Using Your Loaf - The Environmental Impact of Bread

With about 99 percent of UK households regularly buying bread, it’s fair to say it’s become the “bread and butter” of the British diet. The average Brit consumes 2-3 slices daily and nearly 12 million loaves are sold every day. But what does this mean for the environment? With such a significant amount being bought and consumed, surely there is some effect? Read on for a review of bread’s environmental impact.

Farm to shelf

To analyse the impact of the staple food, the University of Sheffield explored its emissions all the way from the farm to the shelf where it’s sold. Their study – published in the journal Nature Plants – found that the biggest factor was fertiliser. While some products cause most harm in transport, it is the wheat-growing fertiliser that accounts for the most greenhouse gas emissions in bread production, totalling 43 percent.

This large proportion of the total also means that growing wheat was found to be the most significant part of the bread making process from the following areas of analysis:

·         Growing and harvesting wheat

·         Milling the wheat grain

·         Producing flour

·         Baking bread

·         Final loaf production in the shop

A big slice of the emissions loaf

Because of the energy used to power large machines, milling and bakery followed wheat growing as the biggest contributors. But it is the use of fertiliser that has got researchers thinking.

"With over 100 million tonnes of fertiliser used globally each year to support agricultural production this is a massive problem, but environmental impact is not costed within the system and so there are currently no real incentives to reduce our reliance on fertiliser," said Professor Peter Horton, one of the study’s researchers.

Monitoring emissions

So how do fertilisers actually cause emissions? It’s simple – a significant amount of fertiliser dosage enters the atmosphere each time it is used. The chemicals that are emitted include carbon dioxide, methane, nitrogen and ammonia. As well as being more damaging compared to other aspects of the bread-making process, it's seemingly the most preventable.

Pesticides cause similar issues, with emissions from each dosage. The first challenge, however, is monitoring the emissions. There are several methods and techniques being developed to give a more accurate overview of the impact. But, as discussed in the article ‘Challenges Facing Pesticide Analysis and Monitoring - An Interview with Dr. Simone Hasenbein’, there is also a need to make these methods faster, more efficient and cheaper.