From Nuts to Kelp: The 'Carbon-Negative' Foods That Help Reverse Climate Change

While most food production contributes to climate change by emitting greenhouse gases, a few exceptional foods go a step further—they actively reduce carbon in the atmosphere. Known as "carbon-negative" foods, these items not only have a minimal carbon footprint but also help mitigate the climate crisis by storing carbon or reducing potent greenhouse gases like methane.

Adopting carbon-negative foods could revolutionize how we eat and farm, offering a path toward reversing the impact of our current food systems.

The Carbon Footprint of Food Production

Food production is responsible for 25% of human-caused greenhouse gas emissions. These emissions come from multiple sources, including fuel use by tractors, fertilizer manufacturing, and methane emissions from livestock. However, certain foods have the potential to be carbon-negative when produced using sustainable practices.

Let’s explore some of these foods and how they contribute to a healthier planet.

1. Kelp: The Ocean’s Climate Hero

As kelp and other macroalgae grow, they absorb CO2 from the atmosphere. When parts of the kelp sink to the ocean floor, some of this carbon gets sequestered in deep ocean sediments. Locally-sourced kelp has the potential to be carbon-negative, especially when its supply chain is kept efficient with minimal transport, packaging, and processing.

Moreover, kelp farming can restore damaged marine ecosystems, adding an environmental benefit beyond reducing carbon. While the carbon removal per kilogram of kelp is relatively small, the ripple effects of restoring kelp forests could have a lasting positive impact on the climate.

2. Methane-Oxidizing Bacteria: A New Food Frontier

Methane-oxidizing bacteria consume methane—a greenhouse gas that is 30 times more potent than CO2 over a 100-year timescale. When these bacteria are metabolized by humans, the methane they consume is converted into less harmful CO2.

Innovative products made from these bacteria, such as protein powders or meat substitutes, could soon hit the market. For example, Finnish company Solar Foods launched an ice cream in Singapore in 2023 using a different type of bacteria protein, signaling the potential of this technology.

3. Blueberries, Cranberries, and Celery: Grown on Carbon-Storing Peatlands

Certain crops, like blueberries and cranberries, thrive in wetted peatlands where organic carbon accumulates faster than it decomposes. By farming these foods in carbon-efficient ways, such as minimizing packaging and transport, they can become truly carbon-negative.

However, the availability of such products remains limited, and many fruits, like blueberries imported from Peru, still come with high carbon footprints.

4. Nuts, Olives, and Citrus: Carbon-Storing Cropland Trees

Tree nuts, olives, and citrus fruits contribute to carbon negativity by storing carbon in their trees. When grown on croplands, these trees can remove around 1.3 kg of CO2 per kilogram of product. If managed properly, the carbon stored in trees can remain sequestered for decades, especially when the wood is repurposed into long-lasting products after the trees’ maturity.

5. Regeneratively Farmed Foods: A Soil-Based Solution

Regenerative farming practices, such as no-till farming and planting hedgerows, help store carbon in soil and vegetation. Some companies already claim carbon-negative food production. For instance, British firm Wildfarmed reports carbon removals of 1.5 kg CO2 per kilogram of wheat produced.

That said, regenerative practices have limitations. For high-emission foods like beef, carbon negativity is difficult to achieve, as these practices often require vast amounts of land.

6. Land-Sparing Foods: Maximizing Yields, Minimizing Land Use

One of the most effective ways to make diets carbon-negative is by sparing land for natural reforestation. Switching from high-land-use foods like beef to plant-based alternatives like beans or tofu can free up land for forests to regrow, absorbing significant amounts of CO2.

For example, producing 100 grams of protein from beef requires around 100 square meters of land, while tofu or beans need only 5 square meters. This land-saving strategy could transform our planet, allowing natural ecosystems to flourish while offsetting carbon emissions.

The Role of Carbon Labelling

Identifying carbon-negative foods remains a challenge due to the complexity of supply chains and lack of transparency. However, initiatives like New Zealand's farm emissions reporting and France's planned national rollout of carbon labelling are paving the way. Once robust carbon labelling schemes are in place, consumers will have the tools to make more informed, climate-friendly food choices.

A Vision for a Carbon-Negative Diet

A global shift toward plant-based diets, combined with regenerative farming and carbon-negative food production, could lead to transformative climate benefits. Research shows that if the world stopped consuming animal products and transitioned to plant-based diets, we could return over 3.1 billion hectares of farmland to natural ecosystems. This change could remove 8 billion tonnes of CO2 annually for 100 years—offsetting the emissions of the entire food industry.

Eating for a Better Climate

While achieving a fully carbon-negative diet today requires significant changes in farming practices, consumer habits, and food supply chains, it’s a goal worth pursuing. Incorporating more carbon-negative foods like kelp, nuts, and regeneratively farmed grains into our diets can pave the way for a sustainable future.

With improved labelling, innovative products, and a focus on sustainable farming, we can transform the way we eat to help reverse climate change.