Changes in ozone, water vapor, and temperature in the stratosphere were shown to have far-reaching impacts on climate through radiative and dynamical effects. The understanding of the climate response to changes in stratospheric composition is complicated by the interplay between ozone recovery, increasing greenhouse gas concentrations, and stratospheric aerosol changes. We invite papers on causes and impacts of past and future atmospheric changes in the composition of the stratosphere and upper troposphere, including changes due to anthropogenic and natural emissions, geoengineering via solar radiation management, and climate feedbacks in both hemispheres and on all timescales. The attribution of observed and modeled long-term changes in the stratospheric composition, as well as episodic events such as volcanic eruptions and pyrocumulonimbi (pyroCb), and their impact the tropospheric and stratospheric ozone burden will be discussed in this session.