Citizen sensing from a legal standpoint: Legitimizing the practice under the Aarhus framework

'Citizen sensing', grassroots-driven environmental monitoring, could revolutionize environmental risk governance and decision-making. Yet, citizen sensing is far from being accepted by governmental authorities. This contribution explores the environmental law doctrine and legislation for a possible legal basis on which the 'sensing citizens' could perform their actions. I argue that the practice, by nature, voices the citizen's claims to have access to (accurate) environmental information. I defend that citizen sensing is a legitimate manifestation of 'rights in action' that can enhance the respect of human environmental rights and promote their enforcement. This study demonstrates how, from the Aarhus Convention framework, an obligation for competent authorities to 'listen' to the sensing citizens might even be constructed in case of institutional informational gaps and failures.