China’s Biochar Strategy Could Scale Carbon Removal on Abandoned Cropland

Biochar has long been considered a potentially valuable climate measure, yet one that has proved hard to expand. The underlying principle is straightforward: plant matter is converted into a durable, carbon-rich material and placed in soil, locking up that carbon for decades or potentially centuries.

The constraint has usually been feedstock. Sufficient surplus biomass is often unavailable in the locations needed for biochar to operate at a major scale.

Fresh research indicates that China may be able to bypass this obstacle by cultivating bioenergy crops on abandoned cropland before processing them into biochar. If it works, this model could allow biochar to grow substantially while costing much less than many rival carbon removal approaches.

“Our work shows that integrating bioenergy crops into the system can significantly expand its potential while keeping costs low,” said corresponding author Wei Li of Tsinghua University.

Biochar’s key carbon advantages

Many carbon removal methods are costly, technically demanding, or both. They can depend on large industrial facilities, considerable electricity use, permanent underground storage or monitoring arrangements that are difficult to roll out at pace.

Biochar works in another way. As plants develop, they absorb CO2 from the atmosphere. Pyrolysis then changes some of the carbon held in the plants into a more resilient and stable material. Instead of being released back into the air, this carbon is stored in the ground.

The material can also provide benefits beyond climate objectives, making the case for its use broader. Biochar may raise soil organic carbon, improve the ability of soils to hold nutrients and, in certain situations, cut emissions of greenhouse gases such as nitrous oxide.

In other words, spending on carbon removal could also enhance agricultural outcomes and lower farm-related pollution.

Biochar’s big supply problem

At present, most biochar is made from agricultural and forestry residues. Using these materials is practical because they already exist, although it also sets a ceiling on the extent to which biochar can grow.

These residues are dispersed across wide areas as well, and moving bulky plant matter over long distances soon becomes costly.

The new research raises an important possibility: rather than depending solely on leftovers, could biochar have a dependable source of biomass grown expressly for the purpose without displacing food production? Abandoned cropland is central to that proposition.

Testing biochar at scale in China

The researchers assessed the combined crop-and-biochar model against real-world limitations. Their analysis considered the location of China’s biomass power stations, transport infrastructure and realistic supply-chain circumstances.

Their calculations indicate that bioenergy crops raised on abandoned cropland could enable about 25.8 million tonnes of CO2 removal each year through biochar.

This is a meaningful amount. It is also broadly similar to the biochar removal potential from agricultural and forestry residues, historically the primary feedstock source.

The proposal is not to displace residues. Instead, it would establish a second source of supply, preventing feedstock availability from continuing to restrict biochar.

Breaking down the costs

A particular estimate is especially notable. According to the study, biochar made through this integrated system would cost around $9.6 per tonne of CO2 removed.

The team contrasts this figure with BECCS, or bioenergy with carbon capture and storage, which is a carbon removal route requiring more infrastructure.

In the researchers’ analysis, BECCS costs about $90.9 per tonne. Although it may remove marginally more carbon in certain configurations, it depends on expensive capture technology, transport and storage infrastructure. Such expense and complexity may hinder efforts to increase deployment rapidly.

“Cost is a critical factor for large-scale deployment,” the authors wrote.

“Biochar stands out because it delivers meaningful carbon removal at a fraction of the cost of alternative technologies.”

For carbon removal plans at a national level, this difference in price is significant. It separates a pilot scheme from an option that could be deployed widely.”

How big biochar could get

The research further considers the outcome of optimising and enlarging the system. This would involve additional energy crops, a greater biomass supply and more pyrolysis plants constructed in suitable locations.

Under this maximum-potential scenario, the researchers calculate that China’s biochar capacity could possibly rise to as much as 1.88 billion tonnes of CO2 removal annually.

That outcome is plainly not imminent: it relies on available land, infrastructure development and continuing policy backing. Nevertheless, it illustrates that biochar need not remain a small-scale option.

Should investment and supply chains come together, it could serve as a substantial tool rather than a specialist addition.

The role of abandoned cropland

Eastern and north-eastern China are identified by the study as areas with particularly strong potential, mainly because they bring together biomass resources and established infrastructure. This is important, since transport costs can discreetly determine whether biochar is economically viable.

Choosing abandoned cropland is also intentional. Bioenergy schemes can attract opposition if they are seen to compete with food production.

Using land that is underused for energy crops is intended to limit that tension and make large-scale deployment more politically achievable.

This is not an ideal answer in every case: “abandoned” land may still offer ecological benefits or support local activities. Even so, it represents a more credible starting point than turning productive farmland over to energy crops.

Barriers to scaling biochar

While the researchers are positive about the prospects, they acknowledge that the approach cannot simply be switched on. Expanding biochar would need spending on pyrolysis facilities, closer links with current agricultural and energy systems, and dependable biomass supply chains.

Policy support and incentives from carbon markets would be equally important, giving farmers and businesses a reason to take up the approach and maintain it.

“Our findings suggest that biochar, especially when paired with bioenergy crops, could become a cornerstone of climate mitigation strategies,” the researchers said.

“With the right policies and investments, it has the potential to deliver both environmental and economic benefits.”

Outlook for biochar

The study recasts biochar as more than a worthwhile concept that has struggled to grow. It suggests substantial expansion is possible if biomass supply is addressed as the main issue.

Cultivating bioenergy crops on abandoned cropland could greatly increase biochar production while keeping costs comparatively low, at least in theory.

As biochar can improve soil health too, it is not merely a climate measure with one function. Rather, it provides a carbon removal route that can be combined with agricultural gains.

For China, if carbon neutrality is a serious objective and it needs options that are practical, scalable and affordable, the research presents a compelling argument for giving biochar greater attention.