Tara Garnett

Sustainable Intensification in Agriculture: Premises and Policies

Clearer understanding is needed of the premises underlying SI and how it relates to food-system priorities. Food security is high on the global policy agenda. Demand for food is increasing as populations grow and gain wealth to purchase more varied and resource-intensive diets. There is increased competition for land, water, energy, and other inputs into food production. Climate change poses challenges to agriculture, particularly in developing countries (1), and many current farming practices damage the environment and are a major source of greenhouse gases (GHG). In an increasingly globalized world, food insecurity in one region can have widespread political and economic ramifications (2).

Public health benefits of strategies to reduce greenhouse-gas emissions: food and agriculture

Agricultural food production and agriculturally-related change in land use substantially contribute to greenhouse-gas emissions worldwide. Four-fifths of agricultural emissions arise from the livestock sector. Although livestock products are a source of some essential nutrients, they provide large amounts of saturated fat, which is a known risk factor for cardiovascular disease. We considered potential strategies for the agricultural sector to meet the target recommended by the UK Committee on Climate Change to reduce UK emissions from the concentrations recorded in 1990 by 80% by 2050, which would require a 50% reduction by 2030. With use of the UK as a case study, we identified that a combination of agricultural technological improvements and a 30% reduction in livestock production would be needed to meet this target; in the absence of good emissions data from Brazil, we assumed for illustrative purposes that the required reductions would be the same for our second case study in São Paulo city. We then used these data to model the potential benefits of reduced consumption of livestock products on the burden of ischaemic heart disease: disease burden would decrease by about 15% in the UK (equivalent to 2850 disability-adjusted life-years [DALYs] per million population in 1 year) and 16% in São Paulo city (equivalent to 2180 DALYs per million population in 1 year). Although likely to yield benefits to health, such a strategy will probably encounter cultural, political, and commercial resistance, and face technical challenges. Coordinated intersectoral action is needed across agricultural, nutritional, public health, and climate change communities worldwide to provide affordable, healthy, low-emission diets for all societies.

Food security and sustainable intensification

The coming decades are likely to see increasing pressures on the global food system, both on the demand side from increasing population and per capita consumption, and on the supply side from greater competition for inputs and from climate change. This paper argues that the magnitude of the challenge is such that action is needed throughout the food system, on moderating demand, reducing waste, improving governance and producing more food. It discusses in detail the last component, arguing that more food should be produced using sustainable intensification (SI) strategies, and explores the rationale behind, and meaning of, this term. It also investigates how SI may interact with other food policy agendas, in particular, land use and biodiversity, animal welfare and human nutrition.

Plenary Lecture 3 Food and the planet: nutritional dilemmas of greenhouse gas emission reductions through reduced intakes of meat and dairy foods

Legally-binding legislation is now in place to ensure major reductions in greenhouse gas emissions in the UK. Reductions in intakes of meat and dairy products, which account for approximately 40% of food-related emissions, are an inevitable policy option. The present paper assesses, as far as is possible, the risk to nutritional status of such a policy in the context of the part played by these foods in overall health and well-being and their contribution to nutritional status for the major nutrients that they supply. Although meat may contribute to saturated fat intakes and a higher BMI, moderate meat consumption within generally-healthy population groups has no measurable influence on morbidity or mortality. However, high consumption of red and processed meat has been associated with increased risk of colo-rectal cancer and recent advice is to reduce intakes to a maximum of 70 g/d. Such reductions in meat and haem-Fe intake are unlikely to influence Fe status in functional terms. However, overall protein intakes would probably fall, with the potential for intakes to be less than current requirements for the elderly. Whether it is detrimental to health is uncertain and controversial. Zn intakes are also likely to fall, raising questions about child growth that are currently unanswerable. Milk and dairy products, currently specifically recommended for young children and pregnant women, provide 30-40% of dietary Ca, iodine, vitamin B12 and riboflavin. Population groups with low milk intakes generally show low intakes and poor status for each of these nutrients. Taken together it would appear that the reductions in meat and dairy foods, which are necessary to limit environmental damage, do pose serious nutritional challenges for some key nutrients. These challenges can be met, however, by improved public health advice on alternative dietary sources and by increasing food fortification.

