Exploring connectedness among clean energy, cleantech, and climate change: empirical evidence in the wake of contemporary asymmetrical crisis

This study investigates the interconnectedness among clean energy, cleantech, and climate change indices across three critical time periods: pre-COVID-19 (June 2019–March 2020), the COVID-19 pandemic (March 2020–February 2022), and post-COVID-19 (February 2022–February 2024). Using daily data from Refinitiv Datastream, the analysis employs the Diebold and Yilmaz (Econ J 119(534):158–171, 2009) spillover index methodology to evaluate volatility spillovers among these indices. Stationarity of the time series is confirmed using the Augmented Dickey-Fuller (ADF) test, and a Vector Autoregression (VAR) model is applied to capture dynamic interactions. Results reveal heightened volatility spillovers during the COVID-19 pandemic, reflecting increased market interdependence, while the post-COVID-19 period shows persistent but moderated spillovers influenced by geopolitical tensions and global economic uncertainties. The findings underscore the resilience of green investments during crises and their critical role in promoting sustainable economic transitions. This study contributes to the literature on green finance by expanding the studying of the volatility spillover of major events in terms of global instability and offering simple rules for stakeholders and decision-makers on the risks of financial markets.