Global food system emissions could preclude achieving the 1.5° and 2°C climate change targets

Land-use emissions embodied in international trade

International trade separates consumption of goods from related environmental impacts, including greenhouse gas emissions from agriculture and land-use change (together referred to as "land-use emissions"). Through use of new emissions estimates and a multiregional input-output model, we evaluated land-use emissions embodied in global trade from 2004 to 2017. Annually, 27% of land-use emissions and 22% of agricultural land are related to agricultural products ultimately consumed in a different region from where they were produced. Roughly three-quarters of embodied emissions are from land-use change, with the largest transfers from lower-income countries such as Brazil, Indonesia, and Argentina to more industrialized regions such as Europe, the United States, and China. Mitigation of global land-use emissions and sustainable development may thus depend on improving the transparency of supply chains.

Perspective: Soybeans Can Help Address the Caloric and Protein Needs of a Growing Global Population

Feeding a growing global population with projected rising socioeconomic status will require additional sources of calories and especially protein. These sources need to align with the Sustainable Development Goals established by the Food and Agriculture Organization of the United Nations. The soybean is uniquely positioned to meet this challenge based on the following criteria: (1) Global soybean production exceeds by ~4 times the production of all pulses combined (2) Soybeans are higher in protein than other legumes and soy protein quality is similar to animal protein quality (3) Soybeans are an excellent source of healthy fat, including both essential fatty acids (4) Soybeans, like other legumes, symbiotically fix atmospheric nitrogen thereby reducing the need for fertilizer inputs (5) Greenhouse gas emissions per unit protein are lower than for nearly all other foods (6) Soybeans, like other legumes, are also recognized as an affordable food that can be incorporated into diverse diets regardless of economic standing and (7) The range of foods produced from soybeans constitutes an important position in historic and contemporary cuisines, cultures and emerging consumer trends for plant-based protein. Although most soybeans are currently used for animal feed, soybean use is dictated by consumer demand. Therefore, soybeans are well positioned to meet future global needs for energy and protein. Armed with this knowledge, health professionals can feel justified in encouraging greater consumption of soyfoods for both personal and planetary reasons.

Activity-Based Approach for Selective Molecular CO2 Sensing

Carbon dioxide (CO₂) impacts every aspect of life, and numerous sensing technologies have been established to detect and monitor this ubiquitous molecule. However, its selective sensing at the molecular level remains an unmet challenge, despite the tremendous potential of such an approach for understanding this molecule's role in complex environments. In this work, we introduce a unique class of selective fluorescent carbon dioxide molecular sensors (CarboSen) that addresses these existing challenges through an activity-based approach. Besides the design, synthesis, and evaluation of these small molecules as CO₂ sensors, we demonstrate their utility by tailoring their reactivity and optical properties, allowing their use in a broad spectrum of multidisciplinary applications, including atmospheric sensing, chemical reaction monitoring, enzymology, and live-cell imaging. Collectively, these results showcase the potential of CarboSen sensors as broadly applicable tools to monitor and visualize carbon dioxide across multiple disciplines.

Integrating degrowth and efficiency perspectives enables an emission-neutral food system by 2100

Degrowth proponents advocate reducing ecologically destructive forms of production and resource throughput in wealthy economies to achieve environmental goals, while transforming production to focus on human well-being. Here we present a quantitative model to test degrowth principles in the food and land system. Our results confirm that reducing and redistributing income alone, within current development paradigms, leads to limited greenhouse gas (GHG) emission mitigation from agriculture and land-use change, as the nutrition transition towards unsustainable diets already occurs at relatively low income levels. Instead, we show that a structural, qualitative food system transformation can achieve a steady-state food system economy that is net GHG-neutral by 2100 while improving nutritional outcomes. This sustainable transformation reduces material throughput via a convergence towards a needs-based food system, is enabled by a more equitable income distribution and includes efficient resource allocation through the pricing of GHG emissions as a complementary strategy. It thereby integrates degrowth and efficiency perspectives.

Averting wildlife-borne infectious disease epidemics requires a focus on socio-ecological drivers and a redesign of the global food system

A debate has emerged over the potential socio-ecological drivers of wildlife-origin zoonotic disease outbreaks and emerging infectious disease (EID) events. This Review explores the extent to which the incidence of wildlife-origin infectious disease outbreaks, which are likely to include devastating pandemics like HIV/AIDS and COVID-19, may be linked to excessive and increasing rates of tropical deforestation for agricultural food production and wild meat hunting and trade, which are further related to contemporary ecological crises such as global warming and mass species extinction. Here we explore a set of precautionary responses to wildlife-origin zoonosis threat, including: (a) limiting human encroachment into tropical wildlands by promoting a global transition to diets low in livestock source foods; (b) containing tropical wild meat hunting and trade by curbing urban wild meat demand, while securing access for indigenous people and local communities in remote subsistence areas; and (c) improving biosecurity and other strategies to break zoonosis transmission pathways at the wildlife-human interface and along animal source food supply chains.

Meat, money and messaging: How the environmental and health harms of red and processed meat consumption are framed by the meat industry

Calls to cut consumption of red and processed meat, in order to protect both human and planetary health, are drawing increased attention from policy actors. This poses a potential threat to meat industry profits. It is well evidenced that producers of other harmful commodities (such as fossil fuels or tobacco) respond with a range of tactics to impede policy action when similarly threatened, including framing the issues at stake in a light more favourable to industry interests. In order to investigate how the meat industry in the UK frames discussions about the environmental and health impacts of red and processed meat consumption, thematic content analysis was performed on documents sourced from the websites of 6 organisations representing the UK meat industry. Across the dataset, four main framings were identified; 'still open for debate', 'most people have no need to worry', 'keep eating meat to be healthy' and 'no need to cut down to be green'. These frames work in conjunction to minimise the perception of harm, whilst also encouraging continued consumption. Messages were constructed using 'classic' framing devices employed by other producers of harmful commodities. These findings are of importance as they provide insight into how debates about food policy may be influenced by meat industry framing of the issues at hand.

