It’s nearly Earth Day 2021, and this year’s theme is Restore Our Earth! So let’s have a look at cows and their impact on the environment and what we can do about it. We’ve all heard about how greenhouse gasses are contributing to climate change. We’ve been told the agricultural industry needs to take action and reduce their emissions, but what exactly does that mean?
What are greenhouse gasses?
Greenhouse gasses, simply put, are gasses which absorb and trap heat from the sun when in the atmosphere. They act a bit like the glass windows in a greenhouse. They let light and warmth in and retain that heat, even when it’s much colder outside. Without these greenhouse gasses, we would not be able to survive, as the surface of the Earth would be too cold to sustain life. Greenhouse gasses are constantly produced through natural processes and have been for millions of years.
So what’s the problem?
The problem comes from the fact that, although there are many natural sources of greenhouse gasses, human activity has massively increased the amount of specific gasses that are being released into the atmosphere. As such, we are releasing greenhouse gasses at a greater rate than the environment can remove them. As such, they are building up. This build up increases the greenhouse effect and is what primarily drives global warming and climate change.
Carbon dioxide is famous for its status as the main greenhouse gas we need to reduce. However, there are other gasses that contribute in different and significant ways.
Methane gas consists of relatively small molecules. Wetlands and swamps, rice farming, livestock farming, using natural gas, and coal mining all produce methane in different amounts. The relative impact of methane is large, even though it is released in much smaller quantities than carbon dioxide. Methane is approximately 25 times more powerful than carbon dioxide at warming the Earth over 100 years. The half-life of methane is relatively short – staying in the atmosphere for around 12 years, compared to 200-1000 years for CO2. Reducing our methane emissions is therefore an effective method at mitigating and reducing the effect of global warming.
What does that have to do with cows?
Cows produce a lot of methane gas. Their digestive system releases methane as a by-product of breaking down grass, hay and other plant materials. Over the entire global livestock industry, cattle produce 62% of the sector’s emissions. This is even though there are a little less than half as many cows as sheep and goats, and around 20 times fewer cows than chickens.
How can we reduce greenhouse gasses from cows?
The obvious answer to reducing cow emissions is reducing cow numbers. However, this is not necessarily a feasible strategy. Millions of people depend on cattle as their livelihood and demand for beef and dairy products is only increasing. To reduce cow numbers, but maintain or increase production, each cow must have increased individual gains.
This is happening across the world, as selective breeding, better nutrition, and access to quality health care have increased the yield from individual cows dramatically. For example, in 1970, an average cow in the UK would produce around 4,000 litres of milk over a single year. By 2020, this had increased to 8,144 litres with some cows producing an incredible 12,000 litres of milk in a single lactation. That’s enough milk for over 1.6 million cups of tea, just from one cow!
Many other methods of decreasing methane production in cows are being studied all over the world. From dietary supplements and nutritional changes, to anti-bacterial vaccinations and wearable methane capture units.
Watch this space for a more in-depth look at the specific measures used to decrease methane production in cows and more on the environment and sustainability in the dairy and beef industries.