She remained in Scotland for her Ph.D., researching malnutrition and global food systems. She created a scalable framework to understand food system pathways and identify losses, allocations and conversions.[2] In particular, she looked to understand whether it was possible to feed a growing population without damaging the environment.[3] Ritchie is vegan.[4]
Ritchie started her career as a lecturerinsustainability at the University of Edinburgh. She developed teaching programs focused on sustainability.[5] She left Edinburgh to start a research position at the University of Oxford, where she developed data visualizations to communicate information.[3]
Ritchie's early work considered food systems and how it was essential to adapt to meet the Sustainable Development Goals.[6] For example, she has argued that for most foods, the carbon footprint is barely impacted by transport.[7]
In 2017 Ritchie joined Our World in Data as Head of Research. Her work focuses on environmental sustainability, including topics such as climate change, energy, food and agriculture, biodiversity, air pollution, and deforestation.[8] During the COVID-19 pandemic, she built the Our World in Data COVID-19 information dashboard.[9] In 2023 she became Deputy Editor and Lead Researcher.[10]
In 2024 Chatto & Windus published Ritchie's first book, Not the End of the World,[11] which explores her optimism for large-scale problem-solving and ending climate change.[12][13]
In 2022 Ritchie was named Scotland's Youth Climate Champion at the Holyrood Green Giant Awards in recognition of her contributions to the climate-change movement.[14] In 2024, Ritchie was recognised for lifetime achievement with honorary fellowship of the Royal Statistical Society.[15]
Hannah Ritchie, "What We Learned from Acid Rain: By working together, the nations of the world can solve climate change", Scientific American, vol. 330, no. 1 (January 2024), pp. 75–76. "[C]ountries will act only if they know others are willing to do the same. With acid rain, they did act collectively.... We did something similar to restore Earth's protective ozone layer.... [T]he cost of technology really matters.... In the past decade the price of solar energy has fallen by more than 90 percent and that of wind energy by more than 70 percent. Battery costs have tumbled by 98 percent since 1990, bringing the price of electric cars down with them....[T]he stance of elected officials matters more than their party affiliation.... Change can happen – but not on its own. We need to drive it." (p. 76.)