Consumer Acceptance of Plant-Based Meat Substitutes: A Narrative Review

The great environmental impact of increasing animal product consumption requires the willingness to reduce or to substitute meat consumption. A possible substitute product, plant-based meat substitute, is made from plants and offers a sensory experience similar to conventional meat. In this narrative review, we focus on the consumer acceptance of plant-based meat alternatives. We searched for peer-reviewed studies in SCOPUS and Web of Science (WoS) up to December 2021. Of all 111 records identified, 28 were eligible, and, thus, included in this narrative review. The results imply that established consumer behavior has complex socio-economic implications for the adoption of plant-based meat substitutes. Plant-based meat was consistently rated more favorably than other meat substitute products, but sensory and nutritional implications still exist. Environmental and health-related factors may contribute to the market spread of plant-based meat substitutes, but these factors alone are not sufficient. Furthermore, so far there is no information available about how the hypothetical measurements used in the studies (such as willingness to pay) will translate to real life consumer behavior. Despite these barriers, there is certainly a great market potential for plant-based meat alternatives, which is expected to be more pronounced in the future, with increasing environmental and health awareness.

Factors Affecting Residential End-Use Energy: Multiple Regression Analysis Based on Buildings, Households, Lifestyles, and Equipment

Building characteristics, household compositions, lifestyles, and home equipment are recognized as the main factors influencing residential energy consumption, which has been a subject of extensive exploration for many years now. However, the quantitative correlation models between the above factors and residential end-use energy have not been fully studied. This paper aims to explore the determinants of residential end-use energy consumption by a comprehensive analysis based on the factors of building characteristics, household compositions, lifestyles, and home equipment. For this purpose, we investigated and collected the building information of 66 households and obtained the data through an installed measurement system of the annual residential end-use energy from July 2019 to June 2020. Subsequently, six multiple regression models were used to quantitatively analyze the valid determinants of each end-use energy. The main results were as follows: for cooling energy consumption, the greatest effective variable was FM_no (22–59, number of family members aged 22 to 59); the most influential variable was found to be FM_no (number of family members) for DHW and appliances energy consumption; for lighting and cooking energy consumption, the most effective variables were AREA (floor area) and Cooking (average daily cooking hours), respectively. Moreover, the order of influence of building characteristics, household compositions, lifestyles, and home equipment over each end-use energy consumption is as follows: households > equipment > lifestyles for cooling and DHW, households > buildings > equipment for lighting, equipment > lifestyles for appliances and cooking.

Nitrogen isotopic discrimination as a biomarker of between-cow variation in the efficiency of nitrogen utilization for milk production: A meta-analysis

Estimating the efficiency of N utilization for milk production (MNE) of individual cows at a large scale is difficult, particularly because of the cost of measuring feed intake. Nitrogen isotopic discrimination (Δ¹⁵N) between the animal (milk, plasma, or tissues) and its diet has been proposed as a biomarker of the efficiency of N utilization in a range of production systems and ruminant species. The aim of this study was to assess the ability of Δ¹⁵N to predict the between-animal variability in MNE in dairy cows using an extensive database. For this, 20 independent experiments conducted as either changeover (n = 14) or continuous (n = 6) trials were available and comprised an initial data set of 1,300 observations. Between-animal variability was defined as the variation observed among cows sharing the same contemporary group (CG; individuals from the same experimental site, sampling period, and dietary treatment). Milk N efficiency was calculated as the ratio between mean milk N (grams of N in milk per day) and mean N intake (grams of N intake per day) obtained from each sampling period, which lasted 9.0 ± 9.9 d (mean ± SD). Samples of milk (n = 604) or plasma (n = 696) and feeds (74 dietary treatments) were analyzed for natural ¹⁵N abundance (δ¹⁵N), and then the N isotopic discrimination between the animal and the dietary treatment was calculated (Δ¹⁵n = δ¹⁵N_animal - δ¹⁵N_diet). Data were analyzed through mixed-effect regression models considering the experiment, sampling period, and dietary treatment as random effects. In addition, repeatability estimates were calculated for each experiment to test the hypothesis of improved predictions when MNE and Δ¹⁵N measurements errors were lower. The considerable protein mobilization in early lactation artificially increased both MNE and Δ¹⁵N, leading to a positive rather than negative relationship, and this limited the implementation of this biomarker in early lactating cows. When the experimental errors of Δ¹⁵N and MNE decreased in a particular experiment (i.e., higher repeatability values), we observed a greater ability of Δ¹⁵N to predict MNE at the individual level. The predominant negative and significant correlation between Δ¹⁵N and MNE in mid- and late lactation demonstrated that on average Δ¹⁵N reflects MNE variations both across dietary treatments and between animals. The root mean squared prediction error as a percentage of average observed value was 6.8%, indicating that the model only allowed differentiation between 2 cows in terms of MNE within a CG if they differed by at least 0.112 g/g of MNE (95% confidence level), and this could represent a limitation in predicting MNE at the individual level. However, the one-way ANOVA performed to test the ability of Δ¹⁵N to differentiate within-CG the top 25% from the lowest 25% individuals in terms of MNE was significant, indicating that it is possible to distinguish extreme animals in terms of MNE from their N isotopic signature, which could be useful to group animals for precision feeding.

