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Can changing your diet really help combat the climate crisis?

Author: Katy Baker

Simply said, the answer is yes. The way that we feed Earth’s population today is unsustainable for the future. Earth’s overshoot day, the day where more natural resources have been used than can be renewed in the year, is moving increasingly forward each year. We have an infinite demand for natural resources, yet a finite supply.

We have terrifically changed the biosphere of our Earth.; the weight of all livestock on Earth accounts for 67% of all land mammals, with 7.8 billion humans weighing 30% and wild animals at only 3%. Nearly 40% of land area on Earth is occupied for agriculture, where two thirds of this is made up of pastures for livestock.

Total food emissions are accountable for 37% of global greenhouse gas (GHG) emissions; we need to feed our planet, but how to do this sustainably is in question. Food production and emissions are entangled in a vicious cycle; the more emissions we create, from food production and other sources, the higher the uncertainty of global food security in the future. One study stresses that if emissions continue to rise “business as usual”, one third of food production will be pushed beyond safe climatic space.

Animal-based vs plant-based

What we choose to eat determines how much we contribute to the warming of the Earth. Animal agriculture generates 7.1 gigatons of CO₂-equivalent per year, and accounts for 14.5% of all anthropogenic GHG emissions, according to the FAO. Cattle raised for beef and milk are accountable for the highest proportion of the livestock sector emissions. Animal agriculture is responsible for an estimated 18% of all GHG emissions, higher than total emissions from the global transport sector.

Animal agriculture is the main driver of 80% of deforestation in the Amazon rainforest. In tropical rainforests, trees are deforested for land use change (LUC) for both transformation into pasture-land and agricultural land used to feed livestock, removing ancient carbon sinks and disrupting ecosystems. Soybeans are the main feed for cattle and Over 96% of Amazon-grown soy is given to cows, pigs and chickens as feed. Conversely, only a meagre 6% of world soy consumption is human.

Beef is one of the most resource intensive yet inefficient sources of protein. The production of 1kg of beef requires 20kg of feed, 50,000 litres of water (compare this to only 1,010 litres for 1kg of wheat and 2,200 litres for soybeans, estimated by research body CSIRO). Animal agriculture uses almost 100 times more land to produce one gram of beef than a plant-based alternative such as tofu or peas. The production of one kilogram of beef emits 60 kilograms of GHGs, whilst one kilogram of peas emits just one kilogram of GHGs. Animal agriculture emissions not only comprise of high CO₂ concentrations but also methane in the case of cattle and other ruminants, where methane has a global warming potential of up to 86 times that of CO₂, on a 20-year time frame.

Studies show that a western meat-based diet produces 7.2kg CO₂-e a day whereas a vegan diet only produces 2.9 kg CO₂-e. Additionally, the Committee on Climate Change shared that a plant-based diet could reduce individual dietary emissions by 35%. A recent study states the potential for sequestration of 332-574 gigatons of carbon dioxide by a global shift to a 70% plant-based diet. This would be equivalent to 99-163% of our carbon emissions budget coherent with a 55% chance of limiting warming to 1.5 degrees Celsius. Similar findings from WWF investigated the potential carbon storage and climate change mitigation potential cutting out animal products from our diets had, including afforestation potential with decreased demand for pasture driven LUC.

Is going vegan viable for everybody?

As global population levels continue to rise to an estimated 9.8 billion by 2050, analogously so will the demand for meat. As income levels and national GDPs rise over the next 10 years, the OECD/FAO (2021) predicts a rise in meat consumption by 12% coupled with a 50% rise in food related GHG emissions, and a 50-90% rise in environmental impact, described by researchers as “reaching levels that are beyond the planetary boundaries that define a safe operating space for humanity”.

Changing your diet to a vegan or plant-based diet has huge benefits to the planet and reduces your carbon footprint and demand for natural capital. But is it a viable option for everyone? The answer is no. One billion people, predominantly in Asia, rely on fish as their primary source of animal protein. The commitment to a plant-based diet and veganism cannot be expected on those who do not have a choice on what to eat; responsibility must fall on those who are not only culpable, but who also have the financial and resource ability to make a greener choice as consumers. Diets of Western Europe and USA consume twice the amount of daily protein intake recommended by the WHO. As consumers, we have a lot of influence in how we choose to use our consumerist powers. But a point to note, individualistic action mitigating climate change cannot solely be a solution. Collective action by stakeholders at local, regional, and global levels is required for widespread and effective climate action.

Concluding remarks...

Plant-based diets not only shift the demand for meat production and reduce emissions but are a nature-based solution to rebuilding ecosystems, investing into more sustainable agriculture, and closing the gap on hunger inequality. Intersectional veganism understands the gravity of climate injustice and inequality of how we consume as a global population. We need great structural change in society to combat the climate crisis, like we did during the COVID-19 pandemic, through both individual and collective action. Eating sustainably can be seen as a spectrum, it doesn’t have to be polarised; changing your diet to a more planet-based diet is one of the individualistic climate actions that we take as consumer capitalists in the Global North with the ambition of keeping global warming below 2°C.


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