The Kolab Groupware Solution offers flexible Personal Information Management (PIM) for professional deployments in companies of almost any size. But since it is Free Software, it can also be used by individual users who care about being in control of their personal information.
There are at least two possible paths to get the information into Google: export from org mode to .ics; upload .ics to a public web server giving it a hidden/secret name; tell Google to import this .ics file use googlecl to import event when you create them into Google calendar (update entries won't be reflected in Google).