To quantify CH₄ emissions at policy-relevant spatial scales, the Korea Meteorological Administration (KMA) started monitoring its atmospheric levels in 1999 at Anmyeondo (AMY) and expanded monitoring to Jeju Gosan Suwolbong (JGS) and Ulleungdo (ULD) in 2012. The monitoring system consists of a cavity ring-down spectrometer (CRDS) and a new cryogenic drying method, with a measurement uncertainty (68 % c.i. (confidence interval)) of ± 0.7–0.8 ppb. To determine the regional characteristics of CH₄ at each KMA station, we assessed the CH₄ level relative to local background (CH_4xs), analyzed local surface winds and CH₄ with bivariate polar plots, and investigated CH₄ diurnal cycles. We also compared the CH₄ levels measured at KMA stations with those measured at the Mt. Waliguan (WLG) station in China and Ryori (RYO) station in Japan. CH_4xs followed the order AMY (55.3 ± 37.7 ppb) > JGS (24.1 ± 10.2 ppb) > ULD (7.4 ± 3.9 ppb). Although CH₄ was observed in well-mixed air at AMY, it was higher than at other KMA stations, indicating that it was affected not only by local sources but also by distant air masses. Annual mean CH₄ was highest at AMY among all East Asian stations, while its seasonal amplitude was smaller than at JGS, which was strongly affected in the summer by local biogenic activities. From the long-term records at AMY, we confirmed that growth rate increased by 3.3 ppb yr⁻¹ during 2006/2010 and by 8.3 ppb yr⁻¹ from 2016 to 2020, which is similar to the global trend. Studies indicated that the recent global accelerated CH₄-growth rate was related to biogenic sources. However, δ¹³CH₄ indicates that the CH₄ trend in East Asia is derived from both biogenic and fossil fuel sources from 2006 to 2020. We confirmed that long-term high-quality data can help understand changes in CH₄ emissions in East Asia.

In agriculture, balancing water use and retention is an issue dealt with in most regions and for many crops. In this study, we suggest agricultural water equilibrium (AWE) as a new concept that can facilitate a spatially explicit management of agricultural water. This concept is based on the principle of supply and demand of agricultural water, where the virtual water content of crops (VWC) can be defined as the demand, and cropland water budget (CWB) as the supply. For assessing the AWE of the Korean Peninsula, we quantified the CWB based on the hydrological cycle and the VWC of rice, a key crop in the Peninsula. Five factors, namely crop yield, growing season evapotranspiration, annual evapotranspiration, runoff, and annual precipitation, were used to assess the AWE, of which the first four were estimated using the spatially explicit large-scale crop model, Geographical Information System (GIS)-based Environmental Policy Integrated Climate (GEPIC). The CWB and VWC were calculated for a period of three decades, and the AWE was computed by deducting the VWC from the CWB. Our results show a latitudinal difference across the Korean Peninsula. On analyzing the AWE of the major river basins, we found most basins in North Korea showed very low values inferring unsustainable overconsumption of water. The latitudinal difference in AWE is a reflectance of the latitudinal changes in the VWC and CWB. This can be explained by decoupling the demand and supply of agricultural water. Although the AWE values presented in this study were not absolute, the values were sufficient to explain the latitudinal change, and the demand and supply of agricultural water, and establish the usefulness of the indicator.

Global challenges including overpopulation, climate change, and income inequality have increased, and a demand for sustainability has emerged. Decision-making for sustainable development is multifaceted and interlinked, owing to the diverse interests of different stakeholders and political conflicts. Analysing a situation from all social, political, environmental, and economic perspectives is necessary to achieve balanced growth and facilitate sustainable development. South Korea was among the poorest countries following the Korean War; however, it has developed rapidly since 1955. This growth was not limited to economic development alone, and the chronology of South Korean development may serve as a reference for development in other countries. Here, we explore the compressed growth of South Korea using a narrative approach and time-series, comparative, and spatial analyses. Developmental indicators, along with the modern history of South Korea, are introduced to explain the reasons for compressed growth. The development of the mid-latitude region comprising 46 countries in this study, where nearly half of Earth’s population resides, was compared with that of South Korea; results show that the developmental chronology of South Korea can serve as a reference for national development in this region.