Wheat: Emissions
The footprint of a loaf, from farm to shop
What this tab covers The greenhouse-gas footprint of the commodity at a global level, split by lifecycle phase: extraction (or farming), refining and processing, movement, usage, and recycling or end of life. Intensities are per unit of product; the global total combines intensity with world output. Also covers other environmental impacts and the main levers to cut emissions. Emission intensity 1.57 kg CO2e per kg range wide by farm and region · cradle-to-retail, global mean of 2010 data for wheat and rye; phase shares not shown here, but the farm stage is largest Global emissions per year 1,300 Mt CO2e per year 2025/26 · 1.57 kg/kg times 844 Mt; an upper bound, since grain at the farm gate skips baking, packaging and retailPer kg of wheat product (bread), cradle-to-retail including land-use change, global mean. Intensity: Poore and Nemecek (2018), Science, via Our World in Data. Global total: Derived from Poore and Nemecek (2018) and USDA (indicative).
Footprint by lifecycle phase
| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| Extraction | N-fertiliser supply chain alone about 0.25 t CO2e per t grain (derived) | – | N fertiliser manufacture and field N2O, diesel, irrigation pumping | Derived: wheat takes about 18% of world N fertiliser (Heffer et al. 2017, indicative), about 24 kg N per t, times 10.5 t CO2e per t N | Menegat et al. (2022); IFA (indicative) |
| Refining / processing | milling about 0.03-0.07 t CO2/t at Indian grid intensity (indicative) | – | roller-mill and chakki electricity of roughly 50-100 kWh per t; baking ovens add more for bread | India's grid is about 0.7 t CO2 per MWh (CEA CO2 Baseline Database, indicative) | CEA (indicative) |
| Movement | about 0.01-0.1 t CO2/t (indicative) | – | rail and bulk shipping; bulk carriers emit roughly 3-10 g CO2 per tonne-km depending on size (IMO Fourth GHG Study 2020, indicative) | Black Sea to Egypt is short; Australia or Canada to Asia is long | IMO Fourth GHG Study 2020 (indicative) |
| Usage | cooking fuel for roti and bread; about 20.5% of wheat is fed to animals | – | LPG, biomass or electric ovens | feed share from USDA 2025/26 | USDA WASDE (Oct 2026) |
| Recycling / end of life | losses and waste carry the full footprint without use | – | storage losses, bread waste | Food loss and waste is about 8-10% of global GHG emissions (UNEP Food Waste Index 2024, indicative) | UNEP (2024) (indicative) |
Other environmental impacts
Irrigated wheat in north India and the North China Plain depletes groundwater. Straw burning in Punjab adds to winter air pollution, though rice stubble is the larger source. Heat during grain fill is cutting yields.
Levers to cut emissions
- Better N timing and placement, and less urea per tonne (Menegat et al. 2022)
- Zero tillage and residue retention instead of burning
- Solar irrigation pumps in India
- Cut storage losses with sealed silos and better PDS handling
India
India produced about 14% of world wheat and was 14.7% of world fertiliser-N emissions (Menegat et al. 2022), with heavy urea use and electricity for tubewells on a coal-based grid raising farm-stage emissions (FAOSTAT; CEA, indicative).
Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.