College of Forestry

Global Trophic Cascades Program

Human Carnivory Project

The human carnivory project emphasizes, in the broadest terms, the effects of humans eating meat on the environment and climate. Illustrated here are the effects of livestock populations on greenhouse gas emissions, biodiversity, riparian ecosystems, and iconic wildlife including wolves, lions, rhinos, and more.

Global Human and Livestock/Methane Counters

The Human Carnivory Project has a youtube channel, check it out!

Recent News

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The Guardian, May 22, 2018: Rangers find 109,217 snares in a single park in Cambodia

The Atlantic, Sept 25, 2017: What If Everyone Ate Beans Instead of Beef?

Would you give up beef if it meant saving the planet?

Australian Popular Science, May 31, 2017: Replacing beef with beans could save the planet, because people farts are better than cow farts  


Hayek M.N., Harwatt H., Ripple W.J., and Mueller N.D. 2021. The carbon opportunity cost of animal-sourced food production on land. Nature Sustainability. 4:21-24.

Wolf, C., W.J. Ripple, M.G. Betts, T. Levi, and C.A. Peres. 2019. Eating plants and planting forests for the climate. Glob Change Biol.

Harwatt, H., W.J. Ripple, A. Chaudhary, M.G. Betts, and M.N. Hayek. 2019. Scientists call for renewed Paris pledges to transform agriculture. The Lancet Planetary Health.

Swain M., Blomqvist L., McNamara J., Ripple W.J. 2017. Reducing the environmental impact of global diets. Science of the Total Environment. 610-611:1207–1209.

Harwatt H., Sabate J., Eshel G., Soret S., Ripple W.J. 2017. Substituting beans for beef as a contribution toward US climate change targets. Climatic Change.

Ripple W.J., Newsome T.M., Wolf C., Dirzo R., Everatt K.T., Galetti M., Hayward M.W., Kerley G.I.H., Levi T., Lindsey P.A. et al. 2015. Collapse of the world's largest herbivores. Science Advances.1(4)

Machovina B., Feeley K.J., Ripple W.J. 2015. Biodiversity conservation: The key is reducing meat consumption. Science of the Total Environment. 536:419-431.

Batchelor J.L., Ripple W.J., Wilson T.M., Painter L.E. 2015. Restoration of Riparian Areas Following the Removal of Cattle in the Northwestern Great Basin. Environmental Management. 55(4):930–942.

Ripple W.J., Smith P., Haberl H., Montzka S.A., McAlpine C., Boucher D.H. 2014. Commentary: Ruminants, climate change and climate policy. Nature Climate Change. 4:2-5.

Ripple W.J., Estes J.A., Beschta R.L., Wilmers C.C., Ritchie E.G., Hebblewhite M., Berger J., Elmhagen B., Letnic M., Nelson M.P et al. 2014. Status and Ecological Effects of the World's Largest Carnivores. Science. 343