evidence: The estimated rate of long-term cooling in the global middle and upper stratosphere (0.6 K decade-1) is similar to previous Assessments. The evolution of stratospheric temperatures continues to follow the behavior expected from the well understood effects of natural and anthropogenic forcings. The long-term trends are primarily driven by changing CO2 and stratospheric ozone. Global temperature in the lower stratosphere has been near constant since the late 1990s. [...] Stratospheric Temperature: The global middle and upper stratosphere continues to cool at a rate of ~-0.6 K decade-1 because of growing levels of well-mixed greenhouse gases (GHGs; primarily carbon dioxide [CO2]) and evolving stratospheric ozone in response to changing ozone-depleting substances (ODSs). Lower-stratospheric temperatures have been near constant since the late 1990s. The overall evolution is consistent with the well-understood effects of ozone, ODSs, GHGs, stratospheric aerosols, and solar variability. This is in agreement with previous Assessments.