[Cultivating the future with carbon farming] What is the idea of "creating" that will save the Earth?
Updated by Masafumi Yohda on June 11, 2025, 2:33 PM JST
Masafumi YOHDA
Tokyo University of Agriculture and Technology
D. degree in Chemical Engineering from the University of Tokyo. After working as a researcher at Asahi Glass Central Research Laboratory, a full-time researcher at RIKEN, and an associate professor at the Faculty of Engineering, Tokyo University of Agriculture and Technology, he became a professor at the Graduate School of Engineering, TUAT in 2003. He has been a Distinguished Professor at the Graduate School of Engineering of TUAT since April 2025, and is a project leader of the "Carbon Cultivation Center for Challenging the Limits of Carbon Negativity" (FY2023-FY2032) under the JST COI-NEXT (Co-creation Opportunity Formation Support Program). His specialties include structure-function research of proteins called molecular chaperones and development of gene analysis technology.
Greenhouse gases cause global warming. How to reduce carbon dioxide (CO2), the leading cause of global warming, is one of the greatest challenges facing humanity today.
In this context, a unique concept called "carbon farming" has been attracting attention. Based on this new concept of utilizing carbon by "cultivating" it like agriculture, a research and development project is being promoted by the Japan Science and Technology Agency (JST) as one of the centers of its "Co-Creation Opportunity Formation Support Program (COI-NEXT)" led by the Tokyo University of Agriculture and Technology. The project is being conducted mainly at Tokyo University of Agriculture and Technology.
We interviewed Masafumi Yohda, project leader of the Carbon Cultivation Center and specially-appointed professor at Tokyo University of Agriculture and Technology, about the concept and background of the "carbon-cultivated society" that the center aims to achieve.
(Interviewer, composition by Momoko Suda)
--What is the concept of "carbon tillage"?
In a nutshell, it is the concept of "cultivating" not only food, but also fuel and materials. Since ancient times, we have obtained food by cultivating plants. However, human life requires not only food, but also energy and materials.
Long ago, trees were cut from forests to burn and build houses, but today we rely heavily on fossil fuels dug out of the ground, such as petroleum and coal. Petroleum is also used to make plastic and other materials.
Cultivating fuels and materials means cultivating carbon.
This is because the bodies of living organisms, including plants, are made of organic matter, and carbon is the element that forms the framework of organic matter. Petroleum and coal are the result of the transformation of dead organisms (organic matter) such as plants and algae that have remained in the ground for a long time. Life and civilization would not have been possible without carbon.
In other words, we have long used the carbon "fixed" by plants by converting it into organic matter for fuel and materials.
Carbon farming" is the concept of "cultivating" carbon by "making and using" not only food but also fuel and raw materials by human hands.
--Why is such a conception necessary?
The reason is clear: global warming is progressing.
The main cause of current global warming is the increasing concentration of greenhouse gases such as CO2 in the atmosphere.
Going back in Earth's history, it is believed that the prehistoric Earth was a very warm planet, much like Venus. In fact, the concentration of CO2 was much higher than today, but about 3 billion years ago, photosynthetic life appeared and CO2 was gradually reduced.
Later, humans appeared on the scene and learned to use fire and to use plants to make clothes and build houses. Eventually, as civilization emerged, we consumed far more plants than we ate, and as a result, forests were destroyed.
For example, during the Roman Empire, rich forested areas along the Mediterranean coast were cut down, leading to desertification.
Since the Industrial Revolution, underground resources such as coal and oil have been used. However, as the demand for energy has increased with population growth, the destruction of forests is still progressing rapidly.
--So, humans mingled with each other using all forms of above and below ground carbon, resulting in the release of carbon fixed by plants and an increase in atmospheric CO2.
Yes, we have. However, there was a big difference in the way carbon was utilized: for food, and for fuel and materials.
Humans invented agriculture and were able to produce food systematically and in large quantities through cultivation.
On the other hand, as for fuels and materials, until before the Industrial Revolution, we cut down a lot of trees in forests to use as fuel, and we have been using fossil resources "as much as we can take" so to speak. Basically, we have been using both above- and below-ground carbon (from the earth).
Above-ground carbon, such as trees and crops, can be grown back. But carbon in the ground, i.e., fossil resources, cannot be restored once they are used.
Just as with food, we make our own efforts to produce the fuel and materials we need and in the quantities we need. This is the basic idea behind carbon farming.
-- Biomass fuels, which use plants grown on the ground as fuel, have already begun to be introduced around the world.
As for biomass fuels, in the past, the surplus portion of crops used as food was often used as fuel, but this has become problematic not only because of insufficient quantity, but also because of competition with food.
Therefore, it is important to grow plants for the purpose of using them as fuel or materials from the beginning, in other words, to "cultivate" them.
--but there is only a limited amount of farmland on the planet.
Yes, I agree. In Japan, in particular, farmland is quite limited, and we are dependent on imports for much of our food. Furthermore, clearing forests to expand farmland will promote the destruction of nature.
We cannot destroy nature any further.
Therefore, we need to make the best use of the farmland and resources we have. It can be said that technologies are needed to increase the production efficiency of crops and to utilize the carbon obtained from crops without wasting it.
--What does it mean to "use carbon without waste"?
How much of the carbon fixed by plants through photosynthesis can actually be used effectively? This is called "carbon efficiency," and the idea is to increase this efficiency.
For example, when making bioethanol, energy is needed for fermentation and distillation, but a large amount of carbon is lost or additional energy is needed in the process.
No matter how "renewable" it is, it is meaningless if it is inefficient. It is better to have a system that can use twice or three times as much carbon effectively than one that can use only 10% of the fixed amount of carbon.
At the same time, the efficiency of carbon fixation by agricultural products needs to be increased.
To achieve a carbon arable society, technology is needed to increase the efficiency of both of these processes.
*In the second part (Part 2), we will discuss in detail specific research on rice cultivation, forests, and algae, as well as the significance of pursuing this project in Japan.
Momoko Suda(Momoko Suda)
Science Journalist / Specially Appointed Professor at Tokyo University of Agriculture and Technology. In charge of outreach activities at the Carbon Tillage Center. After working for Mainichi Shimbun and NewsPicks, he became independent in November 2024, and received the Investigative Reporting Award Incentive Award, among others, for his September 2023 NewsPicks feature "The False Unicorn: The Dark Side of the Nematode Cancer Test. He is the author of "Fake Scientists: The STAP Cell Case" (Bungeishunju, the Oya Soichi Nonfiction Prize and the Science Journalist Grand Prize) and "The Impact of Synthetic Biology. He is also the co-author of "Who Kills Science: The Impact of the Collapse of a Nation Based on Science and Technology" (Mainichi Newspaper Publishing, Science Journalist Award).
