Choosing the “least expensive” healthy food options could cut dietary emissions by one-third, according to a new study.

In addition to the lower emissions, diets composed of low-cost, healthy foods would cost roughly one-third as much as a diet of the most-consumed foods in every country.

The study, published in Nature Food, compares prices and emissions associated with 440 local food products in 171 countries.

The researchers identify some food groups that are low in both cost and emissions, including legumes, nuts and seeds, as well as oils and fats.

Some of the most widely consumed foods – such as wheat, maize, white beans, apples, onions, carrots and small fish – also fall into this category, the study says.

One of the lead authors tells Carbon Brief that while food marketing has promoted the idea that eating environmentally friendly diets is “very fancy and expensive”, the study shows that such diets are achievable through cheap, everyday foods.

Meanwhile, a separate Nature Food study found that reforming the policies that reduce taxes on meat products in the EU could decrease food-related emissions by up to 5.7%.

Costs and emissions

The study defines a healthy diet using the “healthy diet basket” (HDB), which is a standard based on nutritional guidelines that includes a range of food groups with the needed nutrients to provide long-term health.

Using both data on locally available products and food-specific emissions databases, the authors estimate the costs and greenhouse gas emissions of 440 food products needed for healthy diets in 171 countries.

They examine three different healthy diets: one using the most-consumed food products, one using the least expensive food products and one using the lowest-emitting food products.

Each of these diets is constructed for each country, based on costs, emissions, availability and consumption patterns.

The researchers find that a healthy diet comprising the most-consumed foods within each country – such as beef, chicken, pork, milk, rice and tomatoes – emits an average of 2.44 kilograms of CO2-equivalent (kgCO2e) and costs $9.96 (£7.24) in 2021 prices, per person and per day.

However, they find that a healthy diet with the least-expensive locally available foods in each country – such as bananas, carrots, small fish, eggs, lentils, chicken and cassava – emits 1.65kgCO2e and costs $3.68 (£2.68). That is approximately one-third of the emissions and one-third of the cost of the most-consumed products diet.

In comparison, a healthy diet with the lowest-emissions products – such as oats, tuna, sardines and apples – would emit just 0.67kgCO2e, but would cost nearly double the least-expensive diet, at $6.95 (£5.05).

This reveals the tradeoffs of affordability and sustainability – and shows that the least-expensive foods tend to produce lower emissions, according to the study.

Dr Elena Martínez, a food-systems researcher at Tufts University and one of the lead authors of the study, tells Carbon Brief this is generally true because lower-cost food production tends to use fewer fossil fuels and require less land-use change, which also cuts emissions.

Ignacio Drake is coordinator of the fiscal and economic policies at Colansa, an organisation promoting healthy eating and sustainable food systems in Latin America and the Caribbean.

Drake, who was not involved in the study, tells Carbon Brief that the research is a “step further” than previous work on healthy diets. He adds that the study “integrates and consolidates” previous analyses done by other groups, such as the World Bank and the UN Food and Agriculture Organization.

Food group differences

The research looks at six food groups: animal-sourced foods, oils and fats, fruits, legumes (as well as nuts and seeds), vegetables and starchy staples.

Animal-sourced foods – such as meat and dairy – are typically the most-emitting, and most-expensive, food group.

Within this group, the study finds that beef has the highest costs and emissions, while small fish, such as sardines, have the lowest emissions. Milk and poultry are amongst the least-expensive products for a healthy diet.

Starchy staple products also contribute to high emissions too, adds the study, because they make up such a large portion of most people’s calories.

Emissions from fruits, vegetables, legumes and oil are lower than those from animal-derived foods.

The following chart shows the energy contributions (top) and related emissions (bottom) from six major food groups in the three diets modelled by the study: lowest-cost (left), lowest-emission (middle) and most-common (right) food items.