European Forest Governance: Status Quo and Optimising Options with Regard to the Paris Climate Target

This article assesses and develops policy instruments for forest governance in the EU. Methodologically, it examines opportunities and limits for negative emissions by means of a literature review. On this basis, it conducts a qualitative governance analysis of the most important instruments of EU forest policy and presents optimizing policy options, measured against the binding climate and biodiversity targets under international law. Our analysis shows that the potential benefits of afforestation and reforestation for climate mitigation are overestimated, and are often presented as the new saviours to assist in reaching climate neutrality, inter alia, since only biodiverse and thus resilient forests can function as a carbon sink in the long term. Furthermore, we demonstrate that the existing EU law fails to comply with climate and biodiversity targets. Quantity governance systems for livestock farming, fossil fuels and similar drivers of deforestation represent a more promising approach to forest governance than the dominant regulatory and subsidy-based governance. They are most effective when not directly addressing forests due to their heterogeneity but central damaging factors such as fossil fuels and livestock farming. Selected aspects of regulatory and subsidy law can supplement these quantity governance systems when focusing on certain easily attainable and thus controllable subjects. These include, e.g., the regulatory protection of old-growth forests with almost no exceptions and a complete conversion of all agricultural and forest subsidies to “public money for public services” to promote nature conservation and afforestation.

Deceleration of Cropland-N2O Emissions in China and Future Mitigation Potentials

Agricultural soils are the largest anthropogenic emission source of nitrous oxide (N2O). National agricultural policies have been implemented to increase crop yield and reduce nitrogen (N) losses to the environment. However, it is difficult to effectively quantify crop-specific and regional N2O mitigation priorities driven by policies, due to lack of long-term, high-resolution crop-specific activity data, and oversimplified models. Here, we quantify the spatiotemporal changes and key drivers of crop-specific cropland-N2O emissions from China between 1980 and 2017, and future N2O mitigation potentials, using a linear mixed-effect model and survey-based data set of agricultural management measures. Cropland-N2O emissions from China tripled from 102.5 to 315.0 Gg N yr-1 between 1980 and 2017, and decelerated since 1998 mainly driven by country-wide deceleration and decrease in N rate and the changes in sowing structure. About 63% of N2O emissions could be reduced in 2050, primarily in the North China Plain and Northeast China Plain; 83% of which is from the production of maize (33%), vegetables (27%), and fruits (23%). The deceleration of N2O emissions highlights that policy interventions and agronomy practices (i.e., optimizing N rate and sowing structure) are potential pathways for further ambitious N2O mitigation in China and other developing countries.

How do we best synergize climate mitigation actions to co-benefit biodiversity?

A multitude of actions to protect, sustainably manage and restore natural and modified ecosystems can have co-benefits for both climate mitigation and biodiversity conservation. Reducing greenhouse emissions to limit warming to less than 1.5 or 2°C above preindustrial levels, as outlined in the Paris Agreement, can yield strong co-benefits for land, freshwater and marine biodiversity and reduce amplifying climate feedbacks from ecosystem changes. Not all climate mitigation strategies are equally effective at producing biodiversity co-benefits, some in fact are counterproductive. Moreover, social implications are often overlooked within the climate-biodiversity nexus. Protecting biodiverse and carbon-rich natural environments, ecological restoration of potentially biodiverse and carbon-rich habitats, the deliberate creation of novel habitats, taking into consideration a locally adapted and meaningful (i.e. full consequences considered) mix of these measures, can result in the most robust win-win solutions. These can be further enhanced by avoidance of narrow goals, taking long-term views and minimizing further losses of intact ecosystems. In this review paper, we first discuss various climate mitigation actions that evidence demonstrates can negatively impact biodiversity, resulting in unseen and unintended negative consequences. We then examine climate mitigation actions that co-deliver biodiversity and societal benefits. We give examples of these win-win solutions, categorized as 'protect, restore, manage and create', in different regions of the world that could be expanded, upscaled and used for further innovation.

Extension services can promote pasture restoration: Evidence from Brazil's low carbon agriculture plan

Innovation and improved practices in the livestock sector represent key opportunities tomeet global climate goals. This paper provides evidence that extension services can pro-mote pasture restoration in cattle ranching in Brazil. We use a randomized controlledtrial implemented in the context of the ABC Cerrado (a large-scale program launched in2014 aimed at fostering technology adoption through a combination of training andtechnical assistance) to examine the effects of different types of extension on agriculturalpractices, input use, and productivity. Providing technical assistance to previously trainedproducers promoted pasture restoration, induced farmers to use inputs more intensively,helped them to improve their management and soil conservation practices, and substan-tially increased revenues. A cost–benefit calculation indicates that US$1 invested in theABC Cerrado program increased profits by US$1.08 to $1.45. Incorporating carbonsavings amplifies this return considerably.

Predicting field N2O emissions from crop residues based on their biochemical composition: A meta-analytical approach

Crop residue incorporation is a common practice to increase or restore organic matter stocks in agricultural soils. However, this practice often increases emissions of the powerful greenhouse gas nitrous oxide (N₂O). Previous meta-analyses have linked various biochemical properties of crop residues to N₂O emissions, but the relationships between these properties have been overlooked, hampering our ability to predict N₂O emissions from specific residues. Here we combine comprehensive databases for N₂O emissions from crop residues and crop residue biochemical characteristics with a random-meta-forest approach, to develop a predictive framework of crop residue effects on N₂O emissions. On average, crop residue incorporation increased soil N₂O emissions by 43% compared to residue removal, however crop residues led to both increases and reductions in N₂O emissions. Crop residue effects on N₂O emissions were best predicted by easily degradable fractions (i.e. water soluble carbon, soluble Van Soest fraction (NDS)), structural fractions and N returned with crop residues. The relationship between these biochemical properties and N₂O emissions differed widely in terms of form and direction. However, due to the strong correlations among these properties, we were able to develop a simplified classification for crop residues based on the stage of physiological maturity of the plant at which the residue was generated. This maturity criteria provided the most robust and yet simple approach to categorize crop residues according to their potential to regulate N₂O emissions. Immature residues (high water soluble carbon, soluble NDS and total N concentration, low relative cellulose, hemicellulose, lignin fractions, and low C:N ratio) strongly stimulated N₂O emissions, whereas mature residues with opposite characteristics had marginal effects on N₂O. The most important crop types belonging to the immature residue group - cover crops, grasslands and vegetables - are important for the delivery of multiple ecosystem services. Thus, these residues should be managed properly to avoid their potentially high N₂O emissions.

