US.[viii] Discarding food is akin to discarding all the embodied GHG emissions involved in its production, processing, transportation, cold storage, and preparation. Additionally, when food decomposes in landfills, it generates significant quantities of methane, a GHG that is up to 84 times more potent than carbon dioxide.[ix]

The United Nations Sustainable Development Goal 12.3 calls for cutting wasted food in half by 2030.[x] The United States Environmental Protection Agency and US Department of Agriculture have set the same goal.[xi] Interventions to reduce wasted food in higher‐income countries should focus on the consumer, including expiration date labeling and quality standards, improving shopping/eating practices, and controlling market supply. In lower- and middle-income countries, the greatest need for change is at the production end, including improvements to infrastructure, storage capacity, mechanization, packaging and roads. According to estimates by climate scientists, meeting this goal alone can reduce projected food production-related carbon dioxide equivalents by 22 percent in 2050.[xii]

Can changing diet and reducing waste mitigate climate change?

World leaders have agreed on the goal of keeping average global temperature rise within 2° C above pre-industrial levels in order to avoid the most catastrophic climate change scenarios. Even if this goal is met, climate change is projected to have significant global impacts, many of which will likely continue for centuries.[xiii]

In order to have at least a 66 percent chance of keeping global warming below 2° C, estimates indicate that global greenhouse gas (GHG) emissions from human activities must be kept at or below 21 gigatons of carbon dioxide equivalents per year.[xiv] Under the business‐as‐usual scenario modeled by researchers,[xv] in which global population increases to 9.6 billion and global meat and dairy consumption increases with rising GDP, emissions from food production alone would nearly exhaust the emissions budget in 2050. This projection includes emissions associated with land-use change, such as deforestation. Combined with non‐agricultural sectors, global emissions would greatly exceed 21 gigatons, with severe consequences for people, public health, economies, and ecosystems. Additional studies have demonstrated the need for dietary shifts to mitigate climate change.[xvi] [xvii] [xviii] [xix] [xx]

Food system activities, including producing, transporting and disposing of food, generate up to 30 percent of total global greenhouse gas (GHG) emissions.[xxi] [xxii]Of these sources, livestock production is the largest, accounting for an estimated 14.5 percent of global GHG emissions from human activities, according to the United Nations.[xxiii] Meat and dairy from ruminant animals, such as cattle and goats, are particularly emissions-intensive.[xxiv]

Ultimately, changing the types of foods people eat and how those foods are produced is better for the climate than reducing the distances foods travel. One study from the United Kingdom estimated that avoiding air-freighted and hothouse-grown foods could reduce dietary GHG emissions by 5 percent—compared with a 35 percent reduction from eliminating meat from diets.[xxv] Another study from the US found that avoiding red meat and dairy one day a week reduces GHG emissions more than eating locally every day.[xxvi]

What is the Johns Hopkins Center for a Livable Future doing?


[i] WHO. Health Statistics and Information Systems, Cause-Specific Mortality Global Summary Estimates, Estimates for 2010-2012; http://www.who.int/healthinfo/global_burden_disease/estimates/en/index1.html; Accessed June 24, 2016.

[ii] Alwan, Ala et al.; Monitoring and surveillance of chronic non-communicable diseases: progress and capacity in high-burden countries; The Lancet , Volume 376 , Issue 9755 , 1861 - 1868

[iii] Nikolic I., Stanciole A., Zaydman M., “Chronic Emergency: Why NCD’s Matter,” World Bank Health, Nutrition and Population Discussion Paper (2011)

[iv] Nelson, M. E., Hamm, M. W., Hu, F. B., Abrams, S. A., & Griffin, T. S. (2016). Alignment of healthy dietary patterns and environmental sustainability: A systematic review. Advances in Nutrition: An International Review Journal, 7(6), 1005-1025.

[v] Whitmee, S., Haines, A., Beyrer, C., Boltz, F., Capon, A. G., de Souza Dias, B. F., ... & Horton, R. (2015). Safeguarding human health in the Anthropocene epoch: report of The Rockefeller Foundation–Lancet Commission on planetary health. The Lancet, 386(10007), 1973-2028

[vi] Springmann, M., Godfray, H. C. J., Rayner, M., & Scarborough, P. (2016). Analysis and valuation of the health and climate change cobenefits of dietary change. Proceedings of the National Academy of Sciences, 113(15), 4146-4151.

[vii] Gustavsson, J., Cederberg, C., Sonesson, U., Van Otterdijk, R., & Meybeck, A. (2011). Global food losses and food waste (pp. 1-38). Rome: FAO.