Global and regional health effects of future food production under climate change: a modelling study

BACKGROUND One of the most important consequences of climate change could be its effects on agriculture. Although much research has focused on questions of food security, less has been devoted to assessing the wider health impacts of future changes in agricultural production. In this modelling study, we estimate excess mortality attributable to agriculturally mediated changes in dietary and weight-related risk factors by cause of death for 155 world regions in the year 2050. METHODS For this modelling study, we linked a detailed agricultural modelling framework, the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT), to a comparative risk assessment of changes in fruit and vegetable consumption, red meat consumption, and bodyweight for deaths from coronary heart disease, stroke, cancer, and an aggregate of other causes. We calculated the change in the number of deaths attributable to climate-related changes in weight and diets for the combination of four emissions pathways (a high emissions pathway, two medium emissions pathways, and a low emissions pathway) and three socioeconomic pathways (sustainable development, middle of the road, and more fragmented development), which each included six scenarios with variable climatic inputs. FINDINGS The model projects that by 2050, climate change will lead to per-person reductions of 3·2% (SD 0·4%) in global food availability, 4·0% (0·7%) in fruit and vegetable consumption, and 0·7% (0·1%) in red meat consumption. These changes will be associated with 529,000 climate-related deaths worldwide (95% CI 314,000-736,000), representing a 28% (95% CI 26-33) reduction in the number of deaths that would be avoided because of changes in dietary and weight-related risk factors between 2010 and 2050. Twice as many climate-related deaths were associated with reductions in fruit and vegetable consumption than with climate-related increases in the prevalence of underweight, and most climate-related deaths were projected to occur in south and east Asia. Adoption of climate-stabilisation pathways would reduce the number of climate-related deaths by 29-71%, depending on their stringency. INTERPRETATION The health effects of climate change from changes in dietary and weight-related risk factors could be substantial, and exceed other climate-related health impacts that have been estimated. Climate change mitigation could prevent many climate-related deaths. Strengthening of public health programmes aimed at preventing and treating diet and weight-related risk factors could be a suitable climate change adaptation strategy. FUNDING Oxford Martin Programme on the Future of Food.

Assessing the impact on chronic disease of incorporating the societal cost of greenhouse gases into the price of food: an econometric and comparative risk assessment modelling study

Objectives To model the impact on chronic disease of a tax on UK food and drink that internalises the wider costs to society of greenhouse gas (GHG) emissions and to estimate the potential revenue. Design An econometric and comparative risk assessment modelling study. Setting The UK. Participants The UK adult population. Interventions Two tax scenarios are modelled: (A) a tax of £2.72/tonne carbon dioxide equivalents (tCO2e)/100 g product applied to all food and drink groups with above average GHG emissions. (B) As with scenario (A) but food groups with emissions below average are subsidised to create a tax neutral scenario. Outcome measures Primary outcomes are change in UK population mortality from chronic diseases following the implementation of each taxation strategy, the change in the UK GHG emissions and the predicted revenue. Secondary outcomes are the changes to the micronutrient composition of the UK diet. Results Scenario (A) results in 7770 (95% credible intervals 7150 to 8390) deaths averted and a reduction in GHG emissions of 18 683 (14 665to 22 889) ktCO2e/year. Estimated annual revenue is £2.02 (£1.98 to £2.06) billion. Scenario (B) results in 2685 (1966 to 3402) extra deaths and a reduction in GHG emissions of 15 228 (11 245to 19 492) ktCO2e/year. Conclusions Incorporating the societal cost of GHG into the price of foods could save 7770 lives in the UK each year, reduce food-related GHG emissions and generate substantial tax revenue. The revenue neutral scenario (B) demonstrates that sustainability and health goals are not always aligned. Future work should focus on investigating the health impact by population subgroup and on designing fiscal strategies to promote both sustainable and healthy diets.

Plating up solutions

Can eating patterns be both healthier and more sustainable? The food system—that is, all the processes involved in feeding the global population—is responsible for ∼25% of global greenhouse gas (GHG) emissions. It also drives deforestation and biodiversity loss, land degradation, water overuse, and pollution, and creates and perpetuates inequalities within and across societies. And it does not even feed us effectively: While obesity and diet-related noncommunicable diseases escalate, hunger and micronutrient deficiencies persist. As the global population grows, becomes wealthier, and demands more resource-intensive foods, these problems are likely to worsen. A systemic approach that jointly addresses problems related to production, consumption, and inequity is needed.