Central Persons in Sustainable (Food) Consumption

What people eat has become a highly political issue, closely intertwined with public health, environmental concerns, and climate change. Individuals' consumption decisions tend to be greatly influenced by the people that surround them, and this seems to be especially true when it comes to food. In recent years, alongside close contacts, such as family and friends, a myriad of social influencers have appeared on the screens, sharing opinions on what (not) to eat. Presenting results from a youth survey conducted in Sweden in 2019 (N = 443), this paper shows that social media have become the primary source of information about food and eating for youths, followed by schools and families. However, primary sources of influence continue to be parents and the family at large. Furthermore, the study shows that it is possible to identify 'central persons', i.e., relatively clear-cut groups of people whose food choices-measured as tendency to eat climate friendly-is mirrored by the youths, both in their everyday food preferences and in their broader political awareness as expressed through political consumerism. A conclusion from this is that certain people can be particularly successful at inspiring larger numbers of other people to engage with healthier and environmentally friendlier (food) consumption in a society.

Designing Environmental Messages to Discourage Red Meat Consumption: An Online Experiment

Reducing red meat consumption in high-consuming countries is critical for mitigating climate change and preventing chronic disease. This study tested the effectiveness of messages conveying the worsening or reduction of environmental harms at discouraging red meat consumption. 1078 U.S. adults viewed seven messages in an online survey highlighting the reduction or worsening of environmental harms associated with eating red meat (between-subjects factor) and rated the messages on how much they discouraged them from wanting to buy beef. Each message highlighted a different environmental harm: deforestation, climate change, water shortages, biodiversity loss, carbon footprint, greenhouse gas emissions, or environment (within-subjects factor). No statistically significant difference was found between the reduction and worsening of environmental harms conditions for most topics, though the worsening of harms frame slightly outperformed the reduction of harms frame for the 'environment' topic. 'Environment' was also the message topic that elicited the strongest response from participants overall. Latino participants, those with more than a high school degree, and those who consume beef once a week or less rated messages as more effective than non-Latino participants, those who completed high school or less, and those who consumed beef more than once a week. Future research should explore the effect of messages on behavioral outcomes.

Physicochemical and Functional Modifications of Hemp Protein Concentrate by the Application of Ultrasonication and pH Shifting Treatments

According to the Food and Agriculture Organization (FAO), protein demand is expected to increase globally by around 40% by 2030 as a response to the world's population growth. Due to their clean label, vegan or vegetarian based applications, nutritional value, and cost-efficient properties, plant-based proteins have been widely studied. However, most of the alternatives currently found in the market have some challenges because of their poor solubility, emulsifying, gelling, and foaming attributes. Hemp seed protein has gained increasing attention due to its unique amino acids and fatty acids profiles. In this study, commercial HPC mixtures were adjusted to pH 2, 4, 6, 8, 10, and 12 followed by ultrasonication (US) for 5 min (5 s on: 5 s off) and incubated for an hour before neutralizing to pH 7. Following the treatments, the samples were analyzed for their hydrodynamic diameter, conductivity, zeta potential, polydispersity index, surface hydrophobicity, solubility, electrophoresis (SDS-PAGE), free sulfhydryl group, and optical characteristics. The samples treated with ultrasound at pH 8 and 10 significantly (p < 0.05) enhanced the solubility of the hemp seed protein by 12.12% and 19.05%, respectively. Similarly, the samples treated with ultrasonication and pH shifting at pH 6, 8, and 10 also significantly increased the amount of free sulfhydryl content (p < 0.05) to 41.6, 58.72, and 46.54 mmol/g from 32.8 mmol/g, respectively. This study shows that the application of ultrasonication and pH shifting is a promising alternative method to modify the functional properties of HPC and widen their applications in the food, cosmetics, and pharmaceutical industries.

Production of Sustainable Proteins Through the Conversion of Insects to Proteins Using Beauveria bassiana Cultures

Various strategies are being suggested to solve the challenges in the food system, such as changing the source of nutrients, including the use of non-traditional food sources such as insects. Although insects are promoted as a cheap and sustainable source of protein, consumers are reluctant to eat them. The mycoproteins produced by fungi, on the other hand, are very well received and appreciated by consumers. Thus, in this work we have studied the use of the entomopathogenic fungi Beauveria bassiana (Ascomycota: Hypocreales) for the production of protein using insects as feed. B. bassiana was cultivated in culture medium containing entire insects from the species Eurysacca and Hypothenemus or single carbon sources such as glucose or laminarin from Laminaria digitata. The results showed that B. bassiana can produce up to 16-fold more biomass and 8-fold more protein when grown in insect-based medium than when grown in glucose. The results also indicated that the production of proteins continuously increased when B. bassiana was grown in medium containing insects, reaching its maximum at 9 days (up to 3 mg/mL). On the other hand, when cultivated in glucose-supplemented medium, the production of proteins was constantly low (~0.5 mg/mL). In conclusion, B. bassiana was a large biomass producer and exuded a large amount of protein when grown in medium containing insect powder, making it an ideal intermediate link between insects and protein. Furthermore, the proteins produced by fungi such as B. bassiana can be used in the food, health, and cosmetic industries.

