Sarah Bridle, a renowned cosmologist, has made a remarkable career shift by applying her expertise to the field of food. In this exclusive interview, Bridle discusses her journey from studying the cosmos to focusing on the dinner plate, and the impact of her work on the food industry and climate solutions. Bridle's unique perspective offers valuable insights into the intersection of physics, food, and sustainability.
A Shift in Focus
Bridle's interest in food physics began with a personal realization about the importance of David MacKay's work on energy and climate. As she delved into climate change, she discovered the significant role that food plays in global greenhouse gas emissions. This led her to question the efficiency of land use in food production and its impact on climate solutions.
"Land use is the 'dark matter' of climate solutions," Bridle explains. "Most people don't realize that food production accounts for up to a third of global emissions, and in the UK, 70% of land is used for agriculture. We need to address this inefficiency to make way for other climate solutions."
Social and Cultural Factors Dominate
One of the most surprising aspects of Bridle's work in food is the dominance of social and cultural factors. She notes that technical solutions alone are not enough, as people's behavior and decision-making criteria can cancel out the gains of efficient technologies. For example, raising the price of meat to reduce consumption may lead to increased demand for luxury items.
"People don't always behave rationally," Bridle says. "We need to understand the social context and combine quantitative modeling with deeper social insights."
Combining Astrophysics Tools and Food Context
Bridle's background in astrophysics has been instrumental in her approach to food physics. However, she encountered challenges when trying to apply astrophysics tools directly to food. For instance, she attempted to use multispectral satellite imaging to detect blackgrass in wheat fields, but the complexity of soil conditions and other variables made it difficult.
"Astrophysics tools didn't work as expected in the food context," Bridle recalls. "This experience taught me the importance of broader system modeling and integrating more contextual data."
The Future Food Calculator
To address the complexities of the food system, Bridle and her team developed a quantitative model called the 'Future Food Calculator.' This web-based dashboard allows users to explore various interventions, such as on-farm practices, consumer dietary shifts, and land-use choices, and assess their impact on greenhouse gas emissions, self-sufficiency, and land use.
"The calculator helps us understand the trade-offs and unintended consequences of different interventions," Bridle explains. "It's a powerful tool for policymakers and the public to make informed decisions."
Balancing Information and Behavior Change
Bridle emphasizes the importance of balancing information and behavior change. She notes that providing people with information about the health and environmental impacts of food choices is not enough to drive sustainable behavior. Instead, systemic changes that make sustainable choices easy by default are necessary.
"We need to make sustainable choices the default," Bridle says. "Reformulation and choice architecture can play a significant role in this. For example, adding pulses to lasagne can reduce beef content, and putting low-impact options first in canteens can make a difference."
Creating 'Wow' in the Food Industry
Bridle believes that creating a sense of 'wow' in the food industry is essential to engage people. She suggests that community garden projects and other experiential learning opportunities can help people understand the challenges of food production and foster respect for food.
"Experience is key," Bridle says. "Letting people see how hard it is to grow food and how weather impacts yields can create a deeper connection and appreciation for food."
Environmental Labeling and Policy Impact
Bridle also discusses the importance of environmental labeling and its impact on policy. She notes that labels can influence production and consumer behavior, even if they don't significantly shift individual purchasing decisions.
"Labels can drive change at the production level," Bridle explains. "In pilot programs, adding climate labels led operators to change their offerings. In Canada, tighter sugar labels prompted manufacturers to reformulate their products."
The Digital Twin of UK Food
Bridle's team is developing a 'digital twin' of the UK food system, which will allow policymakers to test interventions and assess their impact on greenhouse gas emissions and self-sufficiency. This tool will help identify trade-offs and unintended consequences, ensuring that the UK food system aligns with net-zero targets.
"The digital twin is a powerful decision-making tool," Bridle says. "It allows us to explore different pathways and ensure that the UK food system is resilient and sustainable."
Managing Complexity in Herbicide Use
Bridle highlights the complexity of managing herbicide use, particularly with the example of glyphosate. She explains that no-till farming techniques can reduce emissions but may increase herbicide reliance if weed pressure rises.
"We need to quantify these interactions at the system level," Bridle says. "It's about comparing pathways transparently and understanding the trade-offs, rather than assuming a single intervention is universally better."
Data Practices and Collaboration
Bridle reflects on the data practices in food physics and draws parallels to astrophysics. She notes that astrophysics has made significant strides in open data and collaboration, but food physics still has room for improvement.
"We need standards, shared datasets, open code, and coordinated efforts," Bridle says. "This is similar to the situation in astrophysics 20-30 years ago."
Advice for Aspiring Food Physicists
Bridle offers valuable advice to physicists and mathematicians interested in pursuing a career in food physics. She emphasizes the importance of quantitative modeling, open-source practices, and Python-based tooling.
"Help build transparent models and shared datasets," Bridle suggests. "Join or create collaborative efforts that mirror modern astrophysics consortia. Find your people and seek mentorship."
Practical Steps for Change
Bridle encourages individuals to take concrete steps towards a more sustainable food system. She suggests bringing open-science habits to food-system work, publishing code and assumptions, and contributing to cross-disciplinary teams.
"Make sustainable choices easy by default," Bridle says. "Translate findings into accessible tools for policymakers and the public."
Motivation and Future Success
Bridle's motivation stems from her desire to address the climate crisis and make a practical impact. She envisions a successful UK food system aligned with net-zero targets, efficient land use, and low-impact diets.
"Success means aligning UK production and consumption with net-zero targets," Bridle concludes. "It's about making low-impact diets the default and improving self-sufficiency and resilience. Open, quantitative modeling with transparent code and assumptions should be embedded in policymaking."
