Low Carbon Diet: How to Eat More Sustainably

As climate change becomes a more prevalent part of our lives by the day, many of us are trying to do little things to improve our carbon footprint. But what about what we eat?

Did you know that switching to a low carbon (not low carb!) diet could be one of the more impactful steps anyone can take to help our planet in the long run?

What is a low carbon diet?

The basic answer to this question is a diet that results in lower greenhouse gas emissions and therefore has a low carbon footprint, but how do we go about doing this?

One of the simplest and most effective steps is to reduce meat and dairy consumption. Plant-based diets have been shown to offer a far more sustainable long-term solution for humanity compared to consuming animal-derived products such as meat, eggs, or milk.

However, consumption of animal-based products is just one aspect to consider, as many other factors contribute to a food's overall carbon footprint.

Carbon footprint of food: What is it?

Everyone and everything on this planet has a carbon footprint, which is the amount of carbon emissions produced by an individual, activity, or product.

Plants, unlike meat, require a lot less fossil fuel input to create the final product, and therefore have a far smaller carbon footprint.

For example, research from 2020 showed that creating 100 grams of protein from peas emitted just 0.4 kilograms of carbon dioxide equivalents (kgCO_2-eq), whereas emissions to create the same amount of protein from beef were nearly 90 times higher at 35kgCO_2-eq.

This is because a lot more land, machinery and fertiliser are needed to rear cattle than to grow peas, and the same applies to all animals being farmed compared to most vegetables and fruit.

This isn’t a new concept either; the call for a global shift toward plant-based diets has been around since 2010.

So why does it seem like nothing has changed?

While meat consumption has slightly declined over the past few years, one of the main reasons why we might think little progress has been made is that Western diets tend to primarily revolve around meat and dairy.

This makes a quick transition to a low carbon diet very difficult, not only for the consumers but also for the producers relying on the manufacture of products from animal origin to survive.

We must also consider that a lot of people will be reluctant to change their habits and ways of thinking, especially if they’ve been brought up eating meat and dairy from a young age.

Low carbon foods: Which is the best?

According to research from 2018, nuts and citrus fruit are among the common ingredients with the lowest carbon footprint when it comes to greenhouse gas emissions per kilogram of food product (or kgCO_2-eq) at 0.3.

Wheat and rye produce 1.4kgCO_2-eq compared to rice (4kgCO_2-eq) because flooded rice produces methane, one of the main gases contributing to climate change.

Poultry and pork meat produce the least kgCO_2-eq for land-farmed animals (6 and 7 respectively), as they are non-ruminant livestock, and therefore do not produce methane.

By comparison, lamb and mutton (24kgCO_2-eq) and beef reared for meat (60kgCO_2-eq) have the highest carbon footprint.

This is mostly due to the amount of farming needed to create the final product, as well as the quantity of animal feed required throughout the animal’s life.

10 lowest carbon foods vs 10 highest carbon foods

Does increasing food miles lead to a larger carbon footprint?

While farming and the effects on the land (deforestation, changes in soil carbon, etc) are the main contributors to higher carbon footprints for certain food types, transport also plays a part, albeit very small.

Yes, planes use a lot more fuel than trucks, meaning that importing products that could be grown locally can have a negative impact on the carbon footprint of certain products.

However, seasonality is also key, and there is evidence that trying to grow products locally out of season can produce more greenhouse gas than importing them from a country capable of growing them throughout the year.

For example, a 2009 study found that importing Spanish field-grown lettuce resulted in lower carbon emissions (0.4-0.5kgCO_2-eq) compared to locally grown lettuce in the UK (1.5-3.7kgCO_2-eq). This was because the energy required for heating to grow lettuce locally far exceeded the energy needed for refrigerating the produce during transport from abroad.

Does plastic packaging have the biggest carbon footprint?

Similarly to transportation, packaging, while a contributor, has far less of an impact on climate change and greenhouse gas emissions than the actual production.

That doesn’t mean we shouldn’t consider it when buying our ingredients at the supermarket. After all, buying broccoli wrapped in plastic will be worse for the environment than buying one with no packaging whatsoever.

However, when it comes to packaging with the highest carbon footprint from cradle to grave, glass is the biggest culprit.

While the creation of plastic does produce more greenhouse gas emissions than glass, the weight of the final item created works against the latter.

In fact, research has shown that we need 17-18 times more material for a glass bottle than for its plastic counterpart, which impacts how much fuel is needed to transport it throughout its life, making shipping more expensive and therefore causing more climate damage.

An argument may be made that glass can be infinitely recycled, but this aspect was also taken into account during the research.

Food waste and carbon emissions

It’s estimated that around 6-8% of all human-caused greenhouse gas emissions come from food waste, and cutting this out could have a huge impact on the environment.

This is because most food waste ends up in landfills, which starts rotting and eventually producing methane that ends up in the atmosphere.

That’s why planning ahead and buying only what you need, using your freezer to store food for longer, as well as making the most of leftovers can all help reduce the amount of food that ends up in the bin and landfills.

And if you do end up with food waste, try and ensure it gets properly recycled using a food waste management company.

Low carbon diet: Takeaways

As you can see, having a low carbon diet isn’t just about eating local produce and avoiding plastic products.

There are many factors to consider, but it’s clear that if you want to make a significant environmental impact with your diet, reducing red meat consumption and transitioning to a more plant-based diet would be the most effective approach.

In fact, having one vegan day per week (from a meat-eating diet) can save nearly 143kgs of CO₂ per year, while having one vegan week per month could save as much as 231kgs of CO₂ over the same period!