Sustainable food systems and nutrition in the 21st century: a report from the 22nd annual Harvard Nutrition Obesity Symposium

Food systems are at the center of a brewing storm consisting of a rapidly changing climate, rising hunger and malnutrition, and significant social inequities. At the same time, there are vast opportunities to ensure that food systems produce healthy and safe food in equitable ways that promote environmental sustainability, especially if the world can come together at the UN Food Systems Summit in late 2021 and make strong and binding commitments toward food system transformation. The NIH-funded Nutrition Obesity Research Center at Harvard and the Harvard Medical School Division of Nutrition held their 22nd annual Harvard Nutrition Obesity Symposium entitled "Global Food Systems and Sustainable Nutrition in the 21st Century" in June 2021. This article presents a synthesis of this symposium and highlights the importance of food systems to addressing the burden of malnutrition and noncommunicable diseases, climate change, and the related economic and social inequities. Transformation of food systems is possible, and the nutrition and health communities have a significant role to play in this transformative process.

Dietary change in high-income nations alone can lead to substantial double climate dividend

A dietary shift from animal-based foods to plant-based foods in high-income nations could reduce greenhouse gas emissions from direct agricultural production and increase carbon sequestration if resulting spared land was restored to its antecedent natural vegetation. We estimate this double effect by simulating the adoption of the EAT-Lancet planetary health diet by 54 high-income nations representing 68% of global gross domestic product and 17% of population. Our results show that such dietary change could reduce annual agricultural production emissions of high-income nations' diets by 61% while sequestering as much as 98.3 (55.6-143.7) GtCO₂ equivalent, equal to approximately 14 years of current global agricultural emissions until natural vegetation matures. This amount could potentially fulfil high-income nations' future sum of carbon dioxide removal (CDR) obligations under the principle of equal per capita CDR responsibilities. Linking land, food, climate and public health policy will be vital to harnessing the opportunities of a double climate dividend.

Spatial differentiation identification of influencing factors of agricultural carbon productivity at city level in Taihu lake basin, China

Improving carbon productivity is the main way to deal with climate change under China's targets for carbon emissions to peak by 2030 and carbon neutrality by 2060. This study identified the spatial differentiation of influencing factors of agricultural carbon productivity at the city level in Taihu lake basin, and formed differentiated agricultural management strategies. The results show that: (1) Spatial differentiation of agricultural carbon productivity is obvious at city level. It can be divided into three echelons: the first echelon is Shanghai and Hangzhou (agricultural carbon productivity≥10,000 Yuan/t in 2019 with a growth rate ≥ 600% compared with 1992), the second echelon is Suzhou, Wuxi and Changzhou (9000 Yuan/t ≤ agricultural carbon productivity<10,000 Yuan/t in 2019 with 381% ≤ growth rate < 600% compared with 1992), and the third echelon is Zhenjiang, Huzhou and Jiaxing (agricultural carbon productivity<9000 Yuan/t in 2019 or a growth rate < 381% compared with 1992). (2) There is a synergetic evolution law between agricultural carbon productivity and agricultural economy, that is, agricultural economic development level is the first factor affecting agricultural carbon productivity, whether in the whole basin or in the city level. (3) There are significant differences in the influencing factors of agricultural carbon productivity at the city level. Finally, according to the spatial differentiation characteristics of influencing factors of agricultural carbon productivity at the city level in Taihu lake basin, we put forward different emphases of agricultural development in different cities.

Short- and long-term warming effects of methane may affect the cost-effectiveness of mitigation policies and benefits of low-meat diets

Methane’s short atmospheric life has important implications for the design of global climate change mitigation policies in agriculture. Three different agricultural economic models are used to explore how short- and long-term warming effects of methane can affect the cost-effectiveness of mitigation policies and dietary transitions. Results show that the choice of a particular metric for methane’s warming potential is key to determine optimal mitigation options, with metrics based on shorter-term impacts leading to greater overall emission reduction. Also, the promotion of low-meat diets is more effective at reducing greenhouse gas emissions compared to carbon pricing when mitigation policies are based on metrics that reflect methane’s long-term behaviour. A combination of stringent mitigation measures and dietary changes could achieve substantial emission reduction levels, helping reverse the contribution of agriculture to global warming.

Examining the Environmental Impacts of the Dairy and Baby Food Industries: Are First-Food Systems a Crucial Missing Part of the Healthy and Sustainable Food Systems Agenda Now Underway?

Food systems are increasingly being understood as driving various health and ecological crises and their transformation is recognised as a key opportunity for planetary health. First-food systems represent an underexplored aspect of this transformation. Despite breastfeeding representing the optimal source of infant nutrition, use of commercial milk formula (CMF) is high and growing rapidly. In this review, we examine the impact of CMF use on planetary health, considering in particular its effects on climate change, water use and pollution and the consequences of these effects for human health. Milk is the main ingredient in the production of CMF, making the role of the dairy sector a key area of attention. We find that CMF use has twice the carbon footprint of breastfeeding, while 1 kg of CMF has a blue water footprint of 699 L; CMF has a significant and harmful environmental impact. Facilitation and protection of breastfeeding represents a key part of developing sustainable first-food systems and has huge potential benefits for maternal and child health.

Closing Research Investment Gaps for a Global Food Transformation

Recent calls for a global food transformation have centered on simultaneously improving human and environmental health, recognizing that food and nutrient diversity have declined over time while food systems have exacted a heavy climate and ecological toll. Grain legumes and coarse grain crops provide important human nutrition and environmental benefits, but the production and consumption of many of these crops remains relatively low compared to major commodities, such as maize, wheat, rice, and soy. Outstanding hurdles to scaling up these “minor commodity” crops include (among other things) their relatively lower yields, and lower farmer adoption, based partly on actual or perceived profitability and marketability. We hypothesize that these limitations are attributable in part to unequal funding for these crops' research and development (R&amp;D) both on a national and global scale. In the United States, we show that investment patterns for a snapshot of USDA-funded research grants from 2008 to 2019 consistently favor major commodity crops, which received 3 to 4.5 times more funding and 3 to 5 times as many grants than the minor commodity crop groups. This current USDA funding allocation poses a barrier to food system transformations. Achieving nutritious diets for planetary health requires more public agricultural investment toward minor commodity crops and increased collaboration between public health, nutrition, agriculture, and environmental sectors.

