The development of country-specific emission factors in relation to the Agriculture, Forestry, and Other Land Use (AFOLU) sector has the potential to improve national greenhouse gas inventory systems. Forests are carbon sinks in the AFOLU that can play an important role in mitigating global climate change. According to the United Nations Framework Convention on Climate Change (UNFCCC), signatory countries must report forest carbon stocks, and the changes within them, using emission factors from the Intergovernmental Panel on Climate Change (IPCC) or from country-specific values. This study was conducted to estimate forests carbon stocks and to complement and improve the accuracy of national greenhouse gas inventory reporting in South Korea. We developed country-specific emissions factors and estimated carbon stocks and their changes using the different approaches and methods described by the IPCC (IPCC_EF: IPCC default emission factors, CS_FT: country-specific emission factors by forest type, and CS_SP: country-specific emission factors by species). CS_FT returned a result for carbon stocks that was 1.2 times higher than the value using IPCC_EF. Using CS_SP, CO₂ removal was estimated to be 60,648 Gg CO₂ per year with an uncertainty of 22%. Despite a reduction in total forest area, forests continued to store carbon and absorb CO₂, owing to differences in the carbon storage capacities of different forest types and tree species. The results of this study will aid estimations of carbon stock changes and CO₂ removal by forest type or species, and help to improve the completeness and accuracy of the national greenhouse gas inventory. Furthermore, our results provide important information for developing countries implementing Tier 2, the level national greenhouse gas inventory systems recommended by the IPCC.

The United Nations Framework Convention on Climate Change (UNFCCC) recognized the importance of forests in combating climate change and agreed upon financial support for REDD+ activities in developing countries through the Warsaw REDD+ Framework (WRF). The REDD+ activities for conserving carbon stored in forests to reduce GHG emissions and to enhance the carbon sink function of forests are expected to serve as an important means for achieving the climatic goal. In this study, a set of criteria was devised to assess the REDD+ Measuring, Reporting, and Verifying (MRV) implementation capabilities of developing countries, which was applied to analyze the REDD+ MRV levels in REDD+ countries. Based on the Forest Reference Emission Level/Forest Reference Level (FREL/FRL), National Strategy (NS), National Forest Monitoring System (NFMS) and Safeguard Information Summary (SIS) the countries submitted, 36 REDD+ countries submitted only the FREL/FRL (Group I), while 5 countries fulfilled the WRF requirements and registered REDD+ reduction results (Group II), and 6 received Results-Based Payments (RBP) (Group III). From longest to shortest, the periods for which the International Fund provided support were arranged in the order of Group III, II, and I, verifying the relative importance of international support. From highest to lowest, the overall MRV capability was also arranged in the order of Group III, II, and I, although Group I or Group II was at a higher level than the other groups in some elements. REDD+ countries in the Readiness Phase (Group I) would aim to have the MRV capabilities of Groups II and III to receive RBP, and international support for REDD+ MRV capacity building could enable them to do. However, in addition to the receipt of RBP, REDD+ should be reflected in the Nationally Determined Contribution (NDC) as consistent reduction results at the national GHG inventory level, and the advancement of REDD+ MRV is expected to be a necessary and sufficient condition for REDD+ cooperation under the Paris Agreement cooperative approach framework. For the following groups, international cooperation is essential. Countries in the Readiness Phase need to be supported with the establishment of an MRV framework, which will enable them to achieve REDD+ to receive RBP and be reflected in NDCs. For REDD+ countries that have thus far met the WRF requirements, the REDD+ scope needs to be upscaled to national levels, and the MRV system should be further advanced to establish a cooperative approach system that can achieve more ambitious reduction targets through forests.

Nature-based solutions (NbS) is an approach to solving climate change and social issues based on nature. Despite NbS being widely studied as an effective method to solve social problems, the trends in NbS research have hardly been analyzed. Therefore, this study examined change patterns in NbS-related research topics over time and analyzed the interactions of NbS research and relevant activities in various fields. After reviewing research papers based on the search term ‘nature-based solutions’ on Scopus, and collecting 1567 research papers, we conducted dynamic topic modeling (DTM) and network analysis. The papers were classified into 19 topics via DTM. Water, forest, and urban topics made up the greatest portion of NbS research, while NbS topics in the forest sector showed a steady increase over time. This study also found close connections between NbS studies on forests and other sectors and confirmed that the forest sector can become an integrated means of contributing to climate change responses and other resultant social issues. This study demonstrates that DTM and network analysis are useful tools for understanding the trends in NbS research and finding the linkages between various fields.

