Does transport emit more than cows?

Transport and livestock emit about the same, but food as a whole emits roughly twice as much as transport. The UN climate panel IPCC finds that transport caused 15 percent of the world's greenhouse gas emissions in 20191. The UN's Food and Agriculture Organization (FAO) estimates that livestock caused about 12 percent in 2015, with cattle responsible for roughly 62 percent of that2. The two aren't counted the same way: FAO's figure covers livestock's whole chain, from the farm and land clearing to processing3.

The whole food system, from field and barn through processing and transport to waste, caused 31 percent of the world's emissions in 2018 according to the IPCC, with a range of 23 to 42 percent4. A global study finds that animal foods, including their feed, cause 58 percent of food emissions, and plant foods 29 percent5. That is why figures above 50 percent come up so often: they are livestock's share of food emissions, not of all emissions.

These figures only show what is emitted today, not what the land could store if it weren't used for animals. When a diet with less meat frees up farmland, new vegetation on that land can take up carbon, the IPCC writes6. The CO2 that nature could take up on the land livestock use today is of the same order of magnitude as the past decade of fossil fuel emissions worldwide7. For Denmark, the US think tank World Resources Institute estimates that farming's use of land costs about 48 million tonnes of CO2 a year in lost carbon storage8, 12 million tonnes of it on land abroad growing imported feed. That is almost three times farming's yearly emissions from production itself9. None of this is counted when livestock is compared with transport.

In Denmark, farming and forestry are projected to emit 12.4 million tonnes of CO2e in 2030, against 9.6 million tonnes from road transport10. Animal production is expected to cause 52 percent of farming and forestry emissions11, so a little less than road transport. Both figures are projections from a government-appointed expert group on green tax reform.