Safety evaluation of transgenic and genome-edited food animals

There is an urgent need to reform the regulation of transgenic and genome-edited food animals. Now is the time to simplify regulatory safety guidelines based on science before it is too late to have these animals in place to meet societal needs in coming decades.

Differences in Environmental Impact between Plant-Based Alternatives to Dairy and Dairy Products: A Systematic Literature Review

A large body of research suggests a more plant-based diet, including a switch to plant-based alternatives to dairy, is needed for lowering human-induced climate change as well as land and water use. With the help of a systematic literature review, we analyzed data from 21 peer-reviewed articles about the differences in emissions and resources used between various plant-based alternatives to dairy and dairy products. Emissions included were greenhouse gases, acidifying, eutrophicating, and ozone-depleting substances, and resource use included water, energy, and land. The results are presented as the quotients of the ratios of plant-based alternatives to dairy and dairy products. The comparison shows that the plant-based dairy alternatives have lower, or much lower, impacts in almost all cases, with two exceptions: water use for almond drinks (several studies) and emissions of ozone-depleting substances for margarine (one study). There is a lack of data concerning impacts other than greenhouse gas emissions for plant-based cheese alternatives; and in general, emissions of greenhouse gases are more highly covered than other impacts. In the quest for a swift transition to a low carbon economy, however, there is already enough evidence to proceed with a dietary change involving switching dairy products to plant-based alternatives.

How necessary and feasible are reductions of methane emissions from livestock to support stringent temperature goals?

Agriculture is the largest single source of global anthropogenic methane (CH4) emissions, with ruminants the dominant contributor. Livestock CH4 emissions are projected to grow another 30% by 2050 under current policies, yet few countries have set targets or are implementing policies to reduce emissions in absolute terms. The reason for this limited ambition may be linked not only to the underpinning role of livestock for nutrition and livelihoods in many countries but also diverging perspectives on the importance of mitigating these emissions, given the short atmospheric lifetime of CH4. Here, we show that in mitigation pathways that limit warming to 1.5°C, which include cost-effective reductions from all emission sources, the contribution of future livestock CH4 emissions to global warming in 2050 is about one-third of that from future net carbon dioxide emissions. Future livestock CH4 emissions, therefore, significantly constrain the remaining carbon budget and the ability to meet stringent temperature limits. We review options to address livestock CH4 emissions through more efficient production, technological advances and demand-side changes, and their interactions with land-based carbon sequestration. We conclude that bringing livestock into mainstream mitigation policies, while recognizing their unique social, cultural and economic roles, would make an important contribution towards reaching the temperature goal of the Paris Agreement and is vital for a limit of 1.5°C. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 1)'.

Global mapping of crop-specific emission factors highlights hotspots of nitrous oxide mitigation

Mitigating soil nitrous oxide (N₂O) emissions is essential for staying below a 2 °C warming threshold. However, accurate assessments of mitigation potential are limited by uncertainty and variability in direct emission factors (EFs). To assess where and why EFs differ, we created high-resolution maps of crop-specific EFs based on 1,507 georeferenced field observations. Here, using a data-driven approach, we show that EFs vary by two orders of magnitude over space. At global and regional scales, such variation is primarily driven by climatic and edaphic factors rather than the well-recognized management practices. Combining spatially explicit EFs with N surplus information, we conclude that global mitigation potential without compromising crop production is 30% (95% confidence interval, 17-53%) of direct soil emissions of N₂O, equivalent to the entire direct soil emissions of China and the United States combined. Two-thirds (65%) of the mitigation potential could be achieved on one-fifth of the global harvested area, mainly located in humid subtropical climates and across gleysols and acrisols. These findings highlight the value of a targeted policy approach on global hotspots that could deliver large N₂O mitigation as well as environmental and food co-benefits.

Decoupling between ammonia emission and crop production in China due to policy interventions

Cropland ammonia (NH₃ ) emission is a critical driver triggering haze pollution. Many agricultural policies were enforced in past four decades to improve nitrogen (N) use efficiency while maintaining crop yield. Inadvertent reductions of NH₃ emissions, which may be induced by such policies, are not well evaluated. Here, we quantify the China's cropland-NH₃ emission change from 1980 to 2050 and its response to policy interventions, using a data-driven model and a survey-based dataset of the fertilization scheme. Cropland-NH₃ emission in China doubled from 1.93 to 4.02 Tg NH₃ -N in period 1980-1996, and then decreased to 3.50 Tg NH₃ -N in 2017. The prevalence of four agricultural policies may avoid ~3.0 Tg NH₃ -N in 2017, mainly located in highly fertilized areas. Optimization of fertilizer management and food consumption could mitigate three-quarters of NH₃ emission in 2050 and lower NH₃ emission intensity (emission divided by crop production) close to the European Union and the United States. Our findings provide an evidence on the decoupling of cropland-NH₃ from crop production in China and suggest the need to achieve cropland-NH₃  mitigation while sustaining crop yields in other developing economies.

