In this paper, we study the speed of extinction of continuous state branching processes in subcritical Lévy environments.More precisely, when the associated Lévy process to the environment drifts to -∞ and, under a suitable exponential change of measure (Esscher transform), the environment either drifts to -∞ or oscillates.We extend recent results of Palau et al. (2016) and Li and Xu (2018), where the branching term is associated to a spectrally positive stable Lévy process and complement the recent article of Bansaye et al. (2021) where the critical case was studied.Our methodology combines a path analysis of the branching process together with its Lévy environment, fluctuation theory for Lévy processes and the asymptotic behaviour of exponential functionals of Lévy processes.As an application of the aforementioned results, we characterise the process conditioned to survival also known as the Q-process.