The six food groups examined in the study are shown in different colours: animal-sourced foods (red), legumes, nuts and seeds (blue), oils and fats (purple), vegetables (green), fruits (orange) and starchy staples (yellow). The size of each box represents the contribution of that food to the overall dietary energy (top) and greenhouse gas emissions (bottom) of each diet.

Prof William Masters, a professor at Tufts University and author on the study, tells Carbon Brief that balancing food groups is important for human health and the environment, but local context is also important. For example, he points out that in low-income countries, some people do not get enough animal-sourced foods.

For Drake, if there are foods with the same nutritional quality, but that are cheaper and produce fewer emissions, it is logical to think that the “cost-benefit ratio [of switching] is clear”.

Other studies and reports have also modelled healthy and sustainable diets and, although they do not exclude animal-sourced foods, they do limit their consumption.

A recent study estimated that a global food system transformation – including a diet known as the “planetary health diet”, based on cutting meat, dairy and sugar and increasing plant-based foods, along with other actions – can help limit global temperature rise to 1.85C by 2050.

The latest EAT-Lancet Commission report found that a global shift to healthier diets could cut non-CO2 emissions from agriculture, such as methane and nitrous oxide, by 15%. The report recommends increasing the production of fruit, vegetable and nuts by two-thirds, while reducing livestock meat production by one-third.

Dr Sonia Rodríguez, head of the department of food, culture and environment at Mexico’s National Institute of Public Health, says that unlike earlier studies, which project ideal scenarios, this new study also evaluates real scenarios and provides a “global view” of the costs and emissions of diets in various countries.

Increasing access

The study points out that as people’s incomes increase, their consumption of expensive foods also increases. However, it adds, some people with high income that can afford healthy diets often consume other types of foods, due to reasons such as preferences, time and cooking costs.

The study stresses that nearly one-third of the world’s population – about 2.6 billion people – cannot afford sufficient food products required for a healthy diet.

In low-income countries, primarily in sub-Saharan Africa and south Asia, 75% of the population cannot afford a healthy diet, says the study.

In middle-income countries, such as China, Brazil, Mexico and Russia, more than half of the population can afford such a diet.

To improve the consumption of healthy, sustainable and affordable foods, the authors recommend changes in food policy, increasing the availability of food at the local level and substituting highly emitting products.

Martínez also suggests implementing labelling systems with information on the environmental footprint and nutritional quality of foods. She adds:

“We need strategies beyond just reducing the cost of diets to get people to eat climate-friendly foods.”

Drake notes that there are public and financial policies that can help reduce the consumption of unhealthy and unsustainable foods, such as taxes on unhealthy foods and sugary drinks. This, he adds, would lead to better health outcomes for countries and free up public resources for implementing other policies, such as subsidies for producing healthy food.

Separately, another recent Nature Food study looks at taxes specifically on meat products, which are subject to reduced value-added tax (VAT) in 22 EU member states.

It finds that taxing meat at the standard VAT rate could decrease dietary-related greenhouse gases by 3.5-5.7%. Such a levy would also have positive outcomes for water and land use, as well as biodiversity loss, according to the study.

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The post Adopting low-cost ‘healthy’ diets could cut food emissions by one-third appeared first on Carbon Brief.

Adopting low-cost ‘healthy’ diets could cut food emissions by one-third

As a treaty to protect the High Seas entered into force this month with backing from more than 80 countries, major fishing nations China, Japan and Brazil secured a last-minute seat at the table to negotiate the procedural rules, funding and other key issues ahead of the treaty’s first COP.

The Biodiversity Beyond National Jurisdiction (BBNJ) pact – known as the High Seas Treaty – was agreed in 2023. It is seen as key to achieving a global goal to protect at least 30% of the planet’s ecosystems by 2030, as it lays the legal foundation for creating international marine protected areas (MPAs) in the deep ocean. The high seas encompass two-thirds of the world’s ocean.

Last September, the treaty reached the key threshold of 60 national ratifications needed for it to enter into force – a number that has kept growing and currently stands at 83. In total, 145 countries have signed the pact, which indicates their intention to ratify it. The treaty formally took effect on January 17.