Deep mitigation of CO2 and non-CO2 greenhouse gases toward 1.5 °C and 2 °C futures

Stabilizing climate change well below 2 °C and towards 1.5 °C requires comprehensive mitigation of all greenhouse gases (GHG), including both CO₂ and non-CO₂ GHG emissions. Here we incorporate the latest global non-CO₂ emissions and mitigation data into a state-of-the-art integrated assessment model GCAM and examine 90 mitigation scenarios pairing different levels of CO₂ and non-CO₂ GHG abatement pathways. We estimate that when non-CO₂ mitigation contributions are not fully implemented, the timing of net-zero CO₂ must occur about two decades earlier. Conversely, comprehensive GHG abatement that fully integrates non-CO₂ mitigation measures in addition to a net-zero CO₂ commitment can help achieve 1.5 °C stabilization. While decarbonization-driven fuel switching mainly reduces non-CO₂ emissions from fuel extraction and end use, targeted non-CO₂ mitigation measures can significantly reduce fluorinated gas emissions from industrial processes and cooling sectors. Our integrated modeling provides direct insights in how system-wide all GHG mitigation can affect the timing of net-zero CO₂ for 1.5 °C and 2 °C climate change scenarios.

Waste-to-nutrition: a review of current and emerging conversion pathways

Residual biomass is acknowledged as a key sustainable feedstock for the transition towards circular and low fossil carbon economies to supply whether energy, chemical, material and food products or services. The latter is receiving increasing attention, in particular in the perspective of decoupling nutrition from arable land demand. In order to provide a comprehensive overview of the technical possibilities to convert residual biomasses into edible ingredients, we reviewed over 950 scientific and industrial records documenting existing and emerging waste-to-nutrition pathways, involving over 150 different feedstocks here grouped under 10 umbrella categories: (i) wood-related residual biomass, (ii) primary crop residues, (iii) manure, (iv) food waste, (v) sludge and wastewater, (vi) green residual biomass, (vii) slaughterhouse by-products, (viii) agrifood co-products, (ix) C₁ gases and (x) others. The review includes a detailed description of these pathways, as well as the processes they involve. As a result, we proposed four generic building blocks to systematize waste-to-nutrition conversion sequence patterns, namely enhancement, cracking, extraction and bioconversion. We further introduce a multidimensional representation of the biomasses suitability as potential as nutritional sources according to (i) their content in anti-nutritional compounds, (ii) their degree of structural complexity and (iii) their concentration of macro- and micronutrients. Finally, we suggest that the different pathways can be grouped into eight large families of approaches: (i) insect biorefinery, (ii) green biorefinery, (iii) lignocellulosic biorefinery, (iv) non-soluble protein recovery, (v) gas-intermediate biorefinery, (vi) liquid substrate alternative, (vii) solid-substrate fermentation and (viii) more-out-of-slaughterhouse by-products. The proposed framework aims to support future research in waste recovery and valorization within food systems, along with stimulating reflections on the improvement of resources' cascading use.

Social Character of Science and Its Connection to Epistemic Reliability

Scientific research is a human endeavour, performed by communities of people. Disproportionate focus on only some of the features related to this obvious fact has been used to discredit the reliability of scientific knowledge and to relativize its value when compared with knowledge stemming from other sources. This epistemic relativism is widespread nowadays and is arguably dangerous for our collective future, as the threat of climate change and its denialism clearly shows. In this work, we argue that even though the social character of science is indeed real, it does not entail epistemic relativism with respect to scientific knowledge, but quite the opposite, as there are several characteristic behaviours of this specific human community that were built to increase the reliability of scientific outputs. Crucially, we believe that present-day scientific education is lacking in the description and analysis of these particularities of the scientific community as a social group and that further investing in this area could greatly improve the possibilities of critical analysis of the often very technical issues that the citizens and future citizens of our modern societies have to confront.

Reconfiguring Food Systems Governance: The UNFSS and the Battle Over Authority and Legitimacy

The UN Food Systems Summit was an ambitious and hotly contested event that brought competing approaches to global food governance into relief. In this article, we unpack the rival visions that circulate around how food systems should be governed, focusing on two issues that we feel are at the heart of these divergences: authority and legitimacy. We illustrate how both corporate-philanthropic and food sovereignty networks are struggling to establish epistemic authority of food systems as well as produce legitimacy through very different approaches to participation and accountability.

South African Consumer Adoption of Plant-Based and Cultivated Meat: A Segmentation Study

The purpose of this study was to assess the likelihood of consumer adoption of plant-based and cultivated meat in South Africa as a pathway to a healthy, sustainable, and equitable food supply. We recruited a large sample of South Africans representative across age (18–61), gender, race, and income to participate in an online survey. Participants responded to a range of measures including adoption indicators, estimated yearly intake, motivators for purchasing, desired product characteristics, preferred species, and sociodemographics. We found a high degree of openness to both products. For plant-based meat, 67% were highly likely to try and 59% were highly likely to purchase. For cultivated meat, 60% were highly likely to try and 53% were highly likely to purchase. The highest acceptance was amongst the younger generations: 60% of born-frees, 62% of millennials, and 53% of Gen X were highly likely to purchase plant-based meat and 55% of born-frees, 55% of millennials, and 46% of Gen X were highly likely to purchase cultivated meat. For the general population, we observed that future meat intake was estimated to be split equally among the three meat categories (conventional, cultivated, and plant-based). We found early adopters (those highly likely to purchase) to be quite similar in attitudinal and sociodemographic characteristics in comparison to the general population. The study findings suggest that both plant-based and cultivated meat could be viable market-based options for improving the food system in South Africa, as consumers across all segments of society, and especially amongst the younger population, indicated broad acceptance.

