How Japan can lead in forest mapping to maximize climate change mitigation

Forests play a crucial role in the global fight against climate change. Covering roughly a third of the Earth's land area, forests are effective in carbon sequestration — absorbing carbon dioxide from the atmosphere as trees grow, capturing it within their branches and leaves. Between 2001 and 2019, forests absorbed roughly 7.6 billion tons of carbon dioxide each year, according to NASA.

The amount of carbon dioxide a forest can absorb depends on factors including forest condition, tree density and species diversity. The Learning Museum of the Forest and Forestry in Japan notes that cedar trees between 11 and 20-years-old absorb three times more carbon dioxide than sawtooth oaks of the same age. Many trees also tend to absorb more carbon dioxide when they’re younger, slowing as they age. A University of Tokyo study found that carbon sequestration is three to four times higher in forests with double the amount of logging and replanting compared to forests without these practices.

Having accurate, comprehensive information on forests is essential in developing the best strategies for fighting climate change. In Japan, the public and private sectors are collaborating to create and share detailed forest maps to support climate policy and maximize forests' carbon-capturing potential.

With forests covering 67% of Japan’s land area, the country is focusing on them as part of its strategy to combat climate change. One key initiative is the J-Credit Scheme, which certifies greenhouse gas reductions and carbon absorption achieved through forest management and other activities.

Due to the vastness of Japan’s forests, collecting precise data has been challenging. The J-Credit Scheme and similar programmes have largely relied on carbon estimates derived from tree species inventories, forest age data and field surveys, which often lack specific location details. In recent years, advancements in technology, notably lasers, has been instrumental in creating more accurate forest maps. The Forestry Agency has been actively supporting efforts to collect detailed forest data using the latest technologies.

Building on these advancements, a research team from the University of Tokyo released a high-resolution forest map in October 2024, utilizing advanced satellite data to show forest structure and carbon stocks across Japan. This new map revealed that previously estimated carbon stocks were significantly underestimated, highlighting the critical role of current, precise forest data in climate action efforts.

Alongside the condition of the trees, a forest's ecosystem also impacts its carbon sequestration potential. Research by Kyushu University shows that an increase in deer populations can cut a forest’s carbon storage capacity in half. When deer populations become too large, they excessively feed on certain plants, disrupting the balance and rapidly changing the forest structure.

Based on this finding, an industry-academia project was recently launched between six companies, including Yamaha Motor, and Kyushu University. Yamaha Motor is working to quantify not only the trees but the entire ecosystem. Using Light Detection and Ranging technology, also known as LIDAR, mounted on an unmanned Yamaha helicopter, the team will conduct a demonstration in a western Tokyo forest to develop a highly precise method for measuring carbon absorption and other ecosystem data. The project will quantify biodiversity by assessing vegetation structure and animal species — including birds, mammals, and insects — within the test site. This data will help predict the forest’s future carbon absorption capacity, offering insights into sustainable ecosystem management.

Part of the effort by the Forestry Agency also includes converting collected forest data into digital formats and making it open source. In the past, forest data in Japan was primarily used within the forestry sector, limited to sharing among government agencies, forestry companies and other related organizations within each prefecture. With open data, a wider range of companies and organizations can leverage this data.

Analyzing open source data makes it possible to identify management practices that maximize carbon sequestration for specific forests in different regions. This information helps local governments and businesses make more effective use of forests to reduce carbon dioxide emissions, supporting significant progress toward future emissions reduction goals.

The World Economic Forum’s Forests for Climate initiative, promotes “large‐scale forest conservation to help meet the goals of the Paris climate agreement” by engaging the public and private sectors. Japan's leadership to map and openly share detailed forest data will enable government and industry to implement data-driven strategies for better forest management. This will help boost the ability of Japan's forests to absorb carbon and strengthen the country’s role in fighting global carbon emissions.