The food we eat has a critical impact on human and planetary health. Food systems are responsible for approximately a third of total global greenhouse gas emissions (GHGEs). This review summarises studies that have measured dietary GHGEs and assessed their associations with various demographic variables. Most studies report dietary emissions at the individual level, but some studies use households as the unit of analysis. Studies investigating individuals estimate dietary intakes using 24-hour dietary recalls, food frequency questionnaires, diet history interviews, food diaries or other dietary records. Studies investigating households rely on food purchasing data and expenditure surveys. The majority of studies estimate dietary GHGEs using process-based life cycle assessments. It is difficult to directly compare emissions estimates between studies at either the individual or household-level due to methodological differences. In general, there are mixed findings with regards to the relationships between various demographic variables and dietary emissions, although older adults generally had higher dietary GHGEs than younger adults, and men typically had higher dietary GHGEs than women, even when standardizing for total energy intake. This review may be useful in informing and targeting policies and interventions to reduce GHGEs of dietary intake.

Climate change stands as the paramount challenge confronting humanity in the contemporary era. Attempting to address the problem, the main sectors responsible for it have been subject to domestic or international policies and laws aimed at reducing greenhouse gas (GHG) emissions, except one: livestock. Given that animal-sourced food production contributes a large portion of GHG emissions, this Article aims to analyze the impacts that the exclusion of the livestock sector, in efforts to tackle climate change, would have on compliance with international treaties on the subject, especially the Paris Agreement. One conclusion reveals that state parties, by ignoring the sector, will violate several articles of the Agreement, which will likely lead to the failure of its main purpose of holding the increase in the global average temperature to well below 2°C.

Net zero greenhouse gas emissions by 2050, the UK’s current target, requires bridging a dramatic energy transition and eliminating all other net sources of emissions while ensuring a just transition. Key components like renewable electricity generation and electric vehicles are well developed, but many issues remain. Public support for a green economy may wane if the economic costs are too high or seen as unfair. Therefore, although renewable energy is cheaper than fossil fuels, it is essential to maintain employment, real per capita growth and reduced inequality. Decarbonizing the UK economy requires an integrated sequential approach and need not be delayed while dealing with the aftermath of the COVID-19 pandemic, energy crisis and resulting inflation.

New Zealand has committed to a 50% reduction in greenhouse gas emissions (GHGEs) from 2005 levels by 2030. Dietary changes within New Zealand could simultaneously improve population health and contribute towards the nation’s emissions reduction target, as agricultural emissions are estimated to account for half of New Zealand’s GHGEs(1). This research aimed to quantify the GHGEs associated with household purchases of major food groups in New Zealand and identify the sociodemographic characteristics that are associated with per capita household dietary emissions. Household dietary emissions were estimated using the NielsenIQ Homescan(R) consumer panel — a large sample of households within New Zealand who report purchasing data of take-home food and beverages. The sample is nationally representative in terms of broad geographical regions and selected key demographic characteristics. Carbon emission estimates were assigned to 1,908,485 total food and beverage purchases from 1,775 households over one year (2019) using a process-based life cycle assessment (LCA) dataset initially constructed in the United Kingdom (UK) and adapted for New Zealand(2). This LCA dataset contains estimates of greenhouse gas emissions generated over the life cycle of the production of food products from the following stages: farming and processing, transit packaging, consumer packaging, transport, warehouse and distribution, refrigeration, and overheads. Greenhouse gas emissions are expressed in kg of carbon dioxide equivalents per kg of food product over a 100-year time horizon. Total emissions from purchases of major food groups were then estimated. Multiple linear regression was used to examine the relationships between household variables and per capita dietary emissions. Overall purchases of red and processed meat (35%) and dairy products (19%) were responsible for the greatest proportion of emissions. The age group of the primary household shopper as well as household size were predictors of per capita dietary emissions — households with primary shoppers > 65 years had, on average, 33% (95% CI: 20% to 49%) higher per capita dietary emissions, compared to households with primary shoppers 34 years; and every additional household member was associated with, on average, 11% (95% CI: 9% to 13%) lower per capita dietary emissions. We have shown in this large representative sample of New Zealand households that purchases of just two food groups — red and processed meat, and dairy — were responsible for approximately half of dietary greenhouse gas emissions. Larger households had lower per capita dietary greenhouse gas emissions, and older shoppers had relatively higher greenhouse gas emissions. Whilst similar associations have been reported elsewhere more research is needed to confirm these latter findings. With enhanced understanding of the observed association between age of a household’s primary shopper and per capita dietary emissions, interventions may be devised that encourage shoppers to purchase lower-emitting foods, particularly less meat and dairy.

