• Milk is a staple in diets around the world — from lattes to breakfast cereals.
• However, not all milk is created equal when it comes to environmental sustainability.
• This project compares the ecological footprints of dairy and plant-based milks across four key factors:
  • Land use
  • Greenhouse gas emissions
  • Water consumption
  • Eutrophication (pollution)

class: animated, fadeIn

• The dataset and image used in this project are derived from Our World in Data, an open-access platform based on a global meta-analysis of food system impacts by Poore & Nemecek (2018).
• This study assessed environmental impacts from production to packaging across various milk types. The image below provides a visual comparison of environmental metrics per liter of milk, highlighting dairy vs plant-based options.

class: animated, fadeIn

class: animated, fadeIn

class: animated, fadeIn

class: animated, fadeIn

class: animated, fadeIn

class: animated, fadeIn

• Dairy milk ranks highest in land use, GHG emissions, water consumption, and eutrophication.
• Almond milk performs well in most categories but has very high water use due to intensive irrigation.
• Oat and soy milk consistently show lower environmental impact across all metrics.
• The heatmap clearly illustrates this hierarchy of sustainability by impact intensity.
• The radar-bubble plot helps profile and normalize impacts, showing plant-based milks outperforming dairy in every dimension.
• While all plant-based milks are environmentally preferable, oat milk stands out as the most balanced choice.

Conclusion

• This analysis reinforces the evidence that dairy milk has the highest ecological footprint per liter produced.
• Plant-based milks, especially oat and soy, are more sustainable alternatives in terms of land use, emissions, water use, and pollution.
• Visualising multiple environmental metrics side-by-side enables data-driven, ethical decision making about diet and sustainability.
• While no milk is impact-free, the choice of plant-based milks can significantly reduce personal and collective environmental harm.
• Based on this study, switching from dairy to oat or soy milk is a clear, evidence-based action for consumers seeking a lower-impact lifestyle.

References

• Poore, J., & Nemecek, T. (2018). Reducing food’s environmental impacts through producers and consumers. Science, 360(6392), 987–992.
• Our World in Data: https://ourworldindata.org/environmental-impacts-of-food
• R Packages: ggplot2, dplyr, knitr, readr, janitor