Ingredient swaps to reduce carbon emissions from food

We discovered which ingredients were climate-friendly in a previous blog post, so now we are deep diving into ingredients you can swap, instead of choosing high-emitting products in your recipes. Prepare to receive some practical tips! 

Animal products 🐮

Fish

Two of the main factors affecting the climate impact of sea creatures are the fishing area and the fishing method. This is due to the fact that the highest emissions in capture fisheries come from fuel use (≈ 70%) (1). Therefore, species living off-shore and/or in the deep-sea tend to have a higher impact with respect to fishes habiting coastal areas. When it comes to the fishing gears, trawling and longlining lead to higher emissions with respect to the seining method. 

Longlining: uses baited hooks on offshoots of a single main line. Midwater longlining unfortunately can catch other sea life and birds. Bottom longlining is more respectful for the sea bed than trawling, so it is a more environmentally sound method for demersal species. 

Seining: purse seines are walls of netting used to encircle entire schools of fish at or near the surface. 

Trawling: towing a net through water. Bottom trawling is the method of fishing responsible for the greatest environmental damage, as the net is weighted down with heavy cables and rollers over the ocean floor, scraping everything in its path.

Some swaps you can do is to choose fish that swim at the surface of the water or seafoods like mussels that have a low carbon footprint since, even if farmed, they do not require feed. 

Eggs

Feed inputs make the greatest contribution to carbon emissions, and are therefore the main factor influencing the carbon footprint of egg production systems.

Instead, you can use aquafaba which produces 0 kg CO2e! Yes, you read that correctly. At the point of chickpea cooking, the cooking water is usually treated as waste. Therefore, the environmental burdens of chickpea cultivation and processing is entirely attributed to the cooked chickpeas, leaving the unprocessed aquafaba as a burden-free product (2).

Dairy 🧀

The farming stage, and in particular cow rearing for milk production, is the most impacting stage of dairy products in terms of greenhouse gas emissions (as well as nutrient pollution and land use). This is due to enteric fermentation (the microbial decomposition of feed in the rumen of the animal that is released as burps) and fertilisers used for feed production which release methane and nitrous oxide respectively. 

In addition, dairy products require large amounts of raw milk and energy for processing. Butter, in particular, requires up to 10-20 kg raw milk per kg of butter! (3) 

The best way to reduce the carbon impact of dairy products is to use vegan alternatives of the same product. Plant-based milk and cheese alternatives as well as nutritional yeast are good swaps for milk and cheese. 

Now you may wonder which type of plant-based milk alternatives you should choose. Don’t worry too much about that since all plant based milks release between 60-80% less emissions than cow milk (4). Differences among plant-based milks are due to the country of production of the raw material, the amount of fertiliser used or the need for electricity to power irrigation pumps.

Condiments 🧂

Olive oil

The relatively high impact of olive oil production lies in the olive cultivation which needs multiple plant protection treatments (which means high fuel use from the use of machinery). On average, most machinery used is also quite old (15-20 years) which leads to even higher fuel emissions. The milling phase typically uses traditional extraction processes which means that low amounts of olive are pressed into olive oil at the time increasing the energy requirements. Finally, 20% of the total climate impact of olive oil is due to its packaging in glass bottles (5). Switching to sunflower oil will result in a significant carbon saving of 48%. 

Bearnaise sauce

CO2e emissions of sauces increase when adding animal products, such as eggs and dairy. So rather, choose a sauce that contains less animal products, or the best is to opt for a vegan option in order to reduce the carbon footprint.

Beef stock

Beef stock has a high carbon impact due to the dehydration process which requires a considerable amount of energy and also because it is an animal product. Vegetable stock still has a fairly high carbon footprint but in comparison to beef it is much lower (6). 

Carbohydrates 🥔

Rice 

Rice cultivation is responsible for 10-13% of worldwide methane emissions (7), making it the worst carbohydrate for the climate. This is due to methanotrophs (soil microorganisms) in the paddy fields producing the strong greenhouse gas methane. Some easy ingredients swaps you can do with their carbon savings:

• Quinoa: 57%
• Bulgur/couscous: 74%
• Potato: 93%

Fruit & Vegetables 🍎

Raisins

Dried produce (e.g. raisins and other dried fruits such as dried apricots, banana, mango, dried chilli peppers etc.) have a higher carbon footprint compared to fresh food. In the drying process a considerable amount of water is removed, therefore, to make 1kg of dried fruit, you need between 1.5-4 kg of fresh produce (8). In addition, unless sun-drying, energy is required for the drying process. 

All nuts have low CO2e emissions and are good alternatives to dried fruits. Peanuts for example have slightly lower CO2e emissions than other tree nuts (9). Did you know that peanuts are classified as a legume crop and not tree nuts? Legumes have the special ability to fix nitrogen from the atmosphere into the soil, and therefore they need lower amounts of  nitrogen fertiliser. They also require less irrigation which means that energy and machineries are used at a lower rate.

Greenhouse vs open field 

The rule of thumb when it comes to sourcing fruit and vegetables is to make sure they are grown in an open field. Heated greenhouses require significant energy for heating and lighting, resulting in higher carbon emissions. It’s worth noting that transportation (excluding air-travel) accounts for only around 6% of the overall carbon footprint of most food products, so country of origin plays little (10). 

To wrap it all up 🌯

Here are some key takeaways:

• Choose fish that swim at the surface of the water.
• Chickpea cooking water is treated as waste (the cultivation and processing of the chickpeas is unaccounted), therefore unprocessed aquafaba as an egg replacement has zero carbon footprint making it super sustainable!
• To produce 1 kg of butter you need 10-20kg of raw milk. Opt instead for vegan alternatives. 
• Dehydration of fruits or stock requires a lot of energy. For dried fruits opt for fresh fruits or walnuts/peanuts instead. 
• Rice cultivation is responsible for 10-13% of worldwide methane emissions. Swap to bulgur, couscous, quinoa or potatoes instead. 
• Choose fruit and vegetables that are grown in an open field rather than in a heated greenhouse. Local isn’t necessarily better so if that product isn’t in season in your country, choose the same product from a country where it is in season (avoid air-travel though).

Interested in making more sustainable recipes? Sign up here to start using Klimato's carbon footprint calculator. 

Sources:

1. Ziegler, et al., 2013
2. Saget, et al., (2021) and International Reference Life Cycle Data System (ILCD) methodology on multi-products processes.
3. Flysjö, 2012, or Djekic, et al., 2014
4. Singh-Povel, et al., 2022
5. Pattara, et al., (2016)
6. Milà i Canals, et al., (2011)
7. Neue, 1997
8. Frankowska, et al., (2019).
9. Volpe et al, 2015.
10. Poore, et al., 2018

Ingredient swaps table:

Klimato database 
Clune et al., 2017
Iribarren et al., 2010 
Hornborg et al., 2022
Oatly
Violife