Perennial Biomass
Deep-rooted grasses on land too tired to farm. They hold the soil, need almost nothing, and can be cut year after year.
The effect compounds within years. Put it in place and it keeps working.
Project Drawdown classifies this as Gradual.
Origins
The prairie was the model, and we destroyed it before we understood it.
The North American tallgrass prairie built some of the deepest, richest soils on Earth, and it did so with perennial grasses whose roots went down three, four, five metres. Those roots were the point. They held the soil through drought, rebuilt it every season, and pushed carbon down into the subsoil where it stays for centuries. When the sod-busting ploughs arrived in the nineteenth century, they cut through a root mat that had taken ten thousand years to weave. Within two generations we had the Dust Bowl.
The lesson was drawn slowly and by an outsider. Wes Jackson, founding the Land Institute in Kansas in 1976, asked a question that agronomy had not bothered to ask: why does agriculture use annual plants, which must be replanted every year, when the ecosystem it replaced was built on perennials that did not? His answer — that we had inherited an accident of the Neolithic rather than an optimum — is still radical, and his institute has spent fifty years trying to breed perennial grain crops to prove it.
Perennial biomass is the more modest cousin of that idea, and the one that is ready now. Not perennial wheat, but perennial grasses grown deliberately on land that annual agriculture has already used up: miscanthus, switchgrass, and their relatives. Plant once. Harvest for twenty years. Leave the roots in the ground.
What it actually is
There is a great deal of land in the world that is neither forest nor productive farm: ground that was cleared, cropped until it was exhausted, eroded, and abandoned. It is not doing anything useful, it is frequently still losing soil, and it is one of the few genuinely uncontested land categories in the climate debate.
Perennial biomass crops are one of the few things you can do with that land that improves it rather than mining it further.
Because they are perennial, they are planted once and harvested for many years. The root system stays in the ground through winter, holding soil that would otherwise wash away, feeding soil biology, and pushing carbon into the subsoil where it is far more stable than carbon near the surface. They need little fertiliser and no annual ploughing — and ploughing is where a very large share of agricultural emissions and nearly all agricultural soil loss come from.
The harvest becomes fuel, fibre, or feedstock: heat, power, biochar, building material, bioplastic. It substitutes for something fossil.
And then comes the honest caveat, which is fundamental rather than incidental: biomass is only a climate solution when it does not displace something better. Grow energy crops on land that could feed people, or clear forest to plant them, and the accounting turns sharply negative. The entire case rests on the land being genuinely marginal — and on the discipline to say so when it is not.
The numbers
Roots are the whole story. Perennial grasses put a large share of their biomass below ground and keep it there. Soil carbon accumulated below the plough layer is substantially more durable than carbon near the surface, which is exactly what annual cropping disturbs every year.
No tillage, no fertiliser, no erosion. Removing the annual plough pass eliminates the single largest source of agricultural soil loss and a significant share of its emissions. Perennial biomass needs a fraction of the nitrogen an annual crop requires, and nitrogen fertiliser is itself a major emissions source through nitrous oxide.
The land test is everything. Drawdown’s current framing names the qualifier explicitly: biomass crops on degraded land. Grown on cropland, biomass competes with food. Grown on cleared forest, it is a catastrophe. Grown on abandoned, eroded ground, it is a genuine gain. Same plant, three completely different answers.
Modest, and honest about it. This is not a gigaton-scale hero solution and should not be sold as one. It is a way to make degraded land useful, keep carbon in soil, and displace some fossil energy. That is worth doing and it is not worth exaggerating.
Why it matters
Every farming culture has a piece of ground it gave up on.
The field that would not hold its soil. The slope that eroded. The paddock that was cropped one generation too many and now grows thistles and nothing else. In almost every farming family there is a memory of land that was worked until it stopped answering, and there is something like shame in it, quiet and unspoken, because a farm is meant to be handed on in better shape than it was received.
Perennial biomass is, more than anything else on this list, a way of putting that right.
You do not need to convert the whole farm. You do not need to stop being a farmer or apologise for being one. You put deep roots back into the ground that lost them, and the roots hold the soil, and the soil starts to come back, and in twenty years the field is worth more than it was when you inherited it. That is not an environmental sacrifice. That is repairing a thing that was broken on your watch or your father’s.
The prairie built those soils with roots over ten thousand years. We removed them in fifty. Putting them back is not a radical act. It is closer to an apology, and the land accepts apologies remarkably readily.
What it actually takes
Deciding, honestly, what land is actually marginal. This is the whole solution and it is the whole risk. “Marginal land” is a phrase that has been stretched to cover grassland, savanna, fallow that people were grazing, and common land that somebody was quietly using. Defining it loosely is how biomass programmes end up destroying ecosystems and displacing the poor.
Patience through establishment. Perennial grasses take two to three years to establish before yielding properly. A farmer needs to survive those years, and most support schemes are not designed for a crop that pays nothing until year three.
A market at the other end. Biomass with no buyer is hay. The value chain — a power station, a pellet plant, a biochar kiln, a fibre mill within economic distance — determines whether any of this happens. This is infrastructure policy dressed up as agriculture.
