This paper advocates for the integration of environmental aspects in computing curricula, with a focus on higher education. We created knowledge-based curriculum specifications in order to help teachers who wish to add knowledge foundation on computing impacts. This document lists topics and references that can be integrated into curricula. We implemented it in several higher education institutions. This paper reports on our experience and feedback. We also discuss recommendations to overcome obstacles that, from our experience, are often faced when modifying computing curricula to integrate environmental challenges.