Carbon emissions of food production

How big is the impact of farming methods on our carbon footprint?
05 June 2018

Interview with 

Joseph Poore, University of Oxford


A cow


One of the biggest drivers of carbon emissions and land use around the world is food production, with beef having a larger carbon footprint than other meats, and meats being worse for the planet than vegetables. A new study from Oxford has suggested that there is variation within products depending on suppliers and methods used. Georgia Mills spoke with Joseph Poore about what this could mean for reducing our carbon footprint...

Joseph - The initial inspiration was I wanted to understand if I could reconcile my personal consumption of animal products with a rapidly degrading global environment. I wanted to know if there are farmers out there who are producing low environmental impact foods, and if so, what could we learn from them.

Georgia - So we already knew that some products were worse for the environment than others. But you wanted to go one step further and find out within each range what was going on?

Joseph - Yeah that's right. So we wanted to see the range of impact between low impact producers and high impact producers with the same product, not just on greenhouse gas emissions but on land use, water use, acidification, eutrophication, other important environmental indicators. We also wanted to do this for the whole food supply chain. So from the clearing of land to agriculture, the production of fertilizer, right through to transport and retail.

Georgia - Right. So how did you get ahold of this data?

Joseph - We used data from 720 published studies and these studies have visited farmers and other companies in the food supply chain in countries all around the world. We brought this data together and consolidated data on 40 thousand farms and 16 hundred processors, packages and retailers.

Georgia - When you picked this data then what did you find? What were the big surprises?

Joseph - I mean the first thing that really stood out was the variation in environmental impact, both within and between products. So for staple products, say rice, a high impact farm is creating six times more greenhouse gas emissions per serving than a low impact farm. A pint of beer can create three times more emissions and use four times more land. And so these are two products that look the same in the shop but are actually having pretty dramatically different impacts on the planet. One product that really stood out was beef. So high impact beef uses 750 metres squared of land compared to low impact beef which uses 15 metres squared of land. So that’s a four thousand nine hundred percent difference. And then there are also the differences between products, comparing for example, high impact beef to low impact peas is a twenty five thousand percent difference on greenhouse gas emissions and an eleven thousand percent difference on land use. So yes these are pretty vast differences.

Georgia - You've also looked at things like tea and coffee and chocolate and all my favorite vices. So how much have I damaged the world with all these things I love?

Joseph - I think it's important to have nice things in our life. I think there is the potential to reduce the impacts of what we're consuming or avoid consuming a certain product. Yeah I think we should take it. in a standard bar of chocolate, about 50 grams, the lowest impact bar can effectively create zero greenhouse gas emissions, versus a high impact bar creating about six point seven kilograms of carbon dioxide equivalents. You see the same for coffee, perk up the difference in greenhouse gas emissions ranges from just about 80 grams of CO2 to one point three kilograms for a cup of coffee.

Georgia - And you mentioned your inspiration for doing this was you were worried about your own consumption. You wanted to find out more. So how are you hoping this paper will engineer change?

Joseph - So we put forward a kind of integrated solution at the end and we look at how we can connect consumers with producers and create a chain of accountability throughout the food system. For producers, this is going to be about monitoring their own environmental impacts and take steps to mitigate them and reduce them. We also suggest providing incentives and diverting some agricultural subsidies to do this. Then it's about communicating information to suppliers which could encourage more sustainable sourcing, and then communicating through to consumers and actually enabling consumers to choose between products with high impact, products with low impact, and also producers with high impact and producers with low impact. So connecting the system like this, possibly through a catalyst like a product label, could see real change.


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