Resumen: This paper examines the potential of clean energy stocks and emission permits to reduce downside risk when combining them in a portfolio with dirty energy assets. We propose a strategy for building portfolios that are well diversified between equity energy and carbon markets that takes into account their dynamic price relationship. The asset allocation proposed is framed in a volatility-timing context, which reacts to changing market conditions, holding different weights at different times. To achieve this objective, we use multivariate GARCH models, specifically the Asymmetric Dynamic Conditional Correlations family, which allow us to obtain good estimations of the conditional covariance matrices of the daily asset returns. To determine the weights of the optimum minimum-risk portfolio, we use a method based on Engle and Colacito (2006) to compare the portfolio volatilities obtained with different models. The analysed period runs from January 19, 2010, to April 4, 2022, which, on the one hand, includes more than twelve years of the EU Emissions Trading System (EU ETS) beyond the Phase I pilot; and, on the other, considers the latest crisis episodes (Sovereign debt crisis, Brexit COVID-19, and the recent Russo–Ukrainian war). Our findings show that investing in clean energy companies is now valuable not only because of its contribution to a sustainable energy transition to renewable sources, but also due to its attractiveness from a financial point of view. This fact provides a ray of hope in terms of the climate emergency and avoiding the current geopolitical conflicts principally caused by certain countries’ energy dependence because their energy mix is still heavily overpowered by fossil fuels. The results of this research should encourage investors to decarbonise their equity portfolios, thus promoting the needed alignment of the financial system with the requirements of the energy transition. Idioma: Inglés DOI: 10.1016/j.egyr.2022.11.146 Año: 2022 Publicado en: Energy Reports 8 (2022), 15654-15668 ISSN: 2352-4847 Factor impacto JCR: 5.2 (2022) Categ. JCR: ENERGY & FUELS rank: 55 / 119 = 0.462 (2022) - Q2 - T2 Factor impacto CITESCORE: 5.6 - Energy (Q2)