[viii] Food and Agriculture Organization of the United Nations (2013). Food Wastage Footprint: Impacts on Natural Resources. Rome: FAO.

[ix] Allen, M. (2015). Short-lived promise? The science and policy of cumulative short-lived climate pollutants. Oxford Martin School Policy Paper. Retrieved from http://www.oxfordmartin.ox.ac.uk/downloads/briefings/Short_Lived_Promise.pdf

[x] Lipinski, B., O’Connor, C., and Hanson, C. (2016). SDG Target 12.3 on Food Loss and Waste: 2016 Progress Report. Champions 12.3. Retrieved from https://champions123.org/wp-content/uploads/2016/09/sdg-target-12-3-progress-report_2016.pdf

[xi] United States Department of Agriculture (2015). Press release: USDA and EPA join private sector charitable organizations to set nation’s first food waste reduction goals. Retrieved from: https://www.usda.gov/media/press-releases/2015/09/16/usda-and-epa-join-private-sector-charitable-organizations-set

[xii] Bajželj, B., Richards, K. S., Allwood, J. M., Smith, P., Dennis, J. S., Curmi, E., & Gilligan, C. A. (2014). Importance of food-demand management for climate mitigation. Nature Climate Change, 4(10), 924-929.

[xiii] Intergovernmental Panel on Climate Change. (2014). Climate Change 2014–Impacts, Adaptation and Vulnerability: Regional Aspects. Cambridge University Press

[xiv] Rogelj, J., Hare, W., Lowe, J., Van Vuuren, D. P., Riahi, K., Matthews, B., ... & Meinshausen, M. (2011). Emission pathways consistent with a 2 [thinsp][deg] C global temperature limit. Nature Climate Change, 1(8), 413-418.

[xv] Bajželj, B., Richards, K. S., Allwood, J. M., Smith, P., Dennis, J. S., Curmi, E., & Gilligan, C. A. (2014). Importance of food-demand management for climate mitigation. Nature Climate Change, 4(10), 924-929.

[xvi] Hedenus, F., Wirsenius, S., & Johansson, D. J. (2014). The importance of reduced meat and dairy consumption for meeting stringent climate change targets. Climatic Change, 124(1-2), 79-91.

[xvii] Bryngelsson, D., Wirsenius, S., Hedenus, F., & Sonesson, U. (2016). How can the EU climate targets be met? A combined analysis of technological and demand-side changes in food and agriculture. Food Policy, 59, 152-164.

[xviii] Aleksandrowicz, L., Green, R., Joy, E. J., Smith, P., & Haines, A. (2016). The impacts of dietary change on greenhouse gas emissions, land use, water use, and health: a systematic review. PloS one, 11(11), e0165797.

[xix] Jones, A. D., Hoey, L., Blesh, J., Miller, L., Green, A., & Shapiro, L. F. (2016). A systematic review of the measurement of sustainable diets. Advances in Nutrition: An International Review Journal, 7(4), 641-664.

[xx] Röös, E., Bajželj, B., Smith, P., Patel, M., Little, D., & Garnett, T. (2017). Greedy or needy? Land use and climate impacts of food in 2050 under different livestock futures. Global Environmental Change, 47, 1-12.

[xxi] Vermeulen, S. J., Campbell, B. M., & Ingram, J. S. (2012). Climate change and food systems. Annual Review of Environment and Resources, 37.

[xxii] Garnett, T. (2011). Where are the best opportunities for reducing greenhouse gas emissions in the food system (including the food chain)?. Food Policy 36, S23-S32.

[xxiii] Gerber, P. J., Steinfeld, H., Henderson, B., Mottet, A., Opio, C., Dijkman, J., ... & Tempio, G. (2013). Tackling climate change through livestock: a global assessment of emissions and mitigation opportunities. Food and Agriculture Organization of the United Nations (FAO).

[xxiv] Tilman, D., & Clark, M. (2014). Global diets link environmental sustainability and human health. Nature, 515(7528), 518-522.

[xxv] Hoolohan, C., Berners-Lee, M., McKinstry-West, J., & Hewitt, C. N. (2013). Mitigating the greenhouse gas emissions embodied in food through realistic consumer choices. Energy Policy, 63, 1065-1074

[xxvi] Weber, C. L., & Matthews, H. S. (2008). Food-miles and the relative climate impacts of food choices in the United States. Environmental Science & Technology, 42(10), 3508-3513.