Eating foods with low carbon footprints can help reduce emissions, but there exist specific foods that not only reduce emissions but actively absorb carbon from the atmosphere, contributing positively to climate sustainability.

We are well aware that the production of most foods generates greenhouse gas emissions, a significant driver of climate change.

These emissions stem from various sources, such as fuel-burning tractors, fertilizer manufacturing, and methane produced in livestock. In total, the production of food accounts for a quarter of human-caused greenhouse gas emissions.

Nevertheless, there are some exceptional foods that excel in removing more greenhouse gases than they emit, commonly known as "carbon-negative" foods. These food items leave the climate in an improved state compared to before. By producing and consuming more of these foods, we could potentially reduce the carbon impact of our diets and even aid in ecosystem restoration.

Kelp

Kelp and other macroalgae absorb carbon dioxide (CO2) as they grow. Portions of kelp that break off sink to the deep ocean floor, where some of the captured carbon gets stored. Although the carbon removal per kilogram of kelp is minimal, for kelp-based foods to be carbon negative, the entire supply chain must be highly efficient in carbon reduction, including minimal transportation, packaging, and processing.

Kelp sourced locally holds promise for being carbon negative, although this remains a minority scenario today. Supporting the purchase of kelp could serve as an incentive to restore vast kelp forests that have suffered destruction—a positive environmental impact that stretches beyond climate change mitigation.

Bacterial Products

Methane-oxidizing bacteria found in various environments consume methane for energy. This consumption is beneficial as methane is a potent greenhouse gas, contributing significantly to global warming compared to CO2.

Consuming products containing these bacteria can convert methane into a less impactful greenhouse gas, CO2. Research indicates that these bacteria can utilize nutrient-rich waste streams, like food waste or animal manure, as a nutrient source. Although bacterial products such as protein powders or meat alternatives are likely carbon-negative, they are not widely available in stores yet.

Blueberries and Celery

Organic carbon can accumulate in wetted peatlands faster than it decomposes. A select few products, including blueberries, cranberries, and celery, can be cultivated in wetted peatlands, offering the potential for carbon negativity if the supply chains are optimized for minimal carbon impact.

Fresh blueberries, often packaged in plastic and transported globally, currently have a high carbon footprint, but carbon-negative products from peatlands are rare. Yet, this emerging area is worth monitoring for future developments.

Nuts, Olives, and Citrus

Planting trees on cropland aids in carbon storage. The global tree nut area has doubled over the last two decades, especially on croplands. Even after considering the full supply chain, a typical nut product today effectively removes approximately 1.3kg of CO2 per kilogram until the trees mature, typically after 20 years. Utilizing these trees for long-lasting wood products can further store carbon for extended periods.

Regeneratively Farmed Food

Numerous regenerative practices, like avoiding soil tilling or planting hedgerows, can enhance carbon storage in soil or vegetation. Some companies with efficient supply chains assert they have achieved carbon negativity. While regenerative practices show promise, certain high-emission foods may not be candidates for carbon negativity through these methods due to potential offsetting emissions.

Efforts are underway to implement carbon monitoring and labeling schemes globally, enabling consumers to identify carbon-negative foods easily. As these initiatives gain regulatory support, the identification of carbon-negative foods should become more accessible to everyone.

Land-Sparing Foods

While carbon-negative foods hold potential, they may only constitute a small fraction of diets due to limited availability. Therefore, strategies beyond carbon-negative foods are essential. Land sparing, achieved by boosting yields or switching to products that use less land, can indirectly lead to carbon negativity by allowing reforestation and increased carbon absorption.

Shifting away from land-intensive products, notably meat and dairy, to land-efficient alternatives like plant-based foods can be a highly effective method for attaining carbon-negative diets and fostering sustainability on a broader scale.