The Global Earth Overshoot Day, the date when all annually available natural resources are consumed, is set for July this year. For densely populated European countries like Germany or Switzerland, that specific day is due even earlier (May). To overcome such an unsustainable lifestyle, immediate actions are required, which includes substantial educational efforts. As the model of "Sustainable Development" is complex, appropriate pedagogical actions need to support cognitive learning, critical thinking and behavioural actions. Knowledge about individual conceptions in relation to the Environment, Nature and Ecological Footprints contributes to pre-conditions to succeed. To what extent present teaching methods influenced individual conceptions during the first UN-decade regarding those terms is illustrated by 464 Swiss-German university freshmen who participated in our paper-pencil test, which is based on four open questions. The term of Environment was perceived as the sum of biocentric, ecocentric and anthropocentric views. The participants often equated the term to Nature and associated it with positive feelings or emotions. Therefore, calm, joy and aesthetic appreciation were predominantly named. Regardless of the concept, humans were perceived as the Greatest Environmental Threat. In contrast, recommendations to reduce Environmental Footprints regarding mobility & transport, waste avoidance and consumption differ. Following a binary logistic regression analysis, the involvement of the Inclusion of Self Scale (INS) was used as an explanatory variable to detect patterns of those conceptions. Relating sustainable concepts, natural resources were frequently named exceeding saving water and energy or other association dealt with second-hand issues or regional/ seasonal usages. Such ideas are shaped by experiences and scientific expertise.