Geologic CDR is on the back burner in China, compared to the biologic methods of CDR

When it comes to CDR development in China, biologic methods such as afforestation and post-harvest soil turning are widely used CDR methods, while geologic methods such as direct air capture with underground storage and enhanced rock weathering are only in the experimental stage. After all, biologic methods usually involve low-cost, low-tech processes such as tree planting and soil plowing — processes that have a long history of use. In contrast, geologic methods of CDR commonly are technically intensive either in their engineered processes or their measurement and verification of CO₂ captured. They also are expensive and untested at a large scale.

China has completed afforestation for CDR on more than 773,000 sq km (298,000 square miles) of land since 2012, an area larger than the entire land areas of Italy and Spain combined. China began large-scale afforestation in 1978 to combat desertification in the northern parts of the country.

Decarbonizing China

China emits more CO₂ than any other country, but emits less per capita than some of the other large developed countries such as the United States, Canada, and Russia. Emissions in China had been climbing annually until recently when emissions either leveled off or declined.

As the largest greenhouse gas emitter in the world, China has a national goal (Nationally Determined Contribution) of reducing its greenhouse gas emissions by 7% to 10% by 2035 from its peak levels of emissions that are expected to be reached before 2030. China aims to be carbon neutral by 2060.

To reach its decarbonization goals, China employs a variety of climate change tools that are used in many of the world's other industrialised countries, ranging from emissions reduction projects, to carbon dioxide removal and carbon offset markets. These efforts are being pursued against a backdrop of China's rising energy consumption — much of it coal-fired.

But decarbonization strategies using geologic methods of CDR such as direct air carbon capture and storage (DACCS), enhanced rock weathering (ERW), or ocean alkalinity enhancement (OAE) are receiving only their first looks in China, while some of these methods are seeing their first large-scale deployments elsewhere in the industrialized world.

A large part of China's decarbonizing strategy involves reducing emissions from the country's more than 1,100 coal-fired electric power plants. The current focus is on carbon capture, utilization, and storage (CCUS) projects. A CCUS project involves capturing CO₂ from the exhaust flue of a coal power plant and then storing the captured CO₂ long-term by injecting it into the pore spaces inside rock underground (mostly in enhanced oil recovery projects). Incorporating the captured CO₂ into a long-lived products such as cement is another approach to long-term CO₂ storage in a CCUS project. CCUS does not capture CO₂ from the atmosphere and, therefore, is not a carbon dioxide removal method; it is an emissions reduction process.

The largest CCUS project in the world is being constructed at a coal-fired power plant in the Longdong Energy Base, in Gansu Province. The project will capture 1.5 million tonnes of CO₂ per year from the plant, with most of the CO₂ being injected underground to boost crude oil production in aging oil fields (enhanced oil recovery).

Although geologic methods of CDR have not been implemented in China, they are receiving attention in technical papers and in limited pilot-scale projects.

Direct air carbon capture and storage (DACCS) in China

Over the past two decades researchers at universities in China have published numerous technical papers focusing on the basic science and engineering of DACCS. One recent paper explained how in the quest for net-zero, DACCS could complement China's emerging scale-up of the biologic CDR method, bionergy carbon capture and storage (BECCS). In BECCS, biomass is burned in an industrial plant to produce either liquid fuels or electricity and captures and stores its CO₂ emissions underground. The relatively small land use requirements of DACCS would not compete with BECCS's use of land for crops.

China's first step toward actually performing DAC was announced in 2024 by researchers at Shanghai Jiao Tong University (SJTU) and China Energy Engineering Corporation who jointly developed a small-scale modular DAC unit called the CarbonBox. One CarbonBox module has a capture capacity of 600 tons of CO₂ per year. The unit is housed in a 40-foot long container, enabling installation of multiple units together for scaling up.

A CarbonBox could serve as a component of a CDR system if coupled with durable storage of captured CO₂ underground, thus comprising a DACCS system. Or, the captured CO₂ could be incorporated into a long-life product such as cement. The captured CO₂ can also be used for manufacturing liquid methanol fuel. A CarbonBox system would need to be powered by a low-emission source for the system to have low or zero emissions.

Storing captured CO₂ by underground injection or incorporating CO₂ into products has recently been discussed in Chinese technical publications. These discussions are largely aimed at emissions reduction (CCUS), although information about geologic storage underground would be applicable to DACCS, as well.

