Hi, Your Carbon footprint should actually decrease. By leaving your home, you will no longer be heating and lighting a home just for one, no longer boiling a jug for one, watching tv etc. Your home carbon output will decrease dramatically, yet the office you will be going to is probably not even going to 'notice' an extra body... being already heated/airconditioned... and the bus is already going that way whether you are on it or not.
In the UK they have run studies on this and to their horror realised that the move to encourage people to work from home was hugely wasteful of resources. We are all better off catching the bus to an office. Yuck.