Emphasizing the Importance of Accuracy and Reliability in Greenhouse Gas Monitoring for Carbon Neutrality Assessment
The Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report highlights that human-induced greenhouse gas emissions are causing a rise in global surface temperatures, with CO2, CH4, and N2O identified as key contributors to global warming. This underscores the urgency and severity of climate change and calls for intensified global efforts to reduce greenhouse gas emissions. In line with this, South Korea has set a target to reduce greenhouse gas emissions by 40% of the 2018 annual average by 2030 and is actively working toward achieving this goal. The government has enacted the “Framework Act on Carbon Neutrality and Green Growth for Responding to Climate Crisis,” which defines principles and roles for emission reductions, emphasizing local governments' responsibilities and the importance of cooperation between central and regional governments. To fulfill its obligations, the Seoul Metropolitan Government has formulated the “2050 Greenhouse Gas Reduction Plan” and is implementing various initiatives to reduce emissions across sectors. Despite these efforts, certain sectors show stagnation or increases in emissions, raising concerns about achieving reduction targets. This has highlighted the necessity of real-time monitoring to assess and analyze greenhouse gas reduction impacts effectively.
Active Utilization of Directly Measured Greenhouse Gas Emission Data for Monitoring and Policy Application Domestically and Internationally
Typically, greenhouse gas emissions have been monitored using the bottom-up approach based on emission factors and inventories. Similarly, Seoul calculates its emissions using statistical data following established guidelines. However, this method involves uncertainties due to statistical representativeness and data gaps and is limited by the two-year delay in acquiring relevant statistics, restricting real-time and localized monitoring. To address these limitations, the top-down approach, based on direct measurements such as satellite, drone, and aerial observations, along with ground-based monitoring and modeling, is increasingly being adopted. Several countries, including the UK, New Zealand, and Australia, are leveraging such methods for policy validation, verification of bottom-up results, and complementary applications.
Pilot Raman Lidar Observations for Urban Greenhouse Gas Monitoring, the First of Its Kind by a Local Government
This study marks the first use of Raman Lidar, an advanced remote sensing technology, to monitor greenhouse gases across Seoul. Raman Lidar, which employs lasers to measure atmospheric greenhouse gas concentrations, offers high spatial resolution and precise remote measurements of gas concentrations and emissions. The Raman Lidar used in this pilot study demonstrated capabilities such as detecting real-time greenhouse gas distributions with resolutions ranging from 2 to 15 meters along observation paths of up to 1.5 km. Pre-implementation evaluations included reviewing laser wavelengths, mitigating observational obstructions, and validating gas concentration measurement methods through chamber experiments with standard gases, ensuring reliability and objectivity.
Detecting and Monitoring Major Urban Greenhouse Gas Emission Sources in Real-Time
To verify the performance of the Raman Lidar in urban settings, greenhouse gas emissions were continuously monitored near △△ Power Plant, a major emission source. Observations were conducted in collaboration with Hongik University, approximately 1 km from the power plant, from October 2024 for about a month. The Raman Lidar detected sustained high concentrations of CO2 and CH4 (up to 650 ppmv and 14 ppmv, respectively) during power plant operations, with significant diffusion into surrounding areas. Using meteorological data, the estimated emission rates were 330.91±113.21 kg/hr (CO2) and 6.87±113.21 kg/hr (CH4).
Feasibility of Implementing Remote Sensing-Based Greenhouse Gas Monitoring in Seoul
This study utilized advanced Raman Lidar technology to monitor major greenhouse gas emission sources in urban areas, providing high-resolution data on emission concentrations. The data can be integrated with satellite observations to create a comprehensive emission profile, supporting tailored reduction policies and effectiveness evaluations. While initial costs, maintenance, and weather conditions pose challenges, addressing these issues can facilitate systematic monitoring and policy development in Seoul.
Key applications include:
· Region-Specific Policies: Real-time data supports targeted reduction plans for high-emission areas and efficient resource allocation.
Policy Validation and Monitoring: Enables real-time validation of existing measures and enhances responsiveness to emission changes.
· Stronger Emission Regulation: Identifies major emission sources for stricter regulation and automated monitoring systems.
· Integrated Climate Management: Combines greenhouse gas and air pollutant monitoring for holistic environmental management.
· Sustainable Technology Implementation: Promotes collaboration among local governments, research institutes, and health agencies to ensure reliable data collection and system maintenance.