We present here an overview of different types and levels of interaction between the bisophere and the Geosphere. With changing concepts in atmospheric environment, the interactive processes need to be viewed over a larger convas than normally considered. The two major departures made are to include not only the troposphere and the stratosphere but also the middle atmosphere, and also to look at both neutral and ion components in the interactive processes. The specific aspects considered include: nature and variety of interactions; key question and parameters; basic chemistries involved (both neutral and ionic); chemistries of greenhouse gases and of ozone; and a short outline of the Indian contributions and existing and planned facilities.