Food Sustainability Beyond CO₂: Why Carbon Footprint Isn't Enough

At a glance

The bottom line: CO₂ matters, but it doesn't define food sustainability on its own.

Key insights:

- Rice uses 14x more water than pasta despite identical CO₂e emissions

- Hazelnuts require 50% more land than peanuts with comparable climate impact

- Multi-indicator assessment prevents greenwashing and reveals true hotspots

In this article: What food sustainability means beyond carbon, why looking at water and land data changes the story, and how to apply this in professional kitchens.

What do we mean by "food sustainability"?

Food sustainability refers to the total environmental impact of food across its life cycle — from agricultural production to processing, transport, and consumption. In Europe, this is assessed using Life Cycle Assessment (LCA) and databases like Agribalyse (French national database developed by ADEME), which measure:

• Climate change (CO₂e): greenhouse gas emissions

• Water use (m³): freshwater consumption

• Land use (Pt): land occupation impact

• Eutrophication: nutrient pollution

• Biodiversity pressure: habitat conversion

  
  

No single indicator captures all impacts.

Why CO₂e is used and why it's not enough

CO₂e (carbon dioxide equivalent) expresses climate impact by converting all greenhouse gases to CO₂ equivalents. This works because different gases have different warming potentials. For instance, methane causes over 80 times more warming than CO₂ on a 20-year timescale (IPCC AR6).

But CO₂e does not measure water scarcity, land occupation, nutrient pollution, or biodiversity pressure. That's the gap.

The risk of carbon tunnel vision

When sustainability is reduced to CO₂ alone, we create carbon tunnel vision: choices that look good for climate but shift environmental pressure elsewhere.

Rice vs pasta: identical CO₂e, 14x different water use

According to Agribalyse data:

Product	CO₂e (kg/kg)	Water use (m³/kg)
Rice	2.00	14.3
Pasta	1.98	0.984

From a climate perspective, rice and pasta are virtually identical.

From a water perspective, rice uses over 14 times more water per kilogram.

Why this difference exists

Rice grows in flooded paddy systems requiring 1,500-3,000 liters of water per kilogram. Pasta comes from wheat, which in European contexts is largely rain-fed, requiring only 500-1,000 liters per kilogram. Same CO₂e. Completely different water story! This matters critically in water-scarce regions like Southern Europe.

Hazelnuts vs peanuts: similar CO₂e, 50% more land

Agribalyse data shows:

Product	CO₂e (kg/kg)	Land use (Pt/kg)
Hazelnuts	4.81	819
Peanuts	4.18	535

Climate impact is comparable, but hazelnuts require over 50% more land per kilogram.

Why land use differs

Hazelnuts grow on perennial trees with lower yields per hectare (1-2 tonnes/ha). Peanuts are annual crops with higher yields (2-4 tonnes/ha) and better land-use efficiency. Land use links directly to deforestation, habitat loss, and biodiversity pressure.

Real-world example: scaling the impact

Scenario: Corporate catering serving 500 portions daily, 5 days/week

Current: Rice pilaf served 1x weekly (100 kg rice per service)

Change: Replace 1 rice dish in 2 weeks with pasta

Annual water savings:

• Rice: 14.3 m³/kg × 100 kg × 25 weeks (biweekly) = 35,750 m³

• Pasta: 0.984 m³/kg × 100 kg × 25 weeks (biweekly) = 2,460 m³

• Net saving: 33,290 m³/year (13 Olympic pools)

Climate impact: Unchanged (<1% difference)

Conclusion of this example: By diversifying with pasta, 33,290 m³ water can be saved annually while maintaining nutritional quality, with neutral climate impact.

Why this matters for food service

Looking beyond CO₂e helps you:

• Avoid greenwashing: sustainability isn't one number

• Identify real hotspots: water or land may be your critical factor

• Make smarter swaps: reduce multiple impacts simultaneously

• Align with EU regulations: CSRD expects multi-indicator reporting

• Communicate with confidence: backed by transparent LCA data

At scale, these differences compound rapidly.

From complexity to clarity

Sustainable food decisions don't require more data, they require better interpretation.

CO₂e is essential for climate assessment, but better decisions begin when we look beyond carbon and act on what we find.

Frequently Asked Questions

Why is CO₂e not enough?

It measures only climate impact, missing water consumption, land occupation, pollution, and biodiversity pressures.

Which uses more water: rice or pasta?

Rice uses approximately 14x more water (14.3 m³/kg vs 0.984 m³/kg) because it's grown in flooded systems, while wheat is largely rain-fed.

How can I track multi-indicator sustainability?

Use LCA databases like Agribalyse (free) or request Environmental Product Declarations from suppliers. Start with high-volume ingredients.

Does this cost more?

Not necessarily. Many lower-impact swaps like pasta for rice are cost-neutral or cost-saving.

Sources

1. IPCC Sixth Assessment Report (AR6), 2021 — Climate science and GWP values

2. Poore & Nemecek (2018), Science — Meta-analysis of food environmental impacts

3. Sei (2022) - It's Time To Move Beyond Carbon Tunnel Vision

4. Mekonnen & Hoekstra (2011), UNESCO-IHE — Water footprint database

5. Agribalyse v3.2, ADEME — French LCA database for food

6. Water Footprint Network — Methodology and data