The impact of cow methane on climate change

Planet boundaries for phosphorus and biodiversity are at risk. They are the 2 the planet boundaries for which we are beyond the zone of uncertainty. For greenhouse gas emissions we are still in the zone of uncertainty, which means we need to intensify our efforts to achieve reductions of cow methane emissions (see Figure 1).

The Global Methane Pledge has been signed by over 150 countries. The goal that has been agreed is to reach climate neutrality by 2050. To reach this goal, a reduction of greenhouse gas emissions of 50% by 2030 is required, followed by an annual reduction of 1%. Of all greenhouse gasses, methane is the most relevant target. The effect of reduction of methane will however be partly offset if we don’t reduce nitrous oxide at the same time (see figure 2).

Methane from cows contributes significantly to greenhouse gas emissions and climate change. Estimates vary between sources, but according to FAO¹, 14.5% of global greenhouse gas emission is related to farming (see Figure 3). In the US, livestock, including cattle, are responsible for about 35% of anthropogenic methane emissions in the US. 

The greenhouse gas effect of cow methane is 27 times bigger than the greenhouse gas effect of carbon dioxide. Therefore, methane from cows, despite being emitted in smaller quantities compared to carbon dioxide, has a more potent warming effect. For this reason, it is crucial to address cattle methane emissions to combat climate change effectively. This article will explore the sources of methane emissions from cows, the impact on the climate, and strategies for reducing cow methane emissions.

How do cows produce methane? Methane emissions from cows primarily originate from two sources: enteric cow methane emissions and cow methane emissions from manure. The anaerobic conditions in manure lagoons and manure pits contribute to the release of methane gas from cows. In beef cattle, cow methane emissions are mainly from enteric fermentation. In dairy, cow methane emissions are more equally split between enteric fermentation and manure management practices (see Figure 4).

The exact split of methane production in cows between emission of cow methane from enteric fermentation and methane from cows coming from manure is depending on diet, production level and production stage. The actual split of cow methane between enteric fermentation and cow methane emission from manure may therefore differ between sources.

Cow methane, although emitted in smaller quantities, has a stronger warming effect compared to carbon dioxide. Over the past 100 years, carbon dioxide has caused the highest warming effect, followed by methane and nitrous oxide. Despite methane's shorter lifespan in the atmosphere, its radiative forcing capability makes efforts to reduce cow methane crucial. The reduction of methane gas from cows has the potential to significantly contribute to achieving the goals for 2050, outlined in the Paris Agreement.

Improving feed efficiency to reduce methane from cows:
If feed efficiency is increased, more milk will be produced out of the same amount of feed. This also means that the amount of cow methane per kg of ECM produced on the farm will go down. Selko IntelliBond is an example of a feed additive that improves feed efficiency and as a result, it reduces the amount of methane gas from cows per kg of ECM by 1.5-2%.

Increasing Lifetime Daily Yield to reduce cow methane
Lifetime Daily Yield (LDY) can be increased by improving calf rearing practices and transition management. If LDY goes up, the amount of methane produced during the rearing phase and also, the amount of methane produced for maintenance will be diluted over more kg of ECM, resulting in a redcution of cow methane emission per kg of ECM produced.

More about Lifetime Daily Yield >

Improving Feed Management to reduce methane from cows:
Modifying the diet of cows can help reduce enteric fermentation and, consequently, cow methane emissions. There are also feed additives such as Selko Fytera Balance that can lower enteric cow methane production by 5-6%. Next to the direct effect of Selko Fytera balance on cow methane emissions, there is also an indirect effect, resulting in another 2-3% reduction of methane from cows. 

Improving Manure Management to reduce cow methane:
Implementing anaerobic digestion systems or capturing cow methane from manure lagoons can effectively reduce cattle methane emissions. These systems convert the captured cow methane into biogas, which can be used for energy production.

Genetic Selection to reduce methane from cows:
Identifying and breeding cows with lower cow methane production potential can contribute to long-term reductions of emission of methane from cows.

Methane-Capturing Technologies to reduce cow methane:
Technologies like methane-capturing backpacks or masks can be used on cows to collect and measure cow methane emissions accurately. This data can aid in identifying cows with high emission levels of cow methane. These data can also be used for developing targeted cow methane mitigation strategies.

Improved Grazing Practices:
Implementing rotational grazing techniques and pasture management strategies can help shifting the rumen fermentation in a way that less methane is produced during fermentation.

Nutrient Management:
Optimizing the use of nitrogen-rich fertilizers and implementing precision farming practices can reduce nitrogen-related emissions, including emission of nitrous oxide which is also an important greenhouse gas of cows next to methane from cows.

Through a combination of increasing feed efficiency, improved feed management, manure management practices, genetic selection and the adoption of innovative technologies, the dairy industry can contribute significantly to reducing cow methane. By implementing these strategies for reduction of methane from cows, we can take a significant step towards achieving a more sustainable future with lower cow greenhouse gas emissions.