Climate Twins is a freely accessible Web application which provides easily comprehensible information on the projected climate developments in Europe at a regional level. Climate Twins is based on the idea that an impression of the future climate of a specific region can be received by indicating regions which have a similar present climate. Within the 7th EU FP project "TaToo" ontology-based functionalities have been added to the basic Climate Twins Web application in order to allow users to enrich the original information base - restricted to only two climate parameters (’temperature’ and ’precipitation’) - by themselves by adding any further geo-located information which they consider relevant in the context of a specific local climate (e.g. information on local vegetation and fauna). This kind of crowdsourcing information raises the problem of safeguarding the quality of the added information. In this paper the authors show how the domain ontology of Climate Twins can be used to semantically validate the coherence of new entries in order to prevent incorrect links.