Climate change refers to the long-term shift in the Earth’s average weather patterns that have come to define global climates. These changes to the Earth’s climate are primarily being driven by human activity, increasing heat trapping gases in the Earth’s atmosphere, and in turn increasing the Earth’s overall average surface temperature [ref].

The effects of this will see global temperatures continue to rise, extreme weather events, food supply disruptions, increased drought and wildfires [ref]. It is important that we understand the role we as humans play in the changing climate, and what it can mean for the future of the living world [ref].

So what does climate change have to do with the animals we raise for food and fibre?

Animal agriculture is a huge emitter of greenhouse gases (GHG), accounting for 14.5% of total global emissions [ref]. GHG are heat trapping gases that accumulate in the atmosphere, warming the planet and in turn driving climate change. 

Deforestation

Animal agriculture is a huge cause of deforestation, both to make way for grazing pasture and to grow crops fed to livestock. Upwards of 70 billion animals are raised for human consumption each year. Unsurprisingly, these animals consume a considerable amount of feed, namely soy and cereals. As the world’s consumption of meat continues to rise, so too will the land required for growing feed. 

So what does deforestation have to do with climate change?

Forests are carbon sinks; trees play a vital role in storing carbon dioxide (CO2) gas, keeping them from accumulating in the atmosphere and warming the planet. When trees are cleared, the CO2 they had stored is released into the atmosphere. Further, those trees will no longer collect and store CO2, so not only does deforestation emit greenhouse gas emissions, it removes a crucial natural ally that acts to reduce climate change by storing GHG emissions [ref].

Other carbon dioxide emissions

Carbon dioxide is considered to be the most powerful greenhouse gas emission due to the sheer volume of its emissions. Aside from deforestation, the animal agriculture sector produces carbon dioxide in a number of ways [ref]:

  1. Chemical fertilisers, used to grow feed crops, require a vast amount of CO2 emissions in order to be produced each year.
  2. Cultivation for feed crops also produces CO2. Like forests, soils are also carbon sinks, and cultivating the ground for animal feed crops releases CO2.
  3. Powering factory-farms requires a huge amount of fossil fuel-based energy, which emits vast amounts of CO2, for heating and cooling, ventilation systems, and operating farming machinery.
  4. The slaughtering and processing of animals’ bodies, as well as distribution of end products, emits CO2 emissions.
  5. The grazing of animals on land can cause soil that was once fertile to dry out and release millions of tonnes of CO2 into the atmosphere every year. This is known as desertification.

Methane

Methane is a greenhouse gas emission that is approximately 30 times more potent than carbon dioxide as a heat trapping gas over a 100 year period [ref]. This means that, in terms of global warming potential, one tonne of methane is roughly equal to 30 tonnes of CO2.

The manure of ruminant animals, particularly cattle, produces methane. According to the Environmental Protection Agency, just one ‘dairy’ cow will produce 18 tonnes of manure annually [ref].

When comparing the impact of beef and tofu it becomes clear just how harmful beef production can be in terms of global warming potential. Producing just 100 grams of beef emits on average 50KG of greenhouse gas emissions, whereas the same amount of tofu emits approximately 2KG of greenhouse gas emissions [ref].

Despite being much more impactful than CO2, methane breaks down in the atmosphere quicker. In the global climate crisis we are currently facing, time is everything, and eliminating the greenhouse gas emissions produced by ruminant animals is essential to rapidly halting rising global temperatures.

Nitrous Oxide 

Nitrous oxide is a greenhouse gas emission that has nearly 300 times the global warming potential of CO2. Global animal farming, including the production of feed crops, is responsible for 65% of global nitrous oxide, which can remain in the atmosphere for up to 150 years [ref].

https://www.intechopen.com/books/animal-husbandry-and-nutrition/nitrogen-emissions-and-mitigation-strategies-in-chicken-production