Fueling the fires

California has been in a drought for almost a decade and wildfires are getting worse.  Recent studies using tree ring data shows the current drought were in is the worst one in 1200 years. 

The largest consumer of water in the state, by far, is the animal agriculture sector.  Californians use ~1500 gallons of water per day.  Half of that footprint is due to meat and dairy consumption.   Nearly 1000 gallons of water is required for 1 gallon of cow milk.

Beef and dairy cattle, along with pigs and other farm animals, contribute roughly 27% of methane emissions in the U.S., according to the EPA. Most of that comes from their belching; livestock manure accounts for an additional 10% of methane emissions.

We could effectively cut our water use in half, as a state, if this industry was abolished tomorrow.

DEFORESTATION

By 2050, scientists estimate that an area twice the size of India will be deforested for agricultural purposes. Keeping forests and other ecosystems intact is crucial because they sequester carbon dioxide.

Raising livestock for food takes as much as 36 times more land (than, for example, a comparable amount of peas) because of the space required for grazing animals and the space required to produce feed for those animals.

Animal agriculture is a leading cause of deforestation worldwide and is responsible for 80% of the deforestation of the Amazon in recent years.

Methane

“Limiting warming to 1.5°C implies reaching net zero CO2 emissions globally around 2050 and concurrent deep reductions in emissions of non-CO2 forcers, particularly methane” (high confidence) - UN IPCC Special Report, 2018

Methane is 25-28 times more potent as a greenhouse gas than CO2

• 27% of methane produced is a result of livestock’s natural digestive processes (a process called enteric fermentation)

• Another 9% of methane comes from livestock manure management

• Another 16% of methane comes from landfills when organic matter (usually discarded food) decays without proper composting

highest impact Solutions

The challenge is this: to feed 10 billion people in 2050 without clearing more land for agriculture and while drastically reducing greenhouse gas emissions.

A landmark paper published in Nature in 2018 looked at combinations of changes that could be applied in our food system to keep us within budget for greenhouse gas emissions, including technological changes (increases in productivity through better crop and livestock management, etc.), dietary changes, and reductions in food waste.

They concluded that while a combination of changes are needed, the global shift to a plant-rich diet (see left) is essential and is the highest impact for bringing greenhouse gas emissions from the agricultural sector within budget for 2 degrees of warming or less.

This paper was part of a collection of research by the EAT-Lancet Commission, and its recommendations (now widely cited) became known as the Planetary Health Diet. 14 global cities such Tokyo, Paris, and Los Angeles, have all signed the C40 Good Food Cities Declaration to move their citizens to the Planetary Health Diet.

Read about why healthcare workers and others support San Francisco’s Good Food Purchasing Program

References

1. Ranganathan et. al. (Dec 2019). Creating a Sustainable Food Future. World Resources Institute.

2. Cattle Ranching in the Amazon Region. Yale School of Forestry & Environmental Studies.

3. Livestock’s Long Shadow: Environmental Issues and Options (2006). Food and Agricultural Organization of the United Nations.

4. IPCC Special Report: Global Warming of 1.5°C (2018).

5. Waite and Vennard (Oct 17, 2018). Without Changing Diets, Agriculture Alone Could Produce Enough Emissions to Surpass 1.5°C of Global Warming. World Resources Institute.

6. Springmann, Marco, et al. "Options for keeping the food system within environmental limits." Nature 562.7728 (2018): 519.