The REDD+ framework (Reducing Emissions from Deforestation and Forest Degradation, along with sustainable forest management and the conservation and enhancement of forest carbon stocks in developing countries) incentivizes developing countries to reduce greenhouse gas emissions and enhance carbon storage by mitigating deforestation and forest degradation. To receive results-based payments, participating countries must meet United Nations Framework Convention on Climate Change (UNFCCC) requirements for Measurement, Reporting, and Verification (MRV) capacities. This study categorizes developing countries into three phases based on MRV implementation levels: phase 1 (readiness), phase 2 (demonstration), and phase 3 (implementation). Unlike the higher implementation levels observed in phase 2 and phase 3 countries, phase 1 countries have received limited attention due to their early stages of REDD+ implementation. However, assessing the potential of these countries for future REDD+ engagement and Internationally Transferred Mitigation Outcome (ITMO) collaboration is crucial for achieving REDD+ goals. Thus, this study quantitatively assessed MRV capacity among phase 1 countries using an MRV capacity assessment tool, with the goal of identifying high-potential candidates for REDD+ advancement. We applied an MRV capacity assessment tool to 48 phase 1 countries out of the 71 developing countries registered on the REDD+ web platform as of September 2024. The results reveal that (1) the countries with the highest MRV scores were Ghana, India, Guatemala, Liberia, and Mongolia, with Ghana demonstrating strong potential for progression to the implementation phase due to its robust performance in both Measurement and Reporting components. In contrast, Chad scored the lowest, followed by Uruguay, Namibia, Mali, Cuba, and Benin. (2) Overall, phase 1 countries scored lower in the Reporting (R) component, which emphasizes administrative capacity, compared to the Measurement (M) component, which is technically oriented, highlighting the need for improved administrative capacity, particularly in developing and submitting the National Strategy/Action Plan and Safeguard Information System report to meet Cancun Agreement standards. While this study evaluates REDD+ implementation potential in phase 1 countries based on MRV capacity, future research should explore the effectiveness of strengthening MRV capacity through Official Development Assistance (ODA), assessing potential emissions reduction and ITMO potential.

Reliable data on CO₂ quantification is increasingly important to quantify the climate benefits of forest landscape restoration and international commitments, such as the Warsaw REDD+ Framework and Nationally Determined Contributions under the Paris Agreement. Calophyllum inophyllum L. (nyamplung as a local name or tamanu tree for the commercial name) is an increasingly popular tree species in forest landscape restoration and bioenergy production for a variety of reasons. In this paper, we present allometric equations for aboveground biomass (AGB), belowground biomass (BGB), and total above- and belowground biomass (TABGB) predictions of C. inophyllum L. Data collection was carried out twice (2017 and 2021) from 40 trees in Java, Indonesia. Allometric equations using the natural logarithm of diameter at breast height (lnDBH) and ln height (lnH) for biomass prediction qualified the model’s fit with statistical significance at 95% of the confidence interval for AGB, BGB, and TABGB predictions. The results showed that the linear models using both lnDBH and lnH were well fit and accurate. However, the model with lnDBH is more precise than the model using lnH. Using lnDBH as a predictor, the R² values were 0.923, 0.945, and 0.932, and MAPE were 24.7, 37.0, and 25.8 for AGB, BGB, and TABGB, respectively. Using lnH as a predictor, the R² values were 0.887, 0.918, and 0.898 and MAPE were 37.4, 49.0, and 39.8 for AGB, BGB, and TABGB, respectively. Consequently, the driven allometric equations can help accurate biomass quantification for carbon-trading schemes of C. inophyllum L.

This study conducted a systematic literature review focusing on peatlands studies in Southeast Asia, specifically in Jambi, South Sumatra, and the Riau province of Indonesia, covering the period from 2001 to 2023. To ensure the quality and rigor of the analyzed articles, a critical process and systematic review were employed. Journal articles were extracted using reputable resources, including Google Scholar and Scopus, to enhance the validity and reliability of the research results. We identified significant research topics based on region, province, and sector. Additionally, we synthesized the existing classification of ecosystem services, drawing on previous studies conducted in Indonesia. These services were categorized as provisioning, regulating, cultural, and supporting services. We also reviewed the classification of ecosystem service types based on peatland degradation and restoration. This study identified evidence of peatland intervention to evaluate ecosystem services in Indonesia. We found that large-scale cultivation and production of palm oil, local policies, and forest fires were the main intervening factors in Indonesian peatlands. Furthermore, Indonesian peatlands have undergone conversion to oil palm, timber, and crop plantations. It is imperative to substantiate the effectiveness of future peatland restoration plans and further refine the quantification of services provided by peatland ecosystems through cooperative projects.