Dr. Jan Laštovička will talk about "Long-term trends in the upper atmosphere and ionosphere." in the IAP Colloquium on 2nd Dec 2021 at 10:00 AM.  According to his research the increasing concentration of greenhouse gases, particularly of CO, affects the upper atmosphere (mesosphere, thermosphere, and ionosphere) remarkably stronger than the troposphere and surface. However, the effect in the upper atmosphere is greenhouse cooling, not warming. It has more or less impact on all parameters in the upper atmosphere (neutra1, ion and electron temperatures and densities. winds etc,), which is summarized in the qualitatively consistent scenario of global change in the upper atmosphere. Main compounds of this scenario are long-term trends in temperature and electron density at various heights but ii also includes trends in some other parameters like the thermospheric neutral density. On the other hand, there are still significant gaps in the trend scenario, particularly trends in winds and atmospheric wave activity, These gaps and discrepancies will be the topic of investigations in the near future. The greenhouse gases are the main driver of long-term trends in the upper atmosphere but some role is played also by other drivers like ozone or the secular change of the Earth's magnetic field, These other trend drivers are responsible for the trends in the upper atmosphere to vary temporally and spatially to some extent.