How an astrophysicist wrote ‘Food and Climate Change Without the Hot Air’

UIT Cambridge is to publish its first book since lockdown on September 3: Food and Climate Change Without the Hot Air is an explainer on tracking the carbon footprint for everyday consumer items, authored by professor of astrophysics Sarah Bridle.

The new title is the first new title this year for the green imprint based off Chesterton Road, explains Niall Mansfield, who founded the independent publisher in 1992.

“There’s only two publishing seasons – spring and autumn,” says Niall. “So everything that was going to be published in March, April and May didn’t happen and it’s been postponed until the autumn.

“Food and Climate Change couldn’t get printed – there’s been delays of between two and four months – and the distributors have been closed, but even if the distributors were open there would be no shipping-out and even if the shipping-out were possible the bookshops were closed .”

Not that this stopped Niall from giving it a go: UIT had The Dublin Art Book ready for launch in Ireland in the spring, but it has also been postponed until next month, along with another 600 new books also being published in the UK on the same day.

“The book is predominantly for visitors to the city and there aren’t any,” says Niall. “We were due to have an advert printed in one of the Dublin tourist maps – they were going to have 1.2 million copies printed but there was no tourist trade.”

The launch party for Food and Climate Change will take place online on Wednesday (August 26). Many of the issues the book raises are disquieting: products and goods that may seem green can have horrendous carbon bills the consumer doesn’t get to hear about too much. Factors assessed include packaging, the fertiliser to grow crops – including for animal feed – and the methane implications of manure. It’s full of great details, for instance: “A piece of efficiently produced beef causes 15 times its own weight in emissions from cow burps alone.” Who knew?

The densely-packed information encoded into the book’s core values is a triumph for first-time author Sarah Bridle, who was an astrophysicist at the University of Manchester when she started.

“The writing started four years ago,” Sarah says. “In 2015 I had just finished a significant astrophysics project, and the kids had finished school. I was looking around for the next project when I thought about climate change and wondered what if one of the kids asked me in 20 years ‘what did you do?’ and I said: ‘Well I was looking at the stars’. That doesn’t really cut it.”

UIT Books was the obvious choice as publisher, because Sarah’s father had been friends with one of UIT’s most successful authors: David MacKay’s Sustainable Energy Without the Hot Air was published in 2008. In 1997, Sarah was awarded a first class MA degree in natural sciences at the University of Cambridge, followed by a PhD in 2000 on Bayesian methods in cosmology, supervised by Mike Hobson – which meant she worked in the same department as David MacKay.

“Two years after I started writing, when I had a chapter ready, I emailed Niall and we met in London and that was that. I’m thrilled with the way the book looks, I had Dave MacKay’s book on my mind all along and haven’t been disappointed – it looks great.

“The book aims to have a more rational conversation – it’s not about a spat between vegans and farmers . I read that vegans on average cause less climate change than carnivores , but I thought it must be more complicated than that because if I cook my baked potato for two hours that’s two hours of gas or electricity – and that factors into a wider picture of usage.”

This is intricately unpicked in the book, from the carbon impacts of freighting your food by plane or by sea, to how the crops are grown that feed chickens and cattle, and how much land is used to grow your food – all so that you can identify the items which have produced the lowest emissions.

A nifty writing style offers useful comparisons, such as “one can of beer causes emissions similar to those from 30 cups of black tea, four cups of white coffee, a piece of cake, or driving one mile in a fossil-fuelled car”.

And it’s all scientifically validated by 60 pages of notes, references, a bibliography and indexing.

So is there one all-important metric that should be included across all food labels?

“The key bit of information is grammes of carbon dioxide equivalent – gCO2e. That is what is used in academic literature and in IPCC reports.”

The gCO2e metric is a standard unit for measuring carbon footprints. But the proposal needs backing, and not just from food producers.

“I started on this five years ago to work out how to help, and I realised that people can have the technology but it’s not just about technology, it’s about human behaviour – Walkers Crisps used to put the CO2 figure on the packet but no one understood it. Tesco did it for some lines and no one cared – it wasn’t taken up, so they stopped doing it.

“It needs to be mandated by the government.”

Sarah had some experience of government when she worked on a proposed amendment to the Agriculture Bill with the Earl of Caithness to ensure financial help to reduce climate change, with payments linked to actions to reduce and sequester emissions. It didn’t succeed, and she learned that policy change “needs support from many quarters to get traction”.

“The government has enough trouble bringing in a sugar tax, so without the public’s support it’s not going to happen,” she adds.

Food and Climate Change Without the Hot Air is published by UIT Books on September 3, priced £19.99, with a free e-reader version ‘thanks to funding by the University of Manchester’. Register for the August 26 webinar here .