Rice is as American as takeout Tuesday and sushi night. It’s on the shelves of every grocery store, appears in everything from burrito bowls to stir-fries, and feeds more than half the world’s population. But a growing body of research is asking a question most of us have never stopped to ask: Is the way we grow rice quietly breaking the planet?
Mahmood, Ghani, and Gheewala tackled that exact question in a 2023 study, ‘Absolute environmental sustainability assessment of rice in Pakistan using a planetary boundary-based approach’ in Sustainable Production and Consumption, using a technique called planetary boundary-based life cycle assessment, or PB-LCA. This framework does something that traditional environmental studies don’t measure, namely, whether the total impact of producing a food actually stays within the safe operating limits of Earth’s natural systems. Mahmood et al. discovered that rice production surpassed the safe operating space for a range of important categories, including climate change, freshwater eutrophication, and water use, thereby contributing to the triple planetary crisis described by scientists.
What are planetary boundaries?
Imagine that the Earth has a number of linked systems, like the climate, the water cycle, and flows of nutrients that have a natural limit. If you push those limits too far, you risk pushing the planet into conditions that are harder and harder to reverse. Nine such limits have been identified by scientists. Four are especially pertinent to food systems: climate change, freshwater use, land use, and nutrient pollution from nitrogen and phosphorus. PB-LCA follows the whole path of a food; in this case, from flooded paddies to packaged grain, and checks if every step respects these planetary guardrails. According to the Frontiers Planet Prize study, ‘Harnessing Planetary Boundaries in Rice Farming,’ which recognized this research, the approach incorporates Earth’s carrying capacity into the evaluation of farming practices to keep food production within ecologically safe operating spaces.