Meat consumption, health, and the environment

The future of meat Meat consumption is rising annually as human populations grow and affluence increases. Godfray et al. review this trend, which has major negative consequences for land and water use and environmental change. Although meat is a concentrated source of nutrients for low-income families, it also enhances the risks of chronic ill health, such as from colorectal cancer and cardiovascular disease. Changing meat consumption habits is a challenge that requires identifying the complex social factors associated with meat eating and developing policies for effective interventions. Science, this issue p. eaam5324 BACKGROUND The global average per capita consumption of meat and the total amount of meat consumed are rising (see the figure), driven by increasing average individual incomes and by population growth. Growth rates vary across different regions, with consumption in high-income countries static or declining and in middle-income countries moderately to strongly increasing, whereas in low-income countries, meat consumption is on average low and stable. There has been a particularly marked increase in the global consumption of chicken and pork. The consumption of different types of meat and meat products has substantial effects on people’s health, and livestock production can have major negative effects on the environment. ADVANCES Meat is a good source of energy and some essential nutrients—including protein and micronutrients such as iron, zinc, and vitamin B12—although it is possible to obtain a sufficient intake of these nutrients without eating meat if a wide variety of other foods is available and consumed. In high-income Western countries, large prospective studies and meta-analyses generally show that total mortality rates are modestly higher in participants who have high intakes of red and processed meat. The strongest evidence of a specific adverse effect is the increased risk of colorectal cancer with high intakes of processed meat. Meat produces more emissions per unit of energy compared with that of plant-based foods because energy is lost at each trophic level. Within types of meat, ruminant production usually leads to more emissions than that of nonruminant mammals, and poultry production usually leads to less emissions than that of mammals. Meat production is the single most important source of methane, which has a relatively high warming potential but a low half-life in the environment compared with that of CO2. Careful management of grassland systems can contribute to carbon storage, but the net benefits are likely to be relatively modest. Agriculture uses more freshwater than any other human activity, with nearly a third required for livestock, so meat production in water-stressed areas is a major competitor with other uses of water, including that required to maintain natural ecosystems. Meat production can be an important source of nitrogen, phosphorus, and other pollutants and affects biodiversity—in particular, through land conversion to pasture and arable feed crops. OUTLOOK Governments act to shape food systems for economic purposes and to protect health from contaminated food. But there is less agreement over the degree to which the state should use health, environmental, or animal welfare considerations to control the supply of meat through interventions that affect the production, sale, processing, and distribution of meat and meat products or the price to the consumer. If we are to shape consumer demand, more evidence is needed about the effectiveness of different interventions to influence food selection. This may include interventions that affect either the conscious, reflective decision-making systems or nonconscious, automatic processes. Potential interventions within the rational choice paradigm include labeling schemes (based on health or environmental criteria) and certification programs (based on welfare or environmental considerations) or fiscal interventions (such as so-called fat taxes). Alternatively, the largely automatic responses to environmental cues that affect purchase and consumption behaviors can be manipulated by changes to the food environment, in retail and food consumption settings. History suggests that change in dietary behaviors in response to interventions is slow. But social norms can and do change, and this process can be aided by the coordinated efforts of civil society, health organizations, and government. However, successful interventions to improve health and environmental objectives are likely to require a good understanding of the impact of meat consumption on these outcomes, as well as a license from society for governments and other bodies to implement a suite of interventions to stimulate change. Total consumption of meat (in million metric tons) in different regions and (inset) globally. [Data are from www.fao.org/faostat/en/?#data.] Both the global average per capita consumption of meat and the total amount of meat consumed are rising, driven by increasing average individual incomes and by population growth. The consumption of different types of meat and meat products has substantial effects on people’s health, and livestock production can have major negative effects on the environment. Here, we explore the evidence base for these assertions and the options policy-makers have should they wish to intervene to affect population meat consumption. We highlight where more research is required and the great importance of integrating insights from the natural and social sciences.

