Livestock, Methane and Climate

TL;DR

This paper argues that livestock methane emissions have a negligible impact on Earth's temperature, with even large reductions resulting in imperceptible temperature changes, highlighting the minimal climate benefit of livestock emission mitigation.

Contribution

It provides a quantitative analysis showing that reducing livestock methane emissions has an almost negligible effect on global temperature, challenging the emphasis on livestock in climate mitigation.

Findings

Killing all cattle in 2025 would reduce temperature by -0.04°C.

Eliminating all sheep would reduce temperature by -0.004°C.

Reducing New Zealand's livestock methane emissions would change temperature by less than 0.00001°C.

Abstract

Methane emissions by livestock have a negligible effect on Earth's temperature. For example, killing all of the approximately 1.6 billion cattle on Earth in the year 2025, when this paper was written, would only reduce atmospheric methane concentrations enough to change the temperature by -0.04 C. Killing all 1.3 billion sheep would lead to a temperature change of -0.004 C. New Zealand's pledge to reduce methane emissions of their livestock by 14% to 24% from those in the year 2017 would change the temperature by -0.000005 to -0.000008 C, far too small to measure. These are maximum temperature savings where methane emissions from domestic livestock are not replaced by other sources (such as wild ruminants and termites) during the inevitable rewilding of managed grasslands and rangelands.