Higher-order moment risk spillovers between the carbon and energy markets under climate policy uncertainty

Against the backdrop of increasing climate policy uncertainty, preventing cross-market risk contagion in the energy transition is crucial to ensuring energy security and effective risk management. First, this study uses the generalized autoregressive conditional heteroskedasticity-skewness-kurtosis (GARCHSK) model to measure the higher-order moment risk of the carbon and energy markets. Then, based on the quantile spillover index model, the higher-order moment risk spillover effects and their time-varying characteristics in different risk states are characterized. Furthermore, the climate policy uncertainty index (CPU) is incorporated into the generalized autoregressive conditional heteroskedasticity-mixed data sampling (GARCH-MIDAS) model to analyze its impact on higher-order moment risk spillover effects. The empirical results show that (1) there is a higher-order moment risk spillover effect between the carbon and energy markets, but its spillover level is weaker than the lower-order moment risk spillover effect; (2) risk spillover effects between the carbon and energy markets vary significantly in different risk states, with higher levels of risk spillover occurring in extreme risk states; and (3) climate policy uncertainty exacerbates the risk spillover effects between the carbon and energy markets and has a greater impact on higher-order moment risk spillover effects. The research findings contribute to a more accurate understanding of risk spillover patterns and driving mechanisms between the carbon and energy markets.