World scientists' warnings into action, local to global

'We have kicked the can down the road once again - but we are running out of road.' - Rachel Kyte, Dean of Fletcher School at Tufts University.We, in our capacities as scientists, economists, governance and policy specialists, are shifting from warnings to guidance for action before there is no more 'road.' The science is clear and irrefutable; humanity is in advanced ecological overshoot. Our overexploitation of resources exceeds ecosystems' capacity to provide them or to absorb our waste. Society has failed to meet clearly stated goals of the UN Framework Convention on Climate Change. Civilization faces an epochal crossroads, but with potentially much better, wiser outcomes if we act now.What are the concrete and transformative actions by which we can turn away from the abyss? In this paper we forcefully recommend priority actions and resource allocation to avert the worst of the climate and nature emergencies, two of the most pressing symptoms of overshoot, and lead society into a future of greater wellbeing and wisdom. Humanity has begun the social, economic, political and technological initiatives needed for this transformation. Now, massive upscaling and acceleration of these actions and collaborations are essential before irreversible tipping points are crossed in the coming decade. We still can overcome significant societal, political and economic barriers of our own making.Previously, we identified six core areas for urgent global action - energy, pollutants, nature, food systems, population stabilization and economic goals. Here we identify an indicative, systemic and time-limited framework for priority actions for policy, planning and management at multiple scales from household to global. We broadly follow the 'Reduce-Remove-Repair' approach to rapid action. To guide decision makers, planners, managers, and budgeters, we cite some of the many experiments, mechanisms and resources in order to facilitate rapid global adoption of effective solutions.Our biggest challenges are not technical, but social, economic, political and behavioral. To have hope of success, we must accelerate collaborative actions across scales, in different cultures and governance systems, while maintaining adequate social, economic and political stability. Effective and timely actions are still achievable on many, though not all fronts. Such change will mean the difference for billions of children and adults, hundreds of thousands of species, health of many ecosystems, and will determine our common future.

Mapping the landscape of Consumer Food Waste

Since 2015 there has been a surge of academic publications and citations focused on consumer food waste. To introduce a special issue of Appetite focused on the drivers of consumer food waste we perform a transdisciplinary and historical review of the literature through a co-citation network analysis and topic modelling approach. We show that the rapid increase in publications is largely attributable to an urgency caused by the Sustainable Development Goals and climate change. Topic modelling reveals that the dramatic quantitative increase of publications has also produced a variety of evolving themes, and that a metaphorical Cambrian Explosion is occurring after decades of academic inactivity. Network analysis results show that consumer food waste features in thousands of articles and hundreds of journals, but that the citation practices of academics are becoming highly concentrated, as 20% of journals attract over 80% of citations. Finally, by examining the burstiness and transdisciplinary structure of citation networks we show that though the field has historically been dominated by empirical articles, it is now starting to show signs of maturity as a flurry of review papers help to consolidate knowledge.

Quantifying opportunities for greenhouse gas emissions mitigation using big data from smallholder crop and livestock farmers across Bangladesh

Climate change is and will continue to have significant implications for agricultural systems. While adaptation to climate change should be the priority for smallholder production systems, adoption of cost-effective mitigation options in agriculture not only contributes to food security but also reduces the extent of climate change and future adaptation needs. Utilizing management data from 16,413 and 12,548 crop and livestock farmers and associated soil and climatic data, we estimated GHG emissions generated from crop and livestock production using crop and livestock models, respectively. Mitigation measures in crop and livestock production, their mitigation potential and cost/benefit of adoption were then obtained from literature review, stakeholder consultations and expert opinion. We applied the identified mitigation measures to a realistic scale of adoption scenario in the short- (2030) and long-term (2050). Our results were then validated through stakeholders consultations. Here, we present identified mitigation options, their mitigation potentials and cost or benefit of adoption in the form of Marginal Abatement Cost Curves (MACC). Based on our analysis, total GHG emissions from agricultural sector in Bangladesh for the year 2014-15 is 76.79 million tonne (Mt) carbon-dioxide equivalent (CO₂e). Business-as-usual GHG emissions from the agricultural sector in Bangladesh are approximately 86.87 and 100.44 Mt CO₂e year^-1 by 2030 and 2050, respectively. Adoption of climate-smart crop and livestock management options to reduce emissions considering a realistic adoption scenario would offer GHG mitigation opportunities of 9.51 and 14.21 Mt CO₂e year^-1 by 2030 and 2050, respectively. Of this mitigation potential, 70-75% can be achieved through cost-saving options that could benefit smallholder farmers. Realization of this potential mitigation benefit, however, largely depends on the degree to which supportive policies and measures can encourage farmers' adoption of the identified climate smart agricultural techniques. Therefore, government should focus on facilitating uptake of these options through appropriate policy interventions, incentive mechanisms and strengthening agricultural extension programs.

Reducing Carbon Footprint Inequality of Household Consumption in Rural Areas: Analysis from Five Representative Provinces in China

Household consumption carbon footprint and inequality reductions are vital for a sustainable society, especially for rural areas. This study, focusing on rural China, one of the fastest growing economies with a massive population, explored the carbon footprint and inequality of household consumption using the latest micro household survey data of 2018 linked to environmental extended input--output analysis. The results show that in 2018 in rural China, the average household carbon footprint is 2.46 tons CO₂-eq per capita, which is around one-third of China's average footprint, indicating the large potential for further growth. Housing (45.32%), transportation (20.45%), and food (19.62%) are the dominant contributors to the carbon footprint. Meanwhile, great inequality, with a Gini coefficient of 0.488, among rural households is observed, which is largely due to differences in type of house built or purchased (explaining 24.44% of the variation), heating (18.10%), car purchase (12.44%), and petrol consumption (12.44%). Provinces, average education, and nonfarm income are among the important factors influencing the inequality. In the process of urbanization and rural revitalization, there is a high possibility that the household carbon footprint continues to increase, maintaining high levels of inequality. The current energy transition toward less carbon-intensive fuels in rural China is likely to dampen the growth rates of carbon footprints and potentially decrease inequality. Carbon intensity decrease could significantly reduce carbon footprints, but increase inequality. More comprehensive measures to reduce carbon footprint and inequality are needed, including transitioning to clean energy, poverty alleviation, reduction of income inequality, and better health care coverage.