Sweeping changes to how the world produces, consumes, and wastes food could prevent a land crisis of unprecedented scale — and help avert cascading climate, biodiversity, and social disruptions — scientists said on Wednesday.
In a Nature paper, 21 researchers outlined a roadmap to restore half of all degraded land by 2050, slash food waste by three-quarters, and shift diets towards sustainable ocean-based foods. Together, they argue, these changes could spare or restore 43.8 million square kilometres of land — an area larger than Africa — while cutting greenhouse gas emissions by an estimated 13 gigatonnes a year.
The implications extend far beyond environmental restoration. The scientists warn that without such interventions, mounting land degradation will undermine food and water security, force migration, fuel social unrest, and deepen economic inequality.
“Land degradation isn’t just a rural problem,” said Barron J. Orr, chief scientist at the UN Convention to Combat Desertification. “It affects the food on all our plates, the air we breathe, and the stability of the world we live in.”
A Convergence of Crises
Current food systems account for over 21% of global greenhouse gas emissions, drive 80% of deforestation, and consume 70% of the world’s freshwater. Without reform, the proportion of Earth’s ice-free land used for food could rise from 34% today to 42% by 2050 — an expansion that would push the planet deeper into climate instability.
The scientists emphasise that the solution lies in integrating land and marine food systems. Replacing 70% of unsustainably produced red meat with seafood and seaweed-based products could free up 17.5 million sq km of pasture and feed land, while offering nutritional benefits to millions, particularly in regions prone to micronutrient deficiencies.
Meanwhile, tackling food waste — which claims one-third of all food produced and costs the global economy US$1 trillion annually — could spare 13.4 million sq km of agricultural land. Policies such as Spain’s new law mandating surplus food donations and banning the rejection of “ugly” produce are cited as scalable models.
Social and Economic Stakes
The paper’s authors stress that reforms must prioritise smallholder farmers and Indigenous communities, who manage much of the world’s agricultural land but often lack access to technology, secure land rights, and fair markets. Redirecting subsidies away from industrial agriculture toward sustainable small-scale farming, they argue, would not only slow land degradation but also strengthen rural economies and social stability.
Failing to act, they warn, will lock in a vicious cycle: declining soil fertility, falling water tables, and shrinking biodiversity will make land restoration exponentially more expensive and politically fraught.
“Food production alone already drives nearly a fifth of global emissions,” said co-author Elisabeth Huber-Sannwald of Mexico’s Instituto Potosino de Investigación Científica y Tecnológica. “If we do not change how we farm and consume, the combined pressure on ecosystems and societies will be overwhelming.”
Policy Coordination Needed
The researchers call for the UN’s three Rio Conventions — on climate change, biodiversity, and desertification — to align strategies and pool resources. The 197 parties to the UNCCD, they note, have already agreed to target soil and land degradation in agricultural areas, but coordination across treaties could accelerate reforms and provide consistent policy signals to governments and markets.
The study’s authors frame the challenge as an opportunity: a chance to reimagine land not as a resource to exploit, but as a living ally in securing a stable, equitable, and climate-resilient future.
“By transforming food systems, restoring degraded land, and harnessing sustainable seafood, we can ‘bend the curve’ of land degradation,” said lead author Fernando T. Maestre of King Abdullah University of Science and Technology. “The science is clear. The question is whether we act in time.”