“In a world of accelerating crises – climate change, biodiversity loss and pollution – the agreement fills a critical governance gap to secure a resilient and productive ocean for all,” UN Secretary-General António Guterres said in a statement.

Julio Cordano, Chile’s director of environment, climate change and oceans, said the treaty is “one of the most important victories of our time”. He added that the Nazca and Salas y Gómez ridge – off the coast of South America in the Pacific – could be one of the first intact biodiversity hotspots to gain protection.

Scientists have warned the ocean is losing its capacity to act as a carbon sink, as emissions and global temperatures rise. Currently, the ocean traps around 90% of the excess planetary heat building up from global warming. Marine protected areas could become a tool to restore “blue carbon sinks”, by boosting carbon absorption in the seafloor and protecting carbon-trapping organisms such as microalgae.

Last-minute ratifications

Countries that have ratified the BBNJ will now be bound by some of its rules, including a key provision requiring countries to carry out environmental impact assessments (EIA) for activities that could have an impact on the deep ocean’s biodiversity, such as fisheries.

Activities that affect the ocean floor, such as deep-sea mining, will still fall under the jurisdiction of the International Seabed Authority (ISA).

Nations are still negotiating the rules of the BBNJ’s other provisions, including creating new MPAs and sharing genetic resources from biodiversity in the deep ocean. They will meet in one last negotiating session in late March, ahead of the treaty’s first COP (conference of the parties) set to take place in late 2026 or early 2027.

China and Japan – which are major fishing nations that operate in deep waters – ratified the BBNJ in December 2025, just as the treaty was about to enter into force. Other top fishing nations on the high seas like South Korea and Spain had already ratified the BBNJ last year.

Power play: Can a defensive Europe stick with decarbonisation in Davos?

Tom Pickerell, ocean programme director at the World Resources Institute (WRI), said that while the last-minute ratifications from China, Japan and Brazil were not required for the treaty’s entry into force, they were about high-seas players ensuring they have a “seat at the table”.

“As major fishing nations and geopolitical powers, these countries recognise that upcoming BBNJ COP negotiations will shape rules affecting critical commercial sectors – from shipping and fisheries to biotechnology – and influence how governments engage with the treaty going forward,” Pickerell told Climate Home News.

Some major Western countries – including the US, Canada, Germany and the UK – have yet to ratify the treaty and unless they do, they will be left out of drafting its procedural rules. A group of 18 environmental groups urged the UK government to ratify it quickly, saying it would be a “failure of leadership” to miss the BBNJ’s first COP.

Finalising the rules

Countries will meet from March 23 to April 2 for the treaty’s last “preparatory commission” (PrepCom) session in New York, which is set to draft a proposal for the treaty’s procedural rules, among them on funding processes and where the secretariat will be hosted – with current offers coming from China in the city of Xiamen, Chile’s Valparaiso and Brussels in Belgium.

Janine Felson, a diplomat from Belize and co-chair of the “PrepCom”, told journalists in an online briefing “we’re now at a critical stage” because, with the treaty having entered into force, the preparatory commission is “pretty much a definitive moment for the agreement”.

Felson said countries will meet to “tidy up those rules that are necessary for the conference of the parties to convene” and for states to begin implementation. The first COP will adopt the rules of engagement.

She noted there are “some contentious issues” on whether the BBNJ should follow the structure of other international treaties such as the Convention on Biological Diversity (CBD), as well as differing opinions on how prescriptive its procedures should be.

“While there is this tension on how far can we be held to precedent, there is also recognition that this BBNJ agreement has quite a bit to contribute in enhancing global ocean governance,” she added.

The post Big fishing nations secure last-minute seat to write rules on deep sea conservation appeared first on Climate Home News.

