If Australian livestock numbers increase over the next few years how will this impact emission levels?

If the herd numbers increase, there will be an increase in methane. However, through the industry’s carbon neutral by 2030 (CN30) program of work, we are continuing to develop and implement technologies...

While the amount of methane being emitted by cattle may not change year to year how can that mean that there is no impact on temperatures?

As outlined in the video above not all methane is created equal. Methane generated by ‘life’ is called biogenic methane. One notable source of biogenic methane is ruminants, such as...

How can livestock be a part of the climate solution? Doesn’t methane have more warming power than CO2?

Yes. Using the ‘carbon dioxide equivalent’ (CO2e) metric, methane is commonly referred to as being anywhere from 28 to 100 times more powerful than carbon dioxide, but it is important...

Do cattle emit more GHG than they currently sequester?

In Australia, methane emissions from fossil fuels are rising due to expansion of the natural gas industry, while agriculture emissions are falling. Under a stable livestock population within the red meat...

The carbon cycle explained

Understanding the carbon cycle in livestock farming

Carbon emitted by ruminants like cattle, sheep and goats is recycled into plants and soil, in a process known as the carbon cycle. It's an important natural cycle that's been happening since the beginning of life.

Cows (and other ruminant animals like sheep) are linked to climate change because they emit methane, a strong greenhouse gas (GHG).

The carbon cycle on farm

What is carbon? Carbon is a shape shifter and takes many forms.

It makes up life on earth. It’s stored in trees and soil. It’s also present in gases such as carbon dioxide and methane.

In agriculture, the carbon cycle describes the movement of carbon from the atmosphere, to plants and to animals. But how does it all happen?

Photosynthesis and carbon sequestration

Photosynthesis is an important part of the carbon cycle.

Carbon dioxide in the atmosphere is captured by plants through photosynthesis and turned into carbohydrates (sugars) for plant food. The grazing management of animals supports healthy plant communities on farms.

It’s the process by which plants remove CO₂ from the atmosphere and deposit it into leaves, roots and stems, while releasing oxygen back into the atmosphere. This carbon is then converted into cellulose – an organic compound that’s present in grasses, shrubs and trees. Cows digest the cellulose, turning it into meat, milk and other products. Through digestion and respiration they then breath and burp out CO₂ and CH₄...also known as methane. This returns the carbon to the atmosphere and the cycle continues.

Photosynthesis also facilitates the sequestration of carbon (removal and storage) in soil, large shrubs and trees.

Some carbon is also deposited in the soil through the plant roots and through leaf litter on the surface. Farmers can manage their land in ways to keep more of that good carbon in the system. This helps to maintain healthier soils, increase water retention and plant growth, and support longer term sequestration.

The role of livestock

Cattle, sheep and goats graze the pasture, the carbohydrates break down, and the majority of the plant’s carbon fuels the animal to go about its day. Much of that carbon is deposited as weight gain – so the more healthy pasture and feed, the faster and more efficiently the cattle, sheep and goats can grow.

Some carbon is returned to the atmosphere as carbon dioxide through belching. Some is deposited as fecal matter to the soil, with some respired gases from the manure waste returning to the atmosphere as nitrous oxide and ammonia. If that was all there was to it – the carbon cycle would be in balance.

But what about methane?

Some of the carbon consumed is not turned into carbon dioxide or energy for the animal. Instead it is converted to methane through the process of digestion. Methane, like carbon dioxide, is a greenhouse gas. It is a much shorter-lived gas (approximately 12 years) but it is more potent at warming the atmosphere while it’s there.

The red meat industry is aware of the impact of methane emissions. Our industry faces challenges from increasing climate variability whilst acknowledging the contribution we make to greenhouse gas emissions. As such, the industry has shown global leadership by voluntarily setting a carbon neutral target (CN30) to drive investment into solutions.

The Australian red meat industry is working towards this by reducing methane emissions through innovative technologies and practices, such as improved genetics, new types of livestock feeds and grazing and land management.

The industry is proud to be one of the first industries to set such an ambitious target, and has invested over $140 million into technology and research projects to support it. The Australian Red Meat Industry’s Carbon Neutral by 2030 (CN30) Roadmap pillars set out how the industry will proactively address emissions and become a global leader in sustainable food production.

Diet, genetics and new supplements are being explored to reduce the methane produced by cows, sheep and goats in the natural course of their digestion.

By focusing on environmental management - to produce more feed (grass) and healthier, livestock – the red meat industry can provide more milk, meat and fibre to feed our community from the resources we have. Another way to put this, is that farmers can increase their 'carbon efficiency’ (or emissions intensity) by maximizing product from the least amount resources.

Did you know?

Dung beetles can recycle nutrients in pastures and help store carbon in the soil. Carbon sequestration from these ecosystem engineers could be equivalent to carbon sequestration from 400,000 hectares of eucalypt plantation (source).
Grazing of pastures by livestock helps remove GHG from the air by stimulating more plant growth, turning it into carbon in plants and soil (source).

More about red meat and global warming

Red meat and greenhouse gas emissions

Get the facts on cows, methane, greenhouse gas emissions and climate change.

Red meat and carbon neutrality

The Australian red meat and livestock industry's goal is to be carbon neutral by 2030 (CN30).

FAQs

If Australian livestock numbers increase over the next few years how will this impact emission levels?

