Participants and session leaders (i.e. users) are allowed to join online web conferences, online meetings, or online classes. The methods herein determine, among other variables, the total air emissions saved by being able to forego physical transportation of the users on account of being able to meet by an online web conference. In certain embodiments, the amount of CO.sub.2 air emissions is determined. The air emission savings are then displayed on a user interface for one or more online web conferences. Aggregate air emission savings may also determined for a group of online web conferences. Advantages of the methods of the present invention include, among others, the ability to quantify the air emission savings from the use of online meeting technology and the ability to generate individualized and aggregated air emission reports based on one or more online web conferences or classes and/or company-wide air emission savings.