Big fishing nations secure last-minute seat to write rules on deep sea conservation

The annual World Economic Forum got underway on Tuesday in the Swiss ski resort of Davos, providing a snowy stage for government and business leaders to opine on international affairs. With attention focused on the latest crisis – a potential US-European trade war over Greenland – climate change has slid down the agenda.

Despite this, a number of panels are addressing issues like electric vehicles, energy security and climate science. Keep up with top takeaways from those discussions and other climate news from Davos in our bulletin, which we’ll update throughout the day.

From oil to electrons – energy security enters a new era

Energy crises spurred by geopolitical tensions are nothing new – remember the 1970s oil shock spurred by the embargo Arab producers slapped on countries that had supported Israel during the Yom Kippur War, leading to rocketing inflation and huge economic pain.

But, a Davos panel on energy security heard, the situation has since changed. Oil now accounts for less than 30% of the world’s energy supply, down from more than 50% in 1973. This shift, combined with a supply glut, means oil is taking more of a back seat, according to International Energy Agency boss Fatih Birol.

Instead, in an “age of electricity” driven by transport and technology, energy diplomacy is more focused on key elements of that supply chain, in the form of critical minerals, natural gas and the security buffer renewables can provide. That requires new thinking, Birol added.

“Energy and geopolitics were always interwoven but I have never ever seen that the energy security risks are so multiplied,” he said. “Energy security, in my view, should be elevated to the level of national security today.”

In this context, he noted how many countries are now seeking to generate their own energy as far as possible, including from nuclear and renewables, and when doing energy deals, they are considering not only costs but also whether they can rely on partners in the long-term.

In the case of Europe – which saw energy prices jump after sanctions on Russian gas imports in the wake of Moscow’s invasion of Ukraine – energy security rooted in homegrown supply is a top priority, European Commission President Ursula von der Leyen said in Davos on Tuesday.

Outlining the bloc’s “affordable energy action plan” in a keynote speech at the World Economic Forum, she emphasised that Europe is “massively investing in our energy security and independence” with interconnectors and grids based on domestically produced sources of power.

The EU, she said, is trying to promote nuclear and renewables as much as possible “to bring down prices and cut dependencies; to put an end to price volatility, manipulation and supply shocks,” calling for a faster transition to clean energy.

“Because homegrown, reliable, resilient and cheaper energy will drive our economic growth and deliver for Europeans and secure our independence,” she added.

Comment – Power play: Can a defensive Europe stick with decarbonisation in Davos?

AES boss calls for “more technical talk” on supply chains

Earlier, the energy security panel tackled the risks related to supply chains for clean energy and electrification, which are being partly fuelled by rising demand from data centres and electric vehicles.

The minerals and metals that are required for batteries, cables and other components are largely under the control of China, which has invested massively in extracting and processing those materials both at home and overseas. Efforts to boost energy security by breaking dependence on China will continue shaping diplomacy now and in the future, the experts noted.

Copper – a key raw material for the energy transition – is set for a 70% increase in demand over the next 25 years, said Mike Henry, CEO of mining giant BHP, with remaining deposits now harder to exploit. Prices are on an upward trend, and this offers opportunities for Latin America, a region rich in the metal, he added.

At ‘Davos of mining’, Saudi Arabia shapes new narrative on minerals

Andrés Gluski, CEO of AES – which describes itself as “the largest US-based global power company”, generating and selling all kinds of energy to companies – said there is a lack of discussion about supply chains compared with ideological positioning on energy sources.

Instead he called for “more technical talk” about boosting battery storage to smooth out electricity supply and using existing infrastructure “smarter”. While new nuclear technologies such as small modular reactors are promising, it will be at least a decade before they can be deployed effectively, he noted.

In the meantime, with electricity demand rising rapidly, the politicisation of the debate around renewables as an energy source “makes no sense whatsoever”, he added.

The post Climate at Davos: Energy security in the geopolitical driving seat  appeared first on Climate Home News.

Climate at Davos: Energy security in the geopolitical driving seat