Are There Carbon-Neutral Cities in South Korea: Using Residual Modeling on Different Spatial Scales

To achieve the national carbon neutrality goal by 2050, it is crucial to be spatially strategic. Understanding the spatial distribution of carbon balance in different levels of spatial scales from global/continental scales to urban, and province/state is essential. This paper aims to estimate the spatial distribution of carbon balance in South Korea using an integrated carbon balance estimation model and to identify the disparity of carbon-emission characteristics determined by three different spatial divisions ¾ metropolitan and basic local governments, and town-level (eup/myeon/dong&li). Two-step ridge regression model using residuals was established based on land cover maps, population maps, and energy production data to analyse the distribution of carbon emissions. The distribution of carbon sequestration was calculated using the Korean forest growth model (KO-G-Dynamic model). The results from each model were calibrated and validated by the National Greenhouse Gas Inventory of basic local governments. The carbon balance was quantified by integrating the results of carbon emission and carbon sequestration. Surprisingly, the results showed that several cities, especially along the biggest mountain range in South Korea, have already achieved regional carbon neutrality. This is particularly true when the spatial scale is below a metropolitan government level. Additionally, the study found that the narrower the spatial scale of distribution becomes, the greater the number of urban/provinces with a carbon balance under zero. Obviously, carbon-neutral regions are characterized by low energy and industrial facilities and high forest density and, in most of the top emitting regions, vice versa. This study provides insights into the methodology for researching the spatial distribution of carbon balance. It also highlights the need for constructing carbon reduction pathways and strategies that reflect the regionality of carbon balance in multi-level districts. With further development of the study, the result could be used as scientific evidence for the effective fulfillment of regional carbon neutrality.