Leaves are already growing on crops we cultivate
In the quiet space between ordinary harvests and unthinkable catastrophe, a University of Canterbury researcher is asking humanity to look more carefully at what it already grows. David Denkenberger and his colleagues are developing methods to extract protein and sugar from the leaves of crops we already cultivate — material currently discarded — as a hedge against disasters that could collapse global food systems. The work is grounded in historical precedent: volcanic eruptions and solar storms have disrupted civilizations before, and billions now depend on supply chains that would not survive them. What makes this research unusual is that it does not require catastrophe to justify itself — the efficiency gains are real enough for ordinary farming to make it worthwhile today.
- Global food systems are more fragile than most people realize — a single volcanic supereruption or extreme solar storm could block sunlight or disable electrical grids, triggering mass starvation across continents.
- The urgency is compounded by the fact that no serious infrastructure currently exists to feed billions of people if conventional agriculture collapses, leaving a dangerous gap between risk and readiness.
- Denkenberger's team is working to close that gap by turning discarded crop leaves into protein concentrate and fermentable sugar — food extracted from land already in use, without clearing a single new acre.
- The dual-use nature of the technology is its strategic strength: farmers could adopt it now for economic and sustainability reasons, embedding the knowledge and infrastructure into the system long before any crisis demands it.
- ALLFED is pushing the work beyond the laboratory into policy and implementation, recognizing that scientific solutions mean little if governments haven't planned and companies haven't invested before disaster strikes.
David Denkenberger has spent more than a decade asking a question most people prefer to avoid: what do we eat when the food system stops working? The University of Canterbury associate professor has now turned his attention to an answer that is almost disarmingly simple — leaves. The green matter growing on wheat stalks and alfalfa plants, material currently discarded or fed to livestock, may hold the key to feeding people through catastrophe.
The scenarios driving this research are rare but not theoretical. A massive volcanic eruption could inject ash into the stratosphere and collapse crop yields for years. An extreme solar storm could disable electrical grids across continents, severing the infrastructure that moves food from farms to cities. Both have happened before in human history. If they happen again, the billions who depend on modern food supply chains would find those chains simply gone.
Denkenberger began this work in 2011, eventually publishing a book and co-founding ALLFED — the Alliance to Feed the Earth in Disasters — in 2017. The organization now bridges scientific research, policy, and practical implementation, built on the recognition that feeding people through catastrophe requires more than laboratory results. It requires governments to plan and systems to be built before crisis arrives.
What distinguishes the leaf protein research is its dual purpose. A wheat field could yield both grain and processed leaf protein from the same crop. Grazing land planted with alfalfa or clover — plants humans cannot eat directly — could be converted into human food ingredients. The efficiency gains and sustainability benefits are real and immediate, meaning farmers could adopt the technology for entirely ordinary economic reasons. If catastrophe then arrives, the infrastructure and expertise would already be embedded in the system.
Denkenberger envisions the work eventually expanding through citizen science, becoming less the province of specialists and more a shared project of resilience. The goal is neither apocalyptic nor utopian — simply practical: develop the tools now, so that when systems fail, humanity has already thought through what comes next.
David Denkenberger sits at the intersection of two worlds that rarely meet: agricultural science and catastrophe planning. For more than a decade, the University of Canterbury associate professor has been asking a question that most people would rather not contemplate: what do we eat when the food system stops working?
His latest answer is surprisingly mundane. Leaves. The green matter that grows on wheat stalks, alfalfa plants, and a thousand other crops we already cultivate—material we currently discard or leave for livestock. Denkenberger and his colleagues are investigating whether these leaves can be processed into protein concentrate, and whether the leftover fiber can be converted into sugar. The result would be additional human food extracted from land already under cultivation, with no need to expand farms or clear new ground.
The research emerges from a specific set of catastrophic scenarios. A massive volcanic eruption could inject ash into the stratosphere, blocking sunlight for months or years and collapsing crop yields globally. An extreme solar storm could disable electrical grids across continents, crippling the infrastructure that moves food from farms to cities. These events are rare, but they are not theoretical. They have happened before. And if they happen again, billions of people depend on food systems that would simply stop working.
Denkenberger began this line of work in 2011, eventually publishing a book titled "Feeding Everyone No Matter What" and co-founding the Alliance to Feed the Earth in Disasters (ALLFED) in 2017. The organization now spans scientific research, policy work, and practical implementation—a recognition that understanding how to feed people through catastrophe requires more than laboratory results. It requires governments to listen, companies to invest, and systems to be built before crisis arrives.
But the leaf protein research is not purely defensive. Denkenberger emphasizes that the same technology could reshape agriculture in ordinary times. A wheat field could yield both grain and processed leaf protein from the same crop. Grazing land planted with alfalfa or red clover—plants humans cannot directly eat—could be converted into human food ingredients. The efficiency gains are real. The sustainability benefits are immediate. The catastrophe preparedness is a bonus.
This dual purpose matters. It means the research does not require society to accept a grim premise to justify the work. Farmers could adopt leaf protein processing because it makes economic sense, because it increases yields, because it reduces waste. If a catastrophe then arrives, the infrastructure and expertise would already exist. The knowledge would be embedded in the system.
As the research advances, Denkenberger sees room for broader participation. Citizen science could help test and refine these methods. The work could become less the province of specialists and more a shared project of understanding how to feed ourselves, whether in ordinary times or extraordinary ones. The goal is neither apocalyptic nor utopian. It is simply practical: identify the tools that exist now, develop the ones that don't, and ensure that when systems fail, people have already thought through what comes next.
Notable Quotes
We're looking at different options that could be used if conventional food production were disrupted. Leaf protein is one of many possibilities, but it could play an important role in improving resilience.— David Denkenberger, UC Associate Professor
The Hearth Conversation Another angle on the story
Why focus on leaves specifically? There must be other plant materials we're not using.
Leaves are abundant and already growing on crops we cultivate. We're not asking farmers to plant something new—we're asking them to harvest what's already there. That's the elegance of it.
But can you actually extract enough protein to matter? What are the yields like?
That's exactly what the research is determining. The early work suggests you can get meaningful quantities, but the real question is whether the processing is efficient enough to be practical at scale. That's where the engineering comes in.
You mentioned this could help in normal times too. How does that work economically?
If a farmer can get additional revenue from processing crop leaves into protein, or if it reduces waste, then it makes sense regardless of catastrophe. The catastrophe scenario is the insurance policy. The everyday benefit is the business case.
What's the biggest obstacle right now?
Scaling. We can extract leaf protein in a lab. Making it work on a farm, with existing equipment and economics, is a different challenge entirely. That's where ALLFED's policy and implementation work becomes crucial.
Do you think governments are actually preparing for these scenarios?
Some are beginning to. But most food security planning still assumes the system will keep working. That's changing slowly, as people recognize that rare events do happen, and the cost of being unprepared is catastrophic.