This paper defends strong emissions sufficientarianism as an approach to assigning moral rights to generate greenhouse gas emissions. Strong emissions sufficientarianism holds that only subsistence emitting is morally permissible. This paper argues that, since it is uncertain how many subsistence emissions there will be, the present generation owes it to future generations to refrain from generating non-subsistence emissions, not to risk imposing on them a tragic choice between sacrificing themselves and contributing to very dangerous climate change. The paper also addresses the charge that emissions sufficientarianism, in general, is too permissive since it entails a right to contribute to very dangerous climate change. The overall message is that, given the moral urgency posed by climate change, there is little room for distributive principles besides emissions sufficientarianism. This casts doubt on the appropriateness of relying on carbon budgets in assigning rights to emit.

The objective was to evaluate steer performance, meat nutritional value, land-use, food–feed competition and both economic and environmental sustainability within temperate pasture-based suckler weanling-to-beef systems with or without (forage-only) concentrates. Post-weaning, 8-month-old, late-maturing breed steers (333 kg) were assigned to one of three systems: (1) grass silage + 1.2 kg concentrate DM (148 days), followed by pasture (123 days) and finished on ad libitum concentrates (120 days) – slaughter age, 21 months (GRAIN); (2) as per (1) but pasture (196 days) and finished on grass silage ad libitum + 3.5 kg concentrate DM (124 days) – slaughter age, 24 months (SIL + GRAIN); and (3) grass silage-only (148 days), pasture (196 days), silage-only (140 days) and finished on pasture (97 days) – slaughter age, 28 months (FORAGE). The mean target carcass weight was 390 kg for each system. Data generated were used to parameterize a farm-level beef systems model. Concentrate DM intake was 1187, 606 and 0 kg/head for GRAIN, SIL + GRAIN and FORAGE, respectively. The forage-only (FORAGE) system offers several advantages, including improved farm profitability, enhanced meat fatty acid profile and only utilized inedible human feed. Consequently, associated greenhouse gas (GHG) emissions per net human edible food produced were more favourable for FORAGE. However, compared to GRAIN, the FORAGE system had an older age at slaughter and associated increased pasture land-use and GHG emissions per animal, meat weight gain and essential amino acids gain. There are therefore inevitable trade-offs, as one beef system does not improve all sustainability and GHG emission metrics.

Measuring and attributing greenhouse gas (GHG) emissions remains a challenging problem as the world strives toward meeting emissions reductions targets. As a significant portion of total global emissions, the road transportation sector represents an enormous challenge for estimating and tracking emissions at a global scale. To meet this challenge, we have developed a hybrid approach for estimating road transportation emissions that combines the strengths of machine learning and satellite imagery with localized emissions factors data to create an accurate, globally scalable, and easily configurable GHG monitoring framework.