Not letting the accounting drift. Bioenergy has an unhappy history of carbon accounting that assumed regrowth would compensate for combustion and then did not check. Perennial biomass on degraded land is defensible. The same logic stretched to justify burning forests is not, and the industry has form.
Where it matters most
The abandoned and eroded farmland of the temperate world is the honest home for this: the marginal margins of the Great Plains and the Corn Belt, land cropped past its capacity and now producing very little.
The North German Plain and the English Midlands are where miscanthus has been most seriously trialled, on intensively farmed land where soil organic matter has been falling for decades.
The Loess Plateau of China is the great object lesson in what perennial cover can do for eroding ground, and the largest deliberate landscape restoration ever attempted.
Post-industrial and post-mining land — the spoil heaps and contaminated ground of the old coalfields — is the most uncontroversial use of all, and the one nobody argues about.
Where it must not go: intact native grassland. The Canadian Prairies and the Blackland Prairie hold remnants of the very ecosystem this solution imitates. Ploughing native prairie to plant a prairie grass monoculture would be an irony too far.
How to tell it’s being done well
What was this land doing before? If the answer is “grazing” or “fallow” or “food,” be sceptical. If it is “eroding and abandoned,” proceed. The definition of marginal is where this solution is won or lost.
Is anyone measuring soil carbon at depth? The entire case rests on carbon going down. Surface-layer measurements will miss most of it and can be gamed. Depth-adjusted, multi-year measurement or it is a story.
Is the end use displacing fossil fuel, or displacing food? Both are called bioenergy. Only one is a climate solution.
Would native prairie restoration have been better? Sometimes the answer is yes, and an honest project will say so. A monoculture of switchgrass is not a prairie, and on some land the prairie is the better use.
What you can do
Anyone
- When you hear biomass energy, ask what the feedstock is and where it grew. Burning wood pellets from clearcut forest and growing grass on abandoned mine spoil are both called biomass and are not remotely the same thing.
Landowners and farmers
- If you have a field that has stopped answering, perennial cover will hold it and start rebuilding it, and it will pay something while it does.
- Budget for three years before the first real harvest. This is the barrier that stops most people, and it is the one to plan for.
- Consider whether native prairie restoration would be better on that ground. Sometimes it will be.
Policymakers
- Define marginal land narrowly and in law. Loose definitions are how bioenergy programmes end up clearing forest and displacing farmers.
- Support the establishment years. A crop that pays nothing until year three does not fit a scheme designed around annuals.
- Build the demand. Without a buyer within economic distance, none of this happens.
Business and investors
- The processing and offtake infrastructure is the bottleneck, not the agronomy.
- Insist on land-use verification. Biomass carbon accounting has a poor history and the reputational exposure is real.
Where this matters most
Who is working on this
We are researching which organizations in our directory of 8,493 actively work on this solution, and we only list an organization once we have verified it. That research is ongoing. In the meantime, search the directory yourself:
Questions
Is growing crops for energy actually good for the climate?
Only conditionally, and the condition is the land. Perennial biomass grown on degraded, abandoned land builds soil, holds it, and displaces fossil fuel: a genuine gain. The same crop grown on cropland competes with food, and grown on cleared forest it is a disaster. The land it grows on decides the answer entirely.
Why perennial rather than annual crops?
Perennials are planted once and keep their roots in the ground year-round. That means no annual ploughing, far less erosion, much less fertiliser, and steady accumulation of carbon deep in the subsoil, where it is far more durable than carbon near the surface. Annual tillage is where most agricultural soil loss and a large share of its emissions come from.
What counts as marginal land?
This is the crux, and it has been abused. Genuinely marginal land is ground that was previously farmed, is degraded or eroded, and is no longer productive enough for food. It is not fallow that someone is grazing, not common land somebody quietly depends on, and certainly not native grassland. Loose definitions are how biomass programmes cause harm.
Isn't burning biomass just burning carbon?
It releases carbon, yes. The climate case rests on that carbon having been drawn down recently by the plant, and on it displacing fossil carbon that would otherwise have been added to the atmosphere from underground. This logic is defensible for perennial grass on degraded land. It has been stretched, dishonestly, to justify burning forests, and that history is a fair reason for scepticism.
How much carbon does it actually store?
This is a modest solution and should not be oversold. Its value is in making degraded land useful, keeping carbon in soil below the plough layer, and displacing some fossil energy. That is worth doing. It is not a gigaton-scale hero and anyone presenting it as one is not being straight with you.
Would restoring native prairie be better?
On some land, yes, and a good project will say so rather than defend its monoculture. A switchgrass plantation is not a prairie. Where native grassland restoration is feasible and the ecosystem is recoverable, that is usually the better use of the ground.
Sources
- Project Drawdown - Deploy Biomass Crops on Degraded Land (Drawdown Explorer) Framework and classification. Cited, not reproduced.
- IPCC (2022), AR6 Working Group III - Bioenergy and land
- The Land Institute - perennial agriculture research
- Griscom et al. (2017), PNAS - Natural climate solutions
The solution taxonomy follows the framework popularised by Project Drawdown. The analysis above is our own; for their carbon modeling and rankings, visit them directly.