## 1 Introduction  
Addressing climate change has become increasingly urgent, particularly in highly industrialized nations such as South Korea, where balancing rapid economic growth with environmental sustainability poses substantial challenges. As one of the world's major exporters and industrial leaders, South Korea relies heavily on energy-intensive sectors such as petrochemicals, steel, and electronics, contributing to high per capita CO\({}_{2}\) emissions. This reliance on carbon-intensive industries underscores the need for policy interventions that can effectively decouple economic growth from environmental degradation, a challenge that becomes more critical as global climate commitments intensify. Trade policy and energy efficiency are pivotal mechanisms in this context. While South Korea's trade liberalization has facilitated industrial expansion and bolstered economic growth, it has simultaneously intensified CO\({}_{2}\) emissions due to the increased energy demands in sectors that are highly carbon-intensive. As documented in the research by [PERSON] and [PERSON] [1] and [PERSON] et al. [2], trade openness, although beneficial for economic growth, often comes at the cost of heightened emissions. However, incorporating energy efficiency standards into trade agreements presents a viable strategy to mitigate these negative externalities. By adopting stringent environmental regulations and promoting energy-efficient technologies, South Korea can lower the carbon intensity of its exports,aligning trade policies with both domestic and global sustainability goals. Furthermore, the role of green technology innovation is crucial in addressing South Korea's environmental challenges. Recent studies emphasize the potential of renewable energy systems, carbon capture technologies, and advanced energy management innovations to significantly reduce CO2 emissions ([PERSON] et al. [3]; [PERSON] et al. [4]). Technological advancements, supported by robust policy frameworks, are vital in accelerating South Korea's transition towards a low-carbon economy. In addition, foreign direct investment (FDI) serves as a critical avenue for emissions reduction, as it facilitates the transfer of cleaner technologies and sustainable practices, contributing to the decoupling of industrial growth from environmental harm. [PERSON] et al. [5] and [PERSON] et al. [6] have highlighted the importance of FDI in promoting the adoption of energy-efficient practices across sectors. South Korea's commitment to reducing CO2 emissions by 40% by 2030, compared to 2018 levels, underscores the pressing need for a swift transition to a low-carbon economy. While the Korean Emissions Trading System provides a crucial policy foundation for incentivizing emissions reductions, a more comprehensive integration of environmental principles into trade and industrial strategies is vital to achieve the nation's ambitious climate goals. This study offers critical insights by quantifying the long-term impacts of trade policy, energy efficiency, and foreign direct investment on CO2 emissions, providing evidence to inform sustainable development pathways for South Korea. Utilizing the advanced Fourier autoregressive distributed lag (FARDL) methodology, which accounts for both short- and long-term effects and adjusts for structural breaks and non-linearities, the research highlights the immediate rise in CO2 emissions driven by trade liberalization, particularly in energy-intensive industries. Over time, however, the inclusion of energy efficiency standards within trade agreements mitigates these impacts, leading to a net decrease in emissions. The study further emphasizes the significant role of FDI and advancements in green technology in reducing carbon intensity, showcasing the importance of aligning trade policies with environmental sustainability goals. The findings offer robust empirical support for the promotion of energy-efficient technologies and environmentally conscious trade policies as pivotal elements in South Korea's journey toward a low-carbon future.