A whole-economy model of the health co-benefits of strategies to reduce greenhouse gas emissions in the UK

Abstract Background The UK Government has set specific targets for greenhouse gas emissions to lower the risk of dangerous climate change. Previous research has shown that important health co-benefits could result from strategies targeting the domains of transport, built environment, and agriculture. This study assesses the full general equilibrium economy-wide macroeconomic effects of health co-benefits from three similar UK strategies to meet locally specific 2030 greenhouse gas emission targets. Methods Economy-wide effects of health co-benefits were modelled with a dynamic extension of the widely used International Food Policy Research Institute standard computable general equilibrium model for 2011–30. Four forms of economic agents are modelled: firms (who combine resource inputs to maximise profits), consumers (who consume and save to maximise their welfare), government, and foreign agents. The method consists of simulation of three greenhouse gas policy scenarios and a counterfactual do-nothing scenario. Basic health co-benefits (years lived with disability [YLD] and years of life lost [YLL]) were measured for a range of illnesses, on the basis of the comparative risk assessment approach. Combined with incidence numbers and prevalence trends, these basic YLD (morbidity) and YLL (mortality) co-benefits were used to calculate dynamic sequences of demographic and labour market effects on population and productive labour supply, and public budget implications for averted health-care costs and increased social security transfers (including benefit payments for working-age individuals and pension payments for old-age individuals). These economic shocks were subsequently imposed on the computable general equilibrium model and used to measure the combined macroeconomic effect of health co-benefits. The method for measuring averted health-care costs was published in The Lancet in 2012. Three scenarios were modelled: active travel (transport sector; health co-benefits of an assumed transformation of urban transport behaviour to reduce motorised transportation and increase walking [2·5-times] and cycling [8·0-times] in urban England and Wales); healthy diet (food and agriculture sector; health co-benefits of an assumed UK-wide 30% reduction in consumption of dietary saturated fat); and household energy (household energy sector; health co-benefits of an assumed UK-wide improvement in home insulation and ventilation, including reduced household energy use, improved indoor temperature, and associated changes in indoor pollutants). Findings For all scenarios, the macroeconomic effects of health co-benefits are positive. Overall, substantial savings on health-care costs represent the main contributing factor. Increased labour supplies also contribute positively, whereas increased social security transfers (due to larger working-age and old-age population segments) detract. The largest potential cumulative gross domestic product gains from health co-benefits are associated with the active travel scenario (around £19 billion), in which increased physical activity averts large-scale and long-term chronic disease burdens and health-system costs. The healthy diet scenario also leads to important potential gains (around £5 billion), whereas the full potential health co-benefits from the household energy scenario will not be realised until beyond 2030. Three economic sensitivity analyses were undertaken to test the sensitivity of results to variations in assumptions concerning: the substitutability of labour for other factors of production; the effectiveness of the interventions; and changes in the discount rate (the present value of the economic effects). Overall, the core results can be considered relatively robust to changes in these three factors. Interpretation Strategies to reduce greenhouse gas emissions and improve health are likely to result in substantial and increasing positive contributions to the economy. This effect might offset some economic costs and thereby allow such strategies to be seen more favourably, especially in times of economic austerity. Funding Department of Health Policy Research Programme.

Review on drivers, trends and emerging issues of the food wastage in China

China has successfully achieved food self- sufficiency over the past 50 years, however, with large inputs and losses. To meet the challenge of feeding a growing population with limited resources, many studies have explored options for improving productivity and efficiency of the food production. However, there have been few studies into the potential of reducing food loss along the whole food production-consumption chain. Here we review the literature on food waste in China. We briefly analyze (1) the drivers that influence levels of food waste in the food chain, (2) examine trends in the volumes and types of food wasted at different stages in the food chain, (3) assess the environmental and resource consequences of food waste in the food chain, and (4) evaluate the policy and stakeholder responses to the emerging challenges. It is concluded that reducing food loss and meeting food security in China requires a coherent institutional structure that promotes the synergistic outcomes of research, policy and education. Suggested key actions include (1) improving machinery and facility for sowing, harvest- ing, transportation and storage, which can reduce food loss by up to 50%, and (2) improving food waste recycling management, based on coupled food production and consumption systems.