## 2 Literature Review
[34], and [PERSON] [35] indicate that industrialization and urbanization are associated with increased emissions due to higher energy consumption and transportation needs. These findings align with the broader literature, which suggests that economic development often leads to elevated emissions in the absence of stringent environmental regulations. However, research by [PERSON] et al. [36], [PERSON] et al. [31], and [PERSON] et al. [37] emphasizes that advanced stages of industrialization, characterized by cleaner technologies and more efficient processes, can mitigate these adverse environmental impacts. The role of foreign direct investment in reducing CO2 emissions is explored in studies by [PERSON] et al. [38], [PERSON] et al. [39], and [PERSON] et al. [40]. These researchers argue that foreign direct investment can facilitate the transfer of green technologies and promote sustainable industrial practices. This positive impact of foreign direct investment on environmental sustainability is particularly relevant for OECD countries, which frequently receive substantial foreign investments. By creating favorable conditions for green investments, policymakers can leverage foreign direct investment to achieve their environmental goals. Finally, the relationship between economic growth and CO2 emissions is examined within the framework of the environmental Kuznets curve hypothesis. Studies by [PERSON] et al. [41], [PERSON] et al. [42], and [PERSON] and [PERSON] [43] suggest that while emissions initially increase with economic growth, they eventually decline as economies mature and adopt more sustainable practices. This implies that achieving sustainable development requires integrating environmental considerations into economic planning and leveraging technological advancements to decouple economic growth from carbon emissions. In conclusion, this literature review underscores the critical importance of renewable energy and environmental taxes in mitigating CO2 emissions within OECD countries. While significant progress has been made, the review also reveals a gap in the comprehensive understanding of how these factors interact with other influential variables, such as industrialization, urbanization, foreign direct investment, and economic growth, in determining emissions levels. This study addresses this gap by formulating the research problem as follows: what are the dynamic interactions between renewable energy consumption, environmental taxes, and other socioeconomic factors in influencing CO2 emissions across OECD countries? To answer this question, this study employs the CS-ARDL approach, which allows for a better analysis of both short-term and long-term effects. The findings are expected to inform the development of more effective policy strategies aimed at achieving environmental sustainability and economic growth in tandem. Based on the literature review and research objectives, the following hypotheses are proposed:  
**Hypothesis 1 (H1). **: _Renewable energy consumption has a significant negative impact on CO2 emissions in OECD countries._
**Hypothesis 2 (H2). **: _Environmental taxes are effective in reducing CO2 emissions in OECD countries._
**Hypothesis 3 (H3). **: _The relationship between renewable energy consumption and CO2 emissions varies between the short term and the long term._Hypothesis 4 (H4). : _The effectiveness of environmental taxes on CO2 emission reduction is more pronounced in the long term compared to the short term._