Beef cattle are also associated with methane production due to their digestive system and this is a significant source of anthropogenic GHG emissions.  

 

Beef production in some forms is associated with a feedback loop that drives land conversion and this has been concentrated in the Amazon region, which is vitally important for climate change management as well as a biodiversity hotspot. Land is cleared for beef production or soy production for livestock feed.  

 

But what we need to remember is that there are a wide variety of beef production systems – and these will have different impacts.   

 

The production system depends on the breed of cow, the time taken to grow the animal, the feed used, and the way the animal is housed.  

 

Livestock include a wide variety of animals like pigs, sheep, goats, but for now let’s focus on beef cows (and so exclude dairy). 

One of the most important aspects of understanding the impact of livestock production is to understand how land use is accounted for in the assessments. 

 

A simple way of looking at land use for livestock is to calculate the area used by the livestock and the amount of time it is used to produce the food being assessed. This helps to compare land use efficiency between different systems – crops vs livestock, for example. 

 

This simple approach misses some key considerations about land use – one called the ‘land opportunity costs’. We should also consider what the land could be used for, so if it was forested land as opposed to agricultural land, what would be the carbon sequestration value of that land? 

 

Again, this also needs to take into account wider issues – what are the rebounds of not using land for grazing, or agricultural production at a global scale? If we reduce agricultural land use in the UK, does this drive land use conversion in other parts of the globe and so continue the environmental impacts of food systems? 

 

Another consideration to make when looking at land use is suitability or productivity of land for agricultural production. Some land is very productive for crop production – a function of the soil type and quality – the amount of water available, whether rain or irrigation, as well as topography, which can have implications in terms of run-off, but also on how easily machinery can be used on the land. 

Some land is more suitable for other uses – grazing, or not suitable at all for agricultural production. In Scotland, for example, there is limited land available which is classed as suitable for the production of crops, whereas the majority of land in Scotland is classified as ‘rough grazing’. This is called ‘Land Capability for Agriculture’, or LCA, classification. 

The analysis looked at the impact from 1kg of beef on:

· Global warming

· Acidification

· Eutrophication

· Land use

· Non-renewable energy use

 

The study found that the impact from dairy cows was lower than for suckler cows. The global warming impact was calculated without taking into consideration land use impacts. 

They calculated the amount of CO₂e (carbon dioxide equivalent) produced per 1kg of meat:

· Suckler cow production systems - 27.3kg 

· Dairy bulls (12 months) – 16kg

· Dairy bulls (16 months) – 17.9kg

· Dairy bulls (24 months) – 19.9kg

 

You can see that the type of production system has a significant impact on the climate change impact, but similar results for other environmental impacts such as eutrophication and acidification were shown. 

 

The study recommends several changes to production that could reduce the environmental impacts of these production systems:

1. Using an optimal diet to reduce enteric methane production (the methane produced as the cow digests food can be reduced by changing the ration)

2. Manure management has a significant impact on reducing the eutrophication and acidification impact from beef production.

 

All four systems rely on off-farm sources of feed – the origin of feed for cows will also be a significant factor in the impact of a production system. 

 

 

There are a number of methods of growing rice, which vary in terms of: 

· Water availability (rain fed or irrigated) 

· The nature of the land (lowland vs upland) 

· The nature of the rice (anaerobic vs aerobic rice) 

 

There are also variations in terms of how the rice is established - in a nursery area (transplanted) or directly sewn into the field (direct seeded).   

There are also a wide range of varieties – such as ones that are fortified (golden rice), organic forms of production as well as the type of inputs used in production such as fertiliser and pesticides used.

 

In countries which produce transplanted rice, it can either be carried out manually (typical in countries with low labour costs such as India and China), or it can be done mechanically. The image here is of rice initially established on mats floating in a nursery pond in Malaysia which are about to be mechanically transplanted for lowland irrigated rice. 

 

As we mentioned, this type of production is a major source of methane and also accounts for a large amount of fertiliser use. It can also have a negative effect on the physical properties of the soil such as impaction. 

 

If this is done manually, the labour rights of workers are also a cause for concern. We will explore labour rights in food systems later in the course.

 

In 2018/19, we produced 732 million tonnes of wheat globally (FAO). This makes wheat one of the top five crops. In the UK, we consume an average of 59kg per person per year. In 2018 China consumed 125 million tonnes, the EU 123 million tonnes and India consumed over 95 million tonnes of wheat.  

 

The biggest producers of wheat are China, India and the USA. Russia and Canada are also key producers.

 

Wheat and rice each provide 19% of calories consumed globally.  

 

The environmental impact of wheat production depends on the type of production system and its efficiency, i.e. the quantity of inputs and the efficiency of the system of production.

 

But here, we are focusing on the impacts of wheat production systems on the environment. Given that it is such a major crop, these impacts are likely to be significant.  

 

Increased yields in wheat from the beginning of the 20th century were driven by access to industrial fertilisers, the breeding of high yield varieties, and the development of a wide variety of pesticides. So, yields went up, and pre-harvest losses went down. This ‘green revolution’ spread across the world, but the increased production slowed towards the end of the 20th century, and concern about the impacts from pesticide use and reliance on industrial fertiliser increased.  

 

In terms of the impacts of wheat production, the most significant will be GHG emissions and water pollution from the application of industrially produced fertiliser – particularly nitrogen. The control of this, as well of the control of the application of pesticides, will depend on where the wheat is grown and the policies applied in that region.

 

Smoke from these fires is blamed for haze (air pollution) events in New Delhi – which have been very disruptive in recent years – and are linked to poor health and even many deaths. The blame for these events has been laid on farmers, but there are many other sources of air pollution in the region. It is undeniable that stubble burning has a significant impact on air quality, however. 

Press play on each audio clip to find out how each food system affects our environment.

You can also select the images to view in full size.