Engaging college students in service learning (SL) improves students' ability to apply course concepts to "real-world" examples, and it is well documented that participation in service learning has a positive impact on students' classroom learning. Less is known about the role of SL in the online classroom, and several studies suggest that students taking online classes have difficulty connecting course concepts to local and global issues. We hypothesize that integrating an environmental SL component to an online course will lead to more environmentally-aware students who can accurately articulate connections between local and global environmental issues. To address this hypothesis, we have integrated participation in an environmental SL project in two online introductory geoscience courses, as an optional component for a required writing assignment. These SL projects are led by the Center for Earth and Environmental Science (CEES) at locations on and near the IUPUI campus, and students work with environmental managers and community members to address urban environmental issues at each project site. With each SL project, CEES leaders help students connect their ecosystem restoration efforts to concepts learned in class and students complete post-project reflections to assist them in making connections to their classroom learning. To understand the role that the use of SL pedagogy has in facilitating student knowledge acquisition and the application of course concepts, we are measuring student attitudes toward the natural environment, their level of environmental awareness pre- and post-SL project, and their performance on specific exam questions relative to peers that did not participate in the SL experience. In this presentation, we will explore current research on student engagement in the online geoscience course, discuss our implementation of SL in our online classes, and examine results of our research on whether participation in SL leads to increased student understanding of course concepts.