The Mediterranean diet is often proposed as a sustainable diet model. This study aimed to evaluate the associations between adherence to the Mediterranean diet and sustainability domains in a cohort of French adults, using multiple criteria including nutritional quality, environmental pressures, monetary cost and dietary pesticide exposure. Food intakes of 29 210 NutriNet-Santé volunteers were assessed in 2014 using a semi-quantitative FFQ. Adherence to the Mediterranean diet was evaluated using the validated literature-based adherence score (MEDI-LITE). The associations between the MEDI-LITE and various sustainability indicators were examined using ANCOVA models, adjusted for sex, age and energy intake. Higher adherence to the MEDI-LITE was associated with higher nutritional quality scores, better overall nutrient profile as well as reduced environmental impact (land occupation: Q5 v. Q1: −35 %, greenhouse gas emissions: −40 % and cumulative energy demand: −17 %). In turn, monetary cost increased with increasing adherence to the Mediterranean diet (Q5 v. Q1: +15 %), while higher adherents to the Mediterranean diet had overall higher pesticide exposure due to their high plant-based food consumption. In this large cohort of French adults, greater adherence to the Mediterranean diet was associated with nutritional and environmental benefits, but also with higher monetary cost and greater exposure to pesticides, illustrating the necessity to develop large-scale strategies for healthy, safe (pesticide- and contaminant-free) and environmentally sustainable diets for all.

Agricultural emissions in most countries have been increasing against a backdrop of decreasing non-agricultural emissions. The climate change treaties contain a qualification that appears to exempt the agricultural sector from mitigation of greenhouse gas emissions where there is a ‘threat to food production’. This potential mitigation exception gives rise to the risk that states will invoke a threat to food production in order to shield their agricultural sector from intensifying mitigation pressure. A systematic analysis of documentation issued pursuant to the climate treaties reveals that many states, both developed and developing, have made statements suggesting that their agricultural sector is relieved of some or all of the pressure placed on other economic sectors to deliver mitigation outcomes. However, this concern that mitigation of agricultural emissions will threaten food production is only weakly supported, even as it threatens achievement of the Paris Agreement's goal of keeping global warming ‘well below 2°C’.

The climate justice literature typically endorses a moral right to produce subsistence emissions, but this right appears problematic considering how urgent it has become to reduce all emissions. It seems that we are currently facing a dilemma between respecting people's right to subsistence and keeping emissions within a reasonably safe budget. This article argues, however, that there is no reason why a moral permission to produce subsistence emissions must be accompanied by an exemption from responsibility. Even when we are dealing with subsistence emissions, we can demand that people correct for having emitted if they can do so without jeopardizing their own vital interests. This reduces the tension between the right to produce subsistence emissions and avoiding very significant climate change. If many emitters offset their subsistence emissions or contribute to adaptation and compensation because of them, the negative consequences of recognizing this right are tempered when it comes to both mitigating climate change and responding to its adverse effects.

A future sustainable dietary pattern for Japanese is yet undefined. This study aimed to explore more sustainable Japanese diets that are nutritious, affordable and with low greenhouse gas emissions (GHGE) and particular emphasis on cultural acceptability. A newly developed data envelopment analysis (DEA) diet model was applied to 4-d dietary record data among 184 healthy Japanese men and 185 women volunteers aged 21–69 years. Alternative diets were calculated as the linear combinations of observed diets. Firstly, for each individual, four modelled diets were calculated that maximised cultural acceptability (i.e. minimise dietary change from observed diet), maximised nutritional quality assessed by the Nutrient-Rich Food Index (NRF), minimised monetary diet costs or minimised diet-related GHGE. The final modelled diet combined all four indicators. In the first four models, the largest improvement was obtained for each targeted indicator separately, while relatively small improvements or unwanted changes were observed for other indicator. When all indicators were aimed to optimise, the NRF score and diet-related GHGE were improved by 8–13 % with the lower monetary cost than observed diets, although the percentage improvement was a bit smaller than the separate models. The final modelled diets demanded increased intakes for whole grains, fruits, milk/cream/yogurt, legumes/nuts, and decreased intakes for red and processed meat, sugar/confectioneries, alcoholic and sweetened beverages, and seasonings in both sexes. In conclusion, more sustainable dietary patterns considering several indicators are possible for Japanese, while total improvement is moderate due to trade-offs between indicators and methodological limitation of DEA diet model.