'Skip the Steak'

To save the world, we reuse, recycle, take the stairs, switch off the lights. Anyone thought of skipping the steak? Last year, the UNEP Global Environmental Alert Service (GEAS) published a report on ‘Growing greenhouse gas emissions due to meat production’:

In modern societies, industrial-style animal agriculture accounts for 10-35% of global GHG emissions. A typical image conjured is that of Concentrated Animal Feeding Operations (CAFO), where hundreds of thousands of animals are bred in ‘factories’.

Figure 1. Number 45

Source: http://goldilocksfindsmanhattan.com/

Meat Production Problems:

• One of the top three contributors to environmental problems, including deforestation, desertification, and freshwater overuse.
• Animal feed is mainly soya and maize imported from South American countries, which uses intensive fertilizers, leading to land-use problems.
• Cow manure is roughly 3x that of humans: improper disposal leads to runoff and leaching, possibly leading to groundwater contamination.
• Responsible for two-thirds of anthropogenic ammonia emissions, which leads to acid rain and ecosystem acidification.

Most importantly, meat production plays a big role in climate change: enteric (digestive process of livestock) fermentation emits CH₄ (Global-warming potential 25 compared to CO₂’s GWP 1), and excreted nitrogen and N fertilizers release N₂O (GWP 296). Deforestation and grassland conversion into agricultural land causes soil to decompose C-rich humus, releasing CO₂ and N₂O into the atmosphere.

In beef production, 16 kg CO₂/ kg beef is emitted compared to 2.5 kg CO₂ for pork and 0.8 for wheat. Beef is the least efficient way to produce protein, even less than vegetables with a low protein content, such as carrots and green beans. In GHG terms, consuming 1 kg of beef is equivalent to running a car for 160 km.

USA leads the world in beef consumption with 322g/person/day, which is roughly equal to THREE hamburgers. However, Asia holds the fastest growth in meat consumption due to increasing income and population growth.

 Figure 2. Meat supply in kg/capita/year

Source: UNEP

The planet needs sustainable food systems. Carbon sequestration will help mitigate GHG releases, but it holds high implementation costs. Industrial farmers must aim to improve feedstock efficiency, diets, and manure management.

Environmentalists are urging people to reduce red-meat consumption or switch to plant-origin protein substitutes. Switching to more ‘environmental-friendly’ meats such as pork and poultry will also reduce GHG emissions.

Figure 3. Production emissions of different products

Source: Environmental Working Group

Here’s a £200,000 test-tube burger grown from stem cells. Careful! It’s not as juicy.

References:

"Growing greenhouse gas emissions due to meat production." UNEP Global Environmental Alert Service. UNEP. 

This blog post owes its name to Time's Global Warming Survival Guide.