2023 update: Check out this blog by Evan Peters who further discusses the carbon impact of macadamia nuts as compared to other dietary and lifestyle choices.
As consumers, we’ve become a lot more environmentally conscious when it comes to our food choices. We’re thinking more about where our food comes from, whether it’s organically and ethically produced, and what the carbon footprint is.
This is great news for the environment, given food accounts for 26% of global greenhouse gas (GHG) emissions.
In this blog post, we want to focus on the environmental benefits of incorporating more nuts into your diet. But as we go on to see, not all nuts are created equal.
Nuts have a lower carbon footprint than animal-based proteins
Nuts and other plant-based protein sources, such as tofu and beans, have a far lower GHG emission count compared to animal-based food products.
As can be seen in the graph below, on average, nuts emit just 0.26kg CO2eq per 100 grams of protein. Meanwhile, beef emits a whopping 49.89kg CO2eq and lamb and mutton emit 20kg CO2eq per 100 grams of protein. While poultry and eggs emit a much lower carbon footprint than other animal-based proteins, at 5.7kg and 4.21kg CO2eq respectively, they still have a much higher GHG emission count than nuts.
Source: Our World in Data
But why the difference?
For many foods - and particularly those with a higher carbon footprint - most GHG emissions result from land use change and from farming processes, such as the application of fertilisers (both organic and synthetic) and the production of methane in the stomachs of cattle. Together, land use and farm-stage emissions account for more than 80% of the carbon footprint for most foods.
Nuts and other plant-based sources, on the other hand, require far less intensive farming methods. Therefore, the biggest difference we can make as consumers is to reduce our consumption of animal-based proteins and eat more plant-based proteins, including nuts!
But not all nuts are created equal...
Though nuts have a much lower carbon footprint than animal-based products, not all nuts are created equal when it comes to sustainability.
Groundnuts, legumes (e.g. peanuts) and tree nuts (e.g. macadamia nuts) all involve different types of farming processes. The production of tree nuts means less GHG emissions per 100g protein because the trees themselves absorb carbon from the atmosphere.
However, some tree nuts are still more sustainable than others.
Almonds are often considered less environmentally friendly because they require a lot of water to reach maturity. It takes a gallon (4.6 litres) of water to produce each and every almond. 82% of the world’s almonds are produced in California, and as the state continues to battle droughts, you can guess where the finger of blame tends to be pointed.
Almond production can also be disruptive to ecosystems and have a severe strain on bee populations. Bees may be harmed or killed during cross-country transportation for intense pollination practices, which can also lead to spreading diseases and illnesses to other colonies.
But does this mean you shouldn’t eat almonds? At the end of the day, the production of almonds still takes a significantly lower toll on the environment than meat production. And steps are being taken to try and reduce water consumption in almond production. Many almond farmers in California have introduced drip-irrigation systems which cuts water usage by supplying plants with smaller, targeted amounts.
At the other end of the spectrum, macadamia nuts, hazelnuts and brazil nuts are great examples of sustainable food production because they require little water and minimal upkeep. Brazil nuts also support the rainforest and reduce deforestation.
According to Healabel, each of these nuts use 2kg CO2eq to produce 1kg, which is the equivalent to a car driving 5 miles. Almonds in fact, have a higher carbon footprint, requiring 3.56kg CO2eq to produce 1kg. Walnuts and pistachios actually have the lowest carbon footprint, emitting 0.76kg CO2eq and 1.1kg CO2eq respectively, to produce 1kg of product.
But macadamia nuts, in particular, have the potential to have a much lower level of GHG emissions by way of Climate Smart Macadamia Agroforestry (CSMA), a system pioneered by HIMACUL farmers with the guidance of The Neno Macadamia Trust (NMT).
Climate Smart Macadamia Agroforestry (CSMA)
Trees produce oxygen and sequester CO2, and therefore deforestation increases the problem of CO2 emission. Agroforestry is the use of trees to provide food but the trees also sequester (absorb) CO2. The Neno Macadamia Trust is focusing on building and promoting agroforestry as a way to reverse deforestation and also mitigate CO2 emission damage.
Farmers who have for years been in a downward spiral of reduced resilience following climate and economic shocks, including droughts, cyclones, floods and now Covid-19, now have the opportunity to reverse this negative socially, financially, and environmentally damaging cycle. To find out more about CO2 sequestration by macadamia trees, visit the NMT website.
So what's the takeaway here? We're not saying you must completely cut out meat, because it contains many of the vital nutrients we need to flourish and in a follow up post we will even talk about some potential benefits from regenerative farming that includes livestock. However, by substituting nuts in some meals you can drastically reduce the personal carbon footprint you're responsible for! And when it comes to buying nuts, be sure to find out where they came from and how they are produced.