Short- and long-term warming effects of methane may affect the cost-effectiveness of mitigation policies and benefits of low-meat diets

Ignacio Pérez-Domínguez,Guillermo Pardo,Stefan Frank,John Lynch,Petr Havlik,Hans Van Meijl,Jordan Hristov,Peter Witzke,Klaus Mittenzwei,Jason F L Koopman,Agustin Del Prado,Jesus Barreiro-Hurle,María José Sanz-Sánchez,Andrzej Tabeau,Elke Stehfest

doi:10.1038/s43016-021-00385-8

Abstract

Methane’s short atmospheric life has important implications for the design of global climate change mitigation policies in agriculture. Three different agricultural economic models are used to explore how short- and long-term warming effects of methane can affect the cost-effectiveness of mitigation policies and dietary transitions. Results show that the choice of a particular metric for methane’s warming potential is key to determine optimal mitigation options, with metrics based on shorter-term impacts leading to greater overall emission reduction. Also, the promotion of low-meat diets is more effective at reducing greenhouse gas emissions compared to carbon pricing when mitigation policies are based on metrics that reflect methane’s long-term behaviour. A combination of stringent mitigation measures and dietary changes could achieve substantial emission reduction levels, helping reverse the contribution of agriculture to global warming.

Highlights

Methane’s short atmospheric life has important implications for the design of global climate change mitigation policies in agriculture
The transiency of CH4 emissions is key for determining cost-effective climate change mitigation options in the agricultural sector and assessing their impact in a rigorous manner
We show how different valuations of CH4 relative to CO2 impact the choice of mitigation policies in agriculture and, affect the sector’s contribution to further global warming

Summary

Result indicator

No carbon pricing MEF-LT (= 6.25) GWP100 (= 25) MEF-ST (= 100) No carbon pricing MEF-LT (= 6.25) GWP100 (= 25) MEF-ST (= 100) No carbon pricing. Overall production decreases 4% under a carbon pricing regime based on the short-term warming impact of CH4, while the reduction is 2–3% under a GWP100 pricing regime with a carbon price of US$150 t−1. While global livestock per-capita calorie consumption is reduced in the dietary shift scenarios by about 4–18% in 2030, 13–31% in 2050 and 23–36% in 2070, depending on the model, the reduction is much lower when only considering carbon pricing (around 9% achieved by the CP500_ST scenario). This calorie reduction takes place only in emerging economies with high meat consumption (for example, China, former Soviet Union, Brazil) a Articles b. Developed countries (European Union, United States, Canada, Australia and New Zealand)

Discussion

Findings

Methods