Feeding the World without Costing the Earth | The Royal Society

Why It Matters

Because feeding a growing global population without expanding farmland is essential to prevent irreversible biodiversity loss and climate destabilisation, directly affecting food security, economies, and planetary health.

Key Takeaways

• Modern agriculture outpaces population growth but drives biodiversity loss.
• Reducing ruminant meat consumption cuts extinction risk and emissions.
• Food waste taxes and campaigns can lower waste by 20‑30%.
• Closing yield gaps on average farms can halt cropland expansion.
• Land‑sharing lowers yields; requires subsidies to protect habitats.

Summary

The Royal Society talk examined how humanity can feed a projected eight‑to‑ten billion people without further degrading the planet. Andrew highlighted that modern agriculture has remarkably outstripped population growth since 1961, yet it now underpins a biodiversity crisis, accounting for roughly 30 % of global greenhouse‑gas emissions, extensive soil depletion, and the loss of habitats that threatens over a third of species. Key data points underscored the urgency: amphibian, reptile and fish populations have collapsed by three‑quarters since the 1970s, and cropland demand could triple in parts of sub‑Saharan Africa by 2075. The speaker argued that demand‑side actions—cutting ruminant meat, curbing bio‑fuel crops, and reducing food waste through taxes and public campaigns—can cut emissions and extinction pressure, but alone they fall short of stabilising land use. Illustrative examples included Charles Godfrey’s warning that “if we fail on food we fail on everything,” Emma Garnett’s experiments showing that simply doubling vegetarian options in buffets boosted plant‑based uptake by up to 80 %, and London’s one‑month advertising ban that slashed household calorie purchases by 7 %. The analysis also presented Yi Gong’s model, which shows that only a combined shift toward low‑meat diets, halved food waste, and a 25 % closure of yield gaps can prevent further cropland expansion. The overarching implication is clear: meeting future food needs while preserving biodiversity demands a dual strategy. Policymakers must pair demand‑reduction measures with aggressive investment in yield‑gap research and sustainable farming practices, recognizing that land‑sharing alone reduces yields and requires compensation mechanisms. Only an integrated approach can halt habitat loss, curb emissions, and secure food security for the coming decades.

Original Description

The Environment Medal and Lecture 2025 is awarded to Professor Andrew Balmford FRS for groundbreaking contributions to conservation science, having built transformative partnerships and redefining the landscape of conservation education.

Food production does more damage to wild species than any other sector of human activity, yet how best to limit its growing impact is greatly contested. Looking first at recent progress in encouraging less damaging diets and trying to cut food loss and waste, Professor Balmford will conclude that both are essential but far from sufficient. On the production side, field studies from five continents quantifying the impacts of different farming systems on almost 2000 individually-assessed species reveals, perhaps surprisingly, that land-sparing – adopting high-yield farming to in order make space nearby for natural habitats – consistently outperforms approaches focused on retaining wildlife within farms. Sparing also offers considerable potential for mitigating climate change. But delivering land sparing raises important challenges—in particular, identifying and promoting sustainable higher-yielding farm methods that are less environmentally harmful than current industrial agriculture, and devising mechanisms which ensure yield gains also deliver habitat conservation. These findings challenge current conservation orthodoxy but suggest that without novel collaborations between conservation and the agriculture sector we will not succeed in bending the curve of biodiversity loss.

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