Michelle Holdsworth is a Professor of Public Health in the School of Health and Related Research (ScHARR), University of Sheffield. She was recently fortunate enough to contribute to the UN Conference on Climate Change (COP21) in Paris in December 2015, alongside other colleagues from the Grantham Centre at Sheffield and the Worldwide Universities Network. They were part of a stimulating panel discussion on the research challenges associated with developing a climate-smart agri-food system, which brought together scientists and social scientists to consider how we may need to adapt the global food system as a result of climate change. Michelle talked about how poor nutrition is linked to climate change.
Unhealthy diets contribute to climate change
The topic of how ‘globalised’ unhealthy diets accelerate climate change is very relevant to work we are doing as part of the Sheffield Institute for International Development (SIID) on changing diets in urban Africa. The food chain contributes around one-third of greenhouse gases emissions from food production (which is the largest source by far), packaging, distribution and retailing; land use for agriculture, transport/travel and waste. Consumer purchasing, cooking, preparation and eating practices also produce greenhouse gases emissions and consumer food practices both drive and respond to the agri-food system.
Diets are changing globally and have done so drastically in most high income countries over the last 50 years. This dietary transition is now happening even more rapidly in most cities of the global south, where people’s habits are changing from a traditional plant based diet (which is often healthier and lower in greenhouse gas emissions) to a diet that is high in processed, energy dense convenience foods (rich in fat and sugar, but poor in nutrients), with widespread consumption of sweetened bottled drinks; which are easily available and cheap, even in the most remote parts of the world. Food of animal origin are introduced and consumption is rising – red meat and animal products are of particular concern for greenhouse gas emissions, as livestock production, especially intensively reared is a major contributor of greenhouse gas emissions. There are co-benefits in changing these practices for both the environment and for people’s health, as they are associated with the rapid rise of diet related diseases such as obesity, diabetes, heart disease and some cancers. Managing these diseases also contributes to greenhouse gas emissions.
Climate change leads to unhealthy diets
Climate change increases the risk and intensity of disasters, such as floods and drought, which are likely to impact on the poorest in low and middle income countries, as a large proportion of the world’s hungry live in climate fragile environments. These climate disasters are most likely to affect those vulnerable already to poor nutrition, which is women and children, leading to food and nutrition crises and further reinforcing the inter-generation transmission of poor nutrition and poverty.
Unless efforts are made to increase climate resilience, then undernutrition could increase by 20% by 2050 according to the IPCC. There is already widespread undernutrition globally without the added challenge of climate shocks in the lives of the poor, with 1 billion suffering from chronic hunger and 2 billion from micronutrient deficiencies (hidden hunger). The consequences of undernutrition on individual mental and physical development are enormous, and this impacts on the ability of a country to reduce poverty.
What can be done to improve diets?
As unhealthy diets are both a cause and a consequence of climate change, any response will therefore require both mitigation (changing diets to reduce greenhouse gas emissions) and adaptation (reducing the vulnerability of societies to climate change). In our research, we focus on mitigating the poor ‘globalised’ dietary habits that are contributing to climate change and diet related non-communicable diseases.
As citizens and food consumers ourselves we can influence the role diets have on aggravating climate change by eating a healthy, sustainable, plant based diet. Whilst there is still debate on what a sustainable diet should look like in different contexts, it seems the following simple steps could go a long way to reducing the contribution of poor diets on greenhouse gas emissions and to poor health.
- Eat lots of fruit and vegetables and starchy staples
- Limit red meat and eat more beans, pulses and nuts
- Eat a varied balanced diet
- Limit energy-dense processed foods, including sweetened drinks
- Eat sustainably sourced fish
- Eat local and seasonal produce
- Limit food waste
Saleswoman in a fruit market in Nairobi, Kenya; source: Biodiversity International
Changes in how society organises the agri-food system are needed to support people to make these changes, such as introducing regulations and legislation like controlling food advertising or fiscal interventions to favour the consumption of healthier, sustainable traditional diets. These can be supported by educational interventions and food provision, for example in schools or workplaces.
We also need to act now to conduct research on preventing the contribution of poor unhealthy diets to climate change. We need to know more about what a healthy and environmentally sustainable diet is in different geographical, cultural and economic contexts globally; and work with nutrition and health ministries to integrate this as part of country specific food based dietary guidelines. We need to find out more about how the transition in diets that we are seeing in cities in the global south impacts on the environmental sustainability of diets so that we can develop a combination of interventions on how traditional eating patterns can be maintained, as this will be more effective than behavioural change interventions after changes to a globalised eating pattern are too widespread.
I discuss some of these issues in greater detail in a recent joint publication with Nicolas Bricas (UNESCO Chair of Global Food systems) on the Impact of Climate Change on Food Consumption and Nutrition in Climate Change and Agriculture Worldwide.
Nicolas works at the CIRAD– the French Agricultural Research and International Cooperation Organization, France. He is collaborating with us on a SIID-funded project on urban diets in Africa in the coming months.