If the herd numbers increase, there will be an increase in methane. However, through the industry’s carbon neutral by 2030 (CN30) program of work, we are continuing to develop and implement technologies to reduce methane and increase carbon sequestration to achieve a net zero greenhouse gas position for the red meat industry.

The solution includes increasing the use of natural supplements and additives to reduce emissions, as well as continuing to store carbon in the landscape. With increasing livestock numbers, the industry will continue to increase the rate of adoption of these practices to enable the industry to achieve CN30.
While the amount of methane being emitted by cattle may not change year to year how can that mean that there is no impact on temperatures?

As outlined in the video above not all methane is created equal.

Methane generated by ‘life’ is called biogenic methane. One notable source of biogenic methane is ruminants, such as sheep and cattle.

Biogenic methane is any methane created by things alive today and things that have very recently died. That could be from cows, landfills, or microbes in stagnant ponds. This is a major contributor to the agricultural sector’s climate impact. The creation of biogenic methane is intricately linked to the drawdown of carbon dioxide by photosynthesis.

Simply put, when ruminant animals eat grass, methane is released when they belch, and also from their manure. After 12 years or so, that methane breaks down into ‘natural’ or biogenic CO₂ and water. The grass absorbs the CO₂ through photosynthesis and turns it into carbohydrate. Cows eat the grass, and the whole cycle starts again.

Methane generated by burning fossil fuels is termed ‘fossil methane’ and its impact on our climate is far more destructive.

Fossil methane is made from carbon that has been stored underground for millions of years far from the surface and the global atmosphere. Virtually all gas burned for energy today is fossil methane, and the production of all fossil fuels involves releasing significant amounts of methane. Releasing this methane involves re-introducing old carbon to the active biosphere that had long ago been removed from the system.

Because of the biogenic cycling of carbon, if livestock numbers stay the same, eventually (in about 12 years), the methane produced by livestock will not contribute additional global warming.

In contrast, CO₂ and methane produced from burning fossil fuels, are new to the atmosphere. They do not stem from the natural carbon cycle. New additions of these gases build on what’s already there, day after day, year after year.

Diagram courtesy of the Climate Council Australia.
How can livestock be a part of the climate solution? Doesn’t methane have more warming power than CO2?

Yes. Using the ‘carbon dioxide equivalent’ (CO2e) metric, methane is commonly referred to as being anywhere from 28 to 100 times more powerful than carbon dioxide, but it is important to factor the lifespan of the gases into the equation. When it comes to the difference between methane and carbon dioxide, the most important aspect that is missed by the simple metrics is full consideration of the gases’ different lifespans in the atmosphere. It takes the CO2 released from fossil fuels around 1000 years to be redeposited back into the earth but it only takes methane belched by cattle around 12 years.

Methane is a live-fast, die-young gas. Once released into the atmosphere, methane traps heat much more efficiently than carbon dioxide, but only over the course of around a decade. After this point, it is broken down into carbon dioxide and water, among other things, in a complex set of chemical reactions. Once methane becomes carbon dioxide is remains stable in the atmosphere until it is drawn down.

Carbon dioxide, on the other hand, is a ‘slow and steady’, tortoise-type greenhouse gas. It has a lower potential to heat the atmosphere, but it is a relatively stable gas. This means that unless it is drawn out of the atmosphere through a natural or human process, it continues to heat the atmosphere more-or-less indefinitely. It doesn’t get broken down in the same way that methane is.

Adding carbon dioxide to the active biosphere is a bit like adding water to a sealed water tank. Just like adding water to the tank raises the water level in the tank, so too does adding carbon dioxide to the biosphere. Unless it is removed by some additional means, adding more of both water and carbon dioxide over time results in more being present. This is pretty simple.

Adding methane works differently, it’s a bit more like a tank with an old-slow-to-start, automatic pump attached. This pump tries to remove water at the same rate that it’s added, but takes a long time to start. In the short term, adding more to the tank lifts the level in the tank, but in time – once the pump kicks in – as much is removed as is added. If the rate that water is added remains stable, eventually the amount in the tank will stabilise at a higher level. The breakdown of methane in the atmosphere works in a similar way. Changing the rate that methane is added causes a short-term shift in the amount of methane present, but if the same rate is sustained, then after about a decade the total amount in the atmosphere stabilises as additions are balanced by removals.

Diagram courtesy of the Climate Council.
Do cattle emit more GHG than they currently sequester?

In Australia, methane emissions from fossil fuels are rising due to expansion of the natural gas industry, while agriculture emissions are falling.

Under a stable livestock population within the red meat agricultural sector, there is no additional impact on temperature as emissions would not increase.

Under the Australian red meat industry’s goal to be carbon neutral by 2030 (CN30), carbon neutral means net zero GHG emissions on an annual basis. This means that the amount of GHGs released to the atmosphere by industry is equivalent or less than the amount of additional carbon stored in soils or vegetation in grazing lands in a given reporting year. The sources and sinks of emissions under the CN30 initiative are illustrated below.

According to CSIRO, it is possible to achieve CN30 without reducing livestock numbers below the rolling 10‑year average to 2015 (25 million cattle, 70 million sheep and 0.5 million goats).

The red meat industry is working to reduce emissions through initiatives such as production efficiencies, dietary improvements, renewable energy sources and increase CO₂ stored on farm in the soil and in trees and shrubs.