Environmental effects of nuclear energy, renewable energy and trade openness in the United States: A wavelet perspective

This study explores the time–frequency nexus between environmental sustainability, proxied by the load capacity factor (LF), and its key drivers—nuclear energy consumption, renewable energy consumption (REC), trade openness, and urbanization—using annual data from 1965 to 2024. Employing a suite of wavelet‐based techniques, including Wavelet Power Spectrum (WPS), Wavelet Transform Coherence (WTC), Multiple Wavelet Coherence (MWC), Partial Wavelet Coherence (PWC), and Wavelet Granger Causality (WGC), the study uncovers dynamic, horizon‐specific relationships. The WPS results reveal high‐frequency volatility during the 1970s oil shocks, medium‐term cycles in the mid‐1990s and 2009, persistent effects from urbanization, and a diminishing role of nuclear energy after the late 1980s. WTC findings indicate a negative LF–NUC relationship with nuclear leading, a REC–LF link that shifts from negative in the 1970s to positive post‐2010, a negative short‐ to medium‐term LF–trade connection, and consistently positive LF–urbanization interactions. MWC results suggest that LF improves most when REC, NUC, and trade interact alongside urban efficiency, while PWC confirms that renewables drive ecological capacity gains even after accounting for other factors. WGC further highlights the role of urbanization as the initial propagator of shocks in the short run, with trade emerging as the dominant transmitter in the long run. Policies are formulated based on these findings.