Much of China is underlain by rock layers suitable for CO₂ injection in DACCS projects (see map below). There are several large sedimentary basins where CO₂ could be injected into sandstone layers in DACPS projects. Smaller areas in China are underlain by igneous rocks such as basalt (areas shaded green on the map) that would be suitable for injection in DACCM projects. A study estimated that basalt in China has between roughly 250 and 850 GtCO₂ storage capacity, depending on the injection design.

The China Geological Survey recently published a revised estimate of potential storage volume in sedimentary rocks in China. The estimate was for storing CO₂ captured from industrial emissions (emissions reduction), and did not mention direct air capture. Referring to China's pledge to achieve carbon neutrality by 2060, the publication says, "Carbon capture and storage (CCS) will play a key role in these efforts." The study concluded China has the capacity in its layers of sedimentary rocks to store between 48 and 164 GtCO₂ underground.

A paper published in the Journal of Geo-Energy and Environment in 2025 points out there are still many uncertainties in the geological storage of carbon dioxide in China. "The ownership of storage sites is unclear. There is a lack of standards or specifications for storage site selection. Also there is a deficiency in the regulatory framework for safety monitoring and leakage emergency response after storage, with relatively insufficient technologies and experience.", the authors wrote. They concluded, "Pure carbon dioxide storage is constrained by policies and costs in the short-term, making it difficult to achieve rapid development. In the near future, it will be dominated by demonstration projects."

Enhanced rock weathering (ERW) in China

Although ERW has not yet been tested on a large-scale in China, a study published December 2025 issue of Earth-Science Reviews (Elsevier) says, "China's extensive basalt reserves, diverse climatic conditions, and vast agricultural lands create favorable conditions for large-scale ERW implementation."

Basalt from the areas in China shaded green on the preceding map of sedimentary basins could potentially serve as feedstock for ERW. In an ERW project, the basalt would be mined, ground to a fine grain size, and then transported by truck or rail to croplands where it would be spread on soil. On cropland, basalt particles react with rainwater and soil, to form alkaline compounds such as bicarbonate that eventually makes its way to the ocean via a soil water—ground water—river flow path.

A 3-year field study reported that mixed silicate rock powder applied to cropland in different climate regions in part of China increased crop yield by about 7% and carbon capture of the soil by 1.6-2.4 times.

A new life-cycle assessment highlighted China's extensive basalt reserves, diverse climatic conditions, and vast agricultural lands as providing suitable conditions for large-scale ERW deployment. Depending on the grain size of ground basalt, ERW could sequester 0.2 GtCO₂ by the year 2100 (larger grain size), or as much as 0.5 GtCO₂ by 2060 (smaller grain size). This compares to the total of 1,000 gigatonnes needing removal within the next century in order to cap global warming at 1.5^oC above pre-industrial times (circa 1850) — using all types of CDR (estimate by the IPCC). Despite its potential, ERW faces challenges, including potential heavy metal release, uncertainties in long-term weathering rates, and cost constraints.

One group of researchers conducted a set of field monitoring experiments that evaluated crop productivity and carbon dioxide removal across semi-arid, semi-humid, and humid regions in China. The study concluded ERW in China could potentially remove between 0.28 and 0.40 GtCO₂ per year.

Ocean Alkalinity Enhancement (OAE)

OAE involves increasing the alkalinity (buffering capacity) of the ocean by adding suitable crushed rock or chemical compounds to the water. Increasing the ocean's alkalinity enables ocean water to absorb more CO₂ from the atmosphere. OAE is in the early stages of research in China, as it is in the rest of the world. Computer modeling studies have focused on OAE feasibility in the South China Sea and the East China Sea.

One recent study explored the migration pathways of metals in ocean water that would be released if finely ground olivine is distributed in the ocean. The paper proposed strategies for reducing environmental impact to marine life from the metals.

Researchers at Tongji University in Shanghai have proposed adding alkaline minerals to treated wastewater that discharges from wastewater treatment plants into the East China Sea and South China Sea. China has 18,000 km of coastline. Ocean water is acidified where wastewater treatment plants discharge treated water. Distributing alkaline minerals along coastal areas is also proposed where wave action could promote transport and dissolution of the minerals.

Outlook

Geologic CDR methods in China may be characterized as being on the backburner for now, with their high costs and untested status. But if China does eventually ramp up geologic methods of CDR, it would not be a surprise to see it occur on a grand scale like their afforestation projects or their compliance emissions trading platform (the largest in the world). Perhaps the path forward for CDR in China will be spelled out in its upcoming 15th 5-year plan, expected to be revealed at the National People's Congress in March 2026.