Compare Protein Sources
Select any two protein sources and compare their CO₂ emissions on an equal-protein basis. Adjust the protein target to see how emissions scale with portion size.
96g
240 kcal
500g
405 kcal
For 25g of protein, Beef produces 88× the CO₂e of Peas
Difference: 8.7 kg CO₂e
If Peas is like driving 1 Prius, then Beef is like driving:
Peas
1 Prius
Beef
10 Semi-Trucks
at the same time
That's 87.5× the climate impact
Data based on global averages from Poore & Nemecek (2018). Actual emissions vary significantly by producer, region, and production method. Ranges shown represent 10th–90th percentile estimates.
Understanding the Data
All emissions data is expressed as kg CO₂e per 100g of protein, allowing fair comparison across foods with different protein densities.
The ranges (low to high) represent the 10th to 90th percentile of global production, reflecting variation by producer, region, and farming practices.
Beef shows particularly high variation due to differences in land use change, feed systems, and whether cattle are from beef herds or dairy herds.
Why Compare on Equal Protein?
Protein is an essential macronutrient, and comparing foods on an equal-protein basis shows the true cost of meeting your protein needs from different sources.
A typical adult needs about 50-60g of protein per day. The default 25g comparison represents roughly one meal's worth of protein.