The Geo-collaboration term is applied to collaborative activities in which data and models used by participants are strongly related to geographical locations. There are many scenarios in which Geo-collaboration is used to support a collaborative decision making process. Some of these scenarios are city planning, developing evacuations for emergencies, and developing nature protecting projects. In these situations experts with various backgrounds and knowledge contribute with their opinions and viewpoints. Ideally, the final solution should combine all these viewpoints and all specialists should agree on it. Although the literature reports about procedures for combining decision makers' opinions whose goals might be in contradiction, there are no systems which explicitly support them to reach consensus over a final joint solution. We present a tool which supports this process by allowing experts first, to propose their individual point of view, modeled in the form of beliefs according to the Dempster-Schafer evidence theory. Then, the tool lets participants visualize all proposals, discussing and